1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Security-Enhanced Linux (SELinux) security module
4 *
5 * This file contains the SELinux hook function implementations.
6 *
7 * Authors: Stephen Smalley, <stephen.smalley.work@gmail.com>
8 * Chris Vance, <cvance@nai.com>
9 * Wayne Salamon, <wsalamon@nai.com>
10 * James Morris <jmorris@redhat.com>
11 *
12 * Copyright (C) 2001,2002 Networks Associates Technology, Inc.
13 * Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
14 * Eric Paris <eparis@redhat.com>
15 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
16 * <dgoeddel@trustedcs.com>
17 * Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
18 * Paul Moore <paul@paul-moore.com>
19 * Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
20 * Yuichi Nakamura <ynakam@hitachisoft.jp>
21 * Copyright (C) 2016 Mellanox Technologies
22 */
23
24 #include <linux/init.h>
25 #include <linux/kd.h>
26 #include <linux/kernel.h>
27 #include <linux/kernel_read_file.h>
28 #include <linux/errno.h>
29 #include <linux/sched/signal.h>
30 #include <linux/sched/task.h>
31 #include <linux/lsm_hooks.h>
32 #include <linux/xattr.h>
33 #include <linux/capability.h>
34 #include <linux/unistd.h>
35 #include <linux/mm.h>
36 #include <linux/mman.h>
37 #include <linux/slab.h>
38 #include <linux/pagemap.h>
39 #include <linux/proc_fs.h>
40 #include <linux/swap.h>
41 #include <linux/spinlock.h>
42 #include <linux/syscalls.h>
43 #include <linux/dcache.h>
44 #include <linux/file.h>
45 #include <linux/fdtable.h>
46 #include <linux/namei.h>
47 #include <linux/mount.h>
48 #include <linux/fs_context.h>
49 #include <linux/fs_parser.h>
50 #include <linux/netfilter_ipv4.h>
51 #include <linux/netfilter_ipv6.h>
52 #include <linux/tty.h>
53 #include <net/icmp.h>
54 #include <net/ip.h> /* for local_port_range[] */
55 #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
56 #include <net/inet_connection_sock.h>
57 #include <net/net_namespace.h>
58 #include <net/netlabel.h>
59 #include <linux/uaccess.h>
60 #include <asm/ioctls.h>
61 #include <linux/atomic.h>
62 #include <linux/bitops.h>
63 #include <linux/interrupt.h>
64 #include <linux/netdevice.h> /* for network interface checks */
65 #include <net/netlink.h>
66 #include <linux/tcp.h>
67 #include <linux/udp.h>
68 #include <linux/dccp.h>
69 #include <linux/sctp.h>
70 #include <net/sctp/structs.h>
71 #include <linux/quota.h>
72 #include <linux/un.h> /* for Unix socket types */
73 #include <net/af_unix.h> /* for Unix socket types */
74 #include <linux/parser.h>
75 #include <linux/nfs_mount.h>
76 #include <net/ipv6.h>
77 #include <linux/hugetlb.h>
78 #include <linux/personality.h>
79 #include <linux/audit.h>
80 #include <linux/string.h>
81 #include <linux/mutex.h>
82 #include <linux/posix-timers.h>
83 #include <linux/syslog.h>
84 #include <linux/user_namespace.h>
85 #include <linux/export.h>
86 #include <linux/msg.h>
87 #include <linux/shm.h>
88 #include <uapi/linux/shm.h>
89 #include <linux/bpf.h>
90 #include <linux/kernfs.h>
91 #include <linux/stringhash.h> /* for hashlen_string() */
92 #include <uapi/linux/mount.h>
93 #include <linux/fsnotify.h>
94 #include <linux/fanotify.h>
95 #include <linux/io_uring/cmd.h>
96 #include <uapi/linux/lsm.h>
97
98 #include "avc.h"
99 #include "objsec.h"
100 #include "netif.h"
101 #include "netnode.h"
102 #include "netport.h"
103 #include "ibpkey.h"
104 #include "xfrm.h"
105 #include "netlabel.h"
106 #include "audit.h"
107 #include "avc_ss.h"
108
109 #define SELINUX_INODE_INIT_XATTRS 1
110
111 struct selinux_state selinux_state;
112
113 /* SECMARK reference count */
114 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
115
116 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
117 static int selinux_enforcing_boot __initdata;
118
enforcing_setup(char * str)119 static int __init enforcing_setup(char *str)
120 {
121 unsigned long enforcing;
122 if (!kstrtoul(str, 0, &enforcing))
123 selinux_enforcing_boot = enforcing ? 1 : 0;
124 return 1;
125 }
126 __setup("enforcing=", enforcing_setup);
127 #else
128 #define selinux_enforcing_boot 1
129 #endif
130
131 int selinux_enabled_boot __initdata = 1;
132 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
selinux_enabled_setup(char * str)133 static int __init selinux_enabled_setup(char *str)
134 {
135 unsigned long enabled;
136 if (!kstrtoul(str, 0, &enabled))
137 selinux_enabled_boot = enabled ? 1 : 0;
138 return 1;
139 }
140 __setup("selinux=", selinux_enabled_setup);
141 #endif
142
checkreqprot_setup(char * str)143 static int __init checkreqprot_setup(char *str)
144 {
145 unsigned long checkreqprot;
146
147 if (!kstrtoul(str, 0, &checkreqprot)) {
148 if (checkreqprot)
149 pr_err("SELinux: checkreqprot set to 1 via kernel parameter. This is no longer supported.\n");
150 }
151 return 1;
152 }
153 __setup("checkreqprot=", checkreqprot_setup);
154
155 /**
156 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
157 *
158 * Description:
159 * This function checks the SECMARK reference counter to see if any SECMARK
160 * targets are currently configured, if the reference counter is greater than
161 * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is
162 * enabled, false (0) if SECMARK is disabled. If the always_check_network
163 * policy capability is enabled, SECMARK is always considered enabled.
164 *
165 */
selinux_secmark_enabled(void)166 static int selinux_secmark_enabled(void)
167 {
168 return (selinux_policycap_alwaysnetwork() ||
169 atomic_read(&selinux_secmark_refcount));
170 }
171
172 /**
173 * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled
174 *
175 * Description:
176 * This function checks if NetLabel or labeled IPSEC is enabled. Returns true
177 * (1) if any are enabled or false (0) if neither are enabled. If the
178 * always_check_network policy capability is enabled, peer labeling
179 * is always considered enabled.
180 *
181 */
selinux_peerlbl_enabled(void)182 static int selinux_peerlbl_enabled(void)
183 {
184 return (selinux_policycap_alwaysnetwork() ||
185 netlbl_enabled() || selinux_xfrm_enabled());
186 }
187
selinux_netcache_avc_callback(u32 event)188 static int selinux_netcache_avc_callback(u32 event)
189 {
190 if (event == AVC_CALLBACK_RESET) {
191 sel_netif_flush();
192 sel_netnode_flush();
193 sel_netport_flush();
194 synchronize_net();
195 }
196 return 0;
197 }
198
selinux_lsm_notifier_avc_callback(u32 event)199 static int selinux_lsm_notifier_avc_callback(u32 event)
200 {
201 if (event == AVC_CALLBACK_RESET) {
202 sel_ib_pkey_flush();
203 call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL);
204 }
205
206 return 0;
207 }
208
209 /*
210 * initialise the security for the init task
211 */
cred_init_security(void)212 static void cred_init_security(void)
213 {
214 struct task_security_struct *tsec;
215
216 tsec = selinux_cred(unrcu_pointer(current->real_cred));
217 tsec->osid = tsec->sid = SECINITSID_KERNEL;
218 }
219
220 /*
221 * get the security ID of a set of credentials
222 */
cred_sid(const struct cred * cred)223 static inline u32 cred_sid(const struct cred *cred)
224 {
225 const struct task_security_struct *tsec;
226
227 tsec = selinux_cred(cred);
228 return tsec->sid;
229 }
230
__ad_net_init(struct common_audit_data * ad,struct lsm_network_audit * net,int ifindex,struct sock * sk,u16 family)231 static void __ad_net_init(struct common_audit_data *ad,
232 struct lsm_network_audit *net,
233 int ifindex, struct sock *sk, u16 family)
234 {
235 ad->type = LSM_AUDIT_DATA_NET;
236 ad->u.net = net;
237 net->netif = ifindex;
238 net->sk = sk;
239 net->family = family;
240 }
241
ad_net_init_from_sk(struct common_audit_data * ad,struct lsm_network_audit * net,struct sock * sk)242 static void ad_net_init_from_sk(struct common_audit_data *ad,
243 struct lsm_network_audit *net,
244 struct sock *sk)
245 {
246 __ad_net_init(ad, net, 0, sk, 0);
247 }
248
ad_net_init_from_iif(struct common_audit_data * ad,struct lsm_network_audit * net,int ifindex,u16 family)249 static void ad_net_init_from_iif(struct common_audit_data *ad,
250 struct lsm_network_audit *net,
251 int ifindex, u16 family)
252 {
253 __ad_net_init(ad, net, ifindex, NULL, family);
254 }
255
256 /*
257 * get the objective security ID of a task
258 */
task_sid_obj(const struct task_struct * task)259 static inline u32 task_sid_obj(const struct task_struct *task)
260 {
261 u32 sid;
262
263 rcu_read_lock();
264 sid = cred_sid(__task_cred(task));
265 rcu_read_unlock();
266 return sid;
267 }
268
269 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
270
271 /*
272 * Try reloading inode security labels that have been marked as invalid. The
273 * @may_sleep parameter indicates when sleeping and thus reloading labels is
274 * allowed; when set to false, returns -ECHILD when the label is
275 * invalid. The @dentry parameter should be set to a dentry of the inode.
276 */
__inode_security_revalidate(struct inode * inode,struct dentry * dentry,bool may_sleep)277 static int __inode_security_revalidate(struct inode *inode,
278 struct dentry *dentry,
279 bool may_sleep)
280 {
281 struct inode_security_struct *isec = selinux_inode(inode);
282
283 might_sleep_if(may_sleep);
284
285 /*
286 * The check of isec->initialized below is racy but
287 * inode_doinit_with_dentry() will recheck with
288 * isec->lock held.
289 */
290 if (selinux_initialized() &&
291 data_race(isec->initialized != LABEL_INITIALIZED)) {
292 if (!may_sleep)
293 return -ECHILD;
294
295 /*
296 * Try reloading the inode security label. This will fail if
297 * @opt_dentry is NULL and no dentry for this inode can be
298 * found; in that case, continue using the old label.
299 */
300 inode_doinit_with_dentry(inode, dentry);
301 }
302 return 0;
303 }
304
inode_security_novalidate(struct inode * inode)305 static struct inode_security_struct *inode_security_novalidate(struct inode *inode)
306 {
307 return selinux_inode(inode);
308 }
309
inode_security_rcu(struct inode * inode,bool rcu)310 static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu)
311 {
312 int error;
313
314 error = __inode_security_revalidate(inode, NULL, !rcu);
315 if (error)
316 return ERR_PTR(error);
317 return selinux_inode(inode);
318 }
319
320 /*
321 * Get the security label of an inode.
322 */
inode_security(struct inode * inode)323 static struct inode_security_struct *inode_security(struct inode *inode)
324 {
325 __inode_security_revalidate(inode, NULL, true);
326 return selinux_inode(inode);
327 }
328
backing_inode_security_novalidate(struct dentry * dentry)329 static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry)
330 {
331 struct inode *inode = d_backing_inode(dentry);
332
333 return selinux_inode(inode);
334 }
335
336 /*
337 * Get the security label of a dentry's backing inode.
338 */
backing_inode_security(struct dentry * dentry)339 static struct inode_security_struct *backing_inode_security(struct dentry *dentry)
340 {
341 struct inode *inode = d_backing_inode(dentry);
342
343 __inode_security_revalidate(inode, dentry, true);
344 return selinux_inode(inode);
345 }
346
inode_free_security(struct inode * inode)347 static void inode_free_security(struct inode *inode)
348 {
349 struct inode_security_struct *isec = selinux_inode(inode);
350 struct superblock_security_struct *sbsec;
351
352 if (!isec)
353 return;
354 sbsec = selinux_superblock(inode->i_sb);
355 /*
356 * As not all inode security structures are in a list, we check for
357 * empty list outside of the lock to make sure that we won't waste
358 * time taking a lock doing nothing.
359 *
360 * The list_del_init() function can be safely called more than once.
361 * It should not be possible for this function to be called with
362 * concurrent list_add(), but for better safety against future changes
363 * in the code, we use list_empty_careful() here.
364 */
365 if (!list_empty_careful(&isec->list)) {
366 spin_lock(&sbsec->isec_lock);
367 list_del_init(&isec->list);
368 spin_unlock(&sbsec->isec_lock);
369 }
370 }
371
372 struct selinux_mnt_opts {
373 u32 fscontext_sid;
374 u32 context_sid;
375 u32 rootcontext_sid;
376 u32 defcontext_sid;
377 };
378
selinux_free_mnt_opts(void * mnt_opts)379 static void selinux_free_mnt_opts(void *mnt_opts)
380 {
381 kfree(mnt_opts);
382 }
383
384 enum {
385 Opt_error = -1,
386 Opt_context = 0,
387 Opt_defcontext = 1,
388 Opt_fscontext = 2,
389 Opt_rootcontext = 3,
390 Opt_seclabel = 4,
391 };
392
393 #define A(s, has_arg) {#s, sizeof(#s) - 1, Opt_##s, has_arg}
394 static const struct {
395 const char *name;
396 int len;
397 int opt;
398 bool has_arg;
399 } tokens[] = {
400 A(context, true),
401 A(fscontext, true),
402 A(defcontext, true),
403 A(rootcontext, true),
404 A(seclabel, false),
405 };
406 #undef A
407
match_opt_prefix(char * s,int l,char ** arg)408 static int match_opt_prefix(char *s, int l, char **arg)
409 {
410 int i;
411
412 for (i = 0; i < ARRAY_SIZE(tokens); i++) {
413 size_t len = tokens[i].len;
414 if (len > l || memcmp(s, tokens[i].name, len))
415 continue;
416 if (tokens[i].has_arg) {
417 if (len == l || s[len] != '=')
418 continue;
419 *arg = s + len + 1;
420 } else if (len != l)
421 continue;
422 return tokens[i].opt;
423 }
424 return Opt_error;
425 }
426
427 #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
428
may_context_mount_sb_relabel(u32 sid,struct superblock_security_struct * sbsec,const struct cred * cred)429 static int may_context_mount_sb_relabel(u32 sid,
430 struct superblock_security_struct *sbsec,
431 const struct cred *cred)
432 {
433 const struct task_security_struct *tsec = selinux_cred(cred);
434 int rc;
435
436 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
437 FILESYSTEM__RELABELFROM, NULL);
438 if (rc)
439 return rc;
440
441 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
442 FILESYSTEM__RELABELTO, NULL);
443 return rc;
444 }
445
may_context_mount_inode_relabel(u32 sid,struct superblock_security_struct * sbsec,const struct cred * cred)446 static int may_context_mount_inode_relabel(u32 sid,
447 struct superblock_security_struct *sbsec,
448 const struct cred *cred)
449 {
450 const struct task_security_struct *tsec = selinux_cred(cred);
451 int rc;
452 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
453 FILESYSTEM__RELABELFROM, NULL);
454 if (rc)
455 return rc;
456
457 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
458 FILESYSTEM__ASSOCIATE, NULL);
459 return rc;
460 }
461
selinux_is_genfs_special_handling(struct super_block * sb)462 static int selinux_is_genfs_special_handling(struct super_block *sb)
463 {
464 /* Special handling. Genfs but also in-core setxattr handler */
465 return !strcmp(sb->s_type->name, "sysfs") ||
466 !strcmp(sb->s_type->name, "pstore") ||
467 !strcmp(sb->s_type->name, "debugfs") ||
468 !strcmp(sb->s_type->name, "tracefs") ||
469 !strcmp(sb->s_type->name, "rootfs") ||
470 (selinux_policycap_cgroupseclabel() &&
471 (!strcmp(sb->s_type->name, "cgroup") ||
472 !strcmp(sb->s_type->name, "cgroup2"))) ||
473 // Android: remove functionfs policycap check due to
474 // ABI breakage with policycap array.
475 !strcmp(sb->s_type->name, "functionfs");
476 }
477
selinux_is_sblabel_mnt(struct super_block * sb)478 static int selinux_is_sblabel_mnt(struct super_block *sb)
479 {
480 struct superblock_security_struct *sbsec = selinux_superblock(sb);
481
482 /*
483 * IMPORTANT: Double-check logic in this function when adding a new
484 * SECURITY_FS_USE_* definition!
485 */
486 BUILD_BUG_ON(SECURITY_FS_USE_MAX != 7);
487
488 switch (sbsec->behavior) {
489 case SECURITY_FS_USE_XATTR:
490 case SECURITY_FS_USE_TRANS:
491 case SECURITY_FS_USE_TASK:
492 case SECURITY_FS_USE_NATIVE:
493 return 1;
494
495 case SECURITY_FS_USE_GENFS:
496 return selinux_is_genfs_special_handling(sb);
497
498 /* Never allow relabeling on context mounts */
499 case SECURITY_FS_USE_MNTPOINT:
500 case SECURITY_FS_USE_NONE:
501 default:
502 return 0;
503 }
504 }
505
sb_check_xattr_support(struct super_block * sb)506 static int sb_check_xattr_support(struct super_block *sb)
507 {
508 struct superblock_security_struct *sbsec = selinux_superblock(sb);
509 struct dentry *root = sb->s_root;
510 struct inode *root_inode = d_backing_inode(root);
511 u32 sid;
512 int rc;
513
514 /*
515 * Make sure that the xattr handler exists and that no
516 * error other than -ENODATA is returned by getxattr on
517 * the root directory. -ENODATA is ok, as this may be
518 * the first boot of the SELinux kernel before we have
519 * assigned xattr values to the filesystem.
520 */
521 if (!(root_inode->i_opflags & IOP_XATTR)) {
522 pr_warn("SELinux: (dev %s, type %s) has no xattr support\n",
523 sb->s_id, sb->s_type->name);
524 goto fallback;
525 }
526
527 rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0);
528 if (rc < 0 && rc != -ENODATA) {
529 if (rc == -EOPNOTSUPP) {
530 pr_warn("SELinux: (dev %s, type %s) has no security xattr handler\n",
531 sb->s_id, sb->s_type->name);
532 goto fallback;
533 } else {
534 pr_warn("SELinux: (dev %s, type %s) getxattr errno %d\n",
535 sb->s_id, sb->s_type->name, -rc);
536 return rc;
537 }
538 }
539 return 0;
540
541 fallback:
542 /* No xattr support - try to fallback to genfs if possible. */
543 rc = security_genfs_sid(sb->s_type->name, "/",
544 SECCLASS_DIR, &sid);
545 if (rc)
546 return -EOPNOTSUPP;
547
548 pr_warn("SELinux: (dev %s, type %s) falling back to genfs\n",
549 sb->s_id, sb->s_type->name);
550 sbsec->behavior = SECURITY_FS_USE_GENFS;
551 sbsec->sid = sid;
552 return 0;
553 }
554
sb_finish_set_opts(struct super_block * sb)555 static int sb_finish_set_opts(struct super_block *sb)
556 {
557 struct superblock_security_struct *sbsec = selinux_superblock(sb);
558 struct dentry *root = sb->s_root;
559 struct inode *root_inode = d_backing_inode(root);
560 int rc = 0;
561
562 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
563 rc = sb_check_xattr_support(sb);
564 if (rc)
565 return rc;
566 }
567
568 sbsec->flags |= SE_SBINITIALIZED;
569
570 /*
571 * Explicitly set or clear SBLABEL_MNT. It's not sufficient to simply
572 * leave the flag untouched because sb_clone_mnt_opts might be handing
573 * us a superblock that needs the flag to be cleared.
574 */
575 if (selinux_is_sblabel_mnt(sb))
576 sbsec->flags |= SBLABEL_MNT;
577 else
578 sbsec->flags &= ~SBLABEL_MNT;
579
580 /* Initialize the root inode. */
581 rc = inode_doinit_with_dentry(root_inode, root);
582
583 /* Initialize any other inodes associated with the superblock, e.g.
584 inodes created prior to initial policy load or inodes created
585 during get_sb by a pseudo filesystem that directly
586 populates itself. */
587 spin_lock(&sbsec->isec_lock);
588 while (!list_empty(&sbsec->isec_head)) {
589 struct inode_security_struct *isec =
590 list_first_entry(&sbsec->isec_head,
591 struct inode_security_struct, list);
592 struct inode *inode = isec->inode;
593 list_del_init(&isec->list);
594 spin_unlock(&sbsec->isec_lock);
595 inode = igrab(inode);
596 if (inode) {
597 if (!IS_PRIVATE(inode))
598 inode_doinit_with_dentry(inode, NULL);
599 iput(inode);
600 }
601 spin_lock(&sbsec->isec_lock);
602 }
603 spin_unlock(&sbsec->isec_lock);
604 return rc;
605 }
606
bad_option(struct superblock_security_struct * sbsec,char flag,u32 old_sid,u32 new_sid)607 static int bad_option(struct superblock_security_struct *sbsec, char flag,
608 u32 old_sid, u32 new_sid)
609 {
610 char mnt_flags = sbsec->flags & SE_MNTMASK;
611
612 /* check if the old mount command had the same options */
613 if (sbsec->flags & SE_SBINITIALIZED)
614 if (!(sbsec->flags & flag) ||
615 (old_sid != new_sid))
616 return 1;
617
618 /* check if we were passed the same options twice,
619 * aka someone passed context=a,context=b
620 */
621 if (!(sbsec->flags & SE_SBINITIALIZED))
622 if (mnt_flags & flag)
623 return 1;
624 return 0;
625 }
626
627 /*
628 * Allow filesystems with binary mount data to explicitly set mount point
629 * labeling information.
630 */
selinux_set_mnt_opts(struct super_block * sb,void * mnt_opts,unsigned long kern_flags,unsigned long * set_kern_flags)631 static int selinux_set_mnt_opts(struct super_block *sb,
632 void *mnt_opts,
633 unsigned long kern_flags,
634 unsigned long *set_kern_flags)
635 {
636 const struct cred *cred = current_cred();
637 struct superblock_security_struct *sbsec = selinux_superblock(sb);
638 struct dentry *root = sb->s_root;
639 struct selinux_mnt_opts *opts = mnt_opts;
640 struct inode_security_struct *root_isec;
641 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
642 u32 defcontext_sid = 0;
643 int rc = 0;
644
645 /*
646 * Specifying internal flags without providing a place to
647 * place the results is not allowed
648 */
649 if (kern_flags && !set_kern_flags)
650 return -EINVAL;
651
652 mutex_lock(&sbsec->lock);
653
654 if (!selinux_initialized()) {
655 if (!opts) {
656 /* Defer initialization until selinux_complete_init,
657 after the initial policy is loaded and the security
658 server is ready to handle calls. */
659 if (kern_flags & SECURITY_LSM_NATIVE_LABELS) {
660 sbsec->flags |= SE_SBNATIVE;
661 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
662 }
663 goto out;
664 }
665 rc = -EINVAL;
666 pr_warn("SELinux: Unable to set superblock options "
667 "before the security server is initialized\n");
668 goto out;
669 }
670
671 /*
672 * Binary mount data FS will come through this function twice. Once
673 * from an explicit call and once from the generic calls from the vfs.
674 * Since the generic VFS calls will not contain any security mount data
675 * we need to skip the double mount verification.
676 *
677 * This does open a hole in which we will not notice if the first
678 * mount using this sb set explicit options and a second mount using
679 * this sb does not set any security options. (The first options
680 * will be used for both mounts)
681 */
682 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
683 && !opts)
684 goto out;
685
686 root_isec = backing_inode_security_novalidate(root);
687
688 /*
689 * parse the mount options, check if they are valid sids.
690 * also check if someone is trying to mount the same sb more
691 * than once with different security options.
692 */
693 if (opts) {
694 if (opts->fscontext_sid) {
695 fscontext_sid = opts->fscontext_sid;
696 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
697 fscontext_sid))
698 goto out_double_mount;
699 sbsec->flags |= FSCONTEXT_MNT;
700 }
701 if (opts->context_sid) {
702 context_sid = opts->context_sid;
703 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
704 context_sid))
705 goto out_double_mount;
706 sbsec->flags |= CONTEXT_MNT;
707 }
708 if (opts->rootcontext_sid) {
709 rootcontext_sid = opts->rootcontext_sid;
710 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
711 rootcontext_sid))
712 goto out_double_mount;
713 sbsec->flags |= ROOTCONTEXT_MNT;
714 }
715 if (opts->defcontext_sid) {
716 defcontext_sid = opts->defcontext_sid;
717 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
718 defcontext_sid))
719 goto out_double_mount;
720 sbsec->flags |= DEFCONTEXT_MNT;
721 }
722 }
723
724 if (sbsec->flags & SE_SBINITIALIZED) {
725 /* previously mounted with options, but not on this attempt? */
726 if ((sbsec->flags & SE_MNTMASK) && !opts)
727 goto out_double_mount;
728 rc = 0;
729 goto out;
730 }
731
732 if (strcmp(sb->s_type->name, "proc") == 0)
733 sbsec->flags |= SE_SBPROC | SE_SBGENFS;
734
735 if (!strcmp(sb->s_type->name, "debugfs") ||
736 !strcmp(sb->s_type->name, "tracefs") ||
737 !strcmp(sb->s_type->name, "binder") ||
738 !strcmp(sb->s_type->name, "bpf") ||
739 !strcmp(sb->s_type->name, "pstore") ||
740 !strcmp(sb->s_type->name, "securityfs") ||
741 // Android: remove functionfs policycap check due to
742 // ABI breakage with policycap array.
743 !strcmp(sb->s_type->name, "functionfs"))
744 sbsec->flags |= SE_SBGENFS;
745
746 if (!strcmp(sb->s_type->name, "sysfs") ||
747 !strcmp(sb->s_type->name, "cgroup") ||
748 !strcmp(sb->s_type->name, "cgroup2"))
749 sbsec->flags |= SE_SBGENFS | SE_SBGENFS_XATTR;
750
751 if (!sbsec->behavior) {
752 /*
753 * Determine the labeling behavior to use for this
754 * filesystem type.
755 */
756 rc = security_fs_use(sb);
757 if (rc) {
758 pr_warn("%s: security_fs_use(%s) returned %d\n",
759 __func__, sb->s_type->name, rc);
760 goto out;
761 }
762 }
763
764 /*
765 * If this is a user namespace mount and the filesystem type is not
766 * explicitly whitelisted, then no contexts are allowed on the command
767 * line and security labels must be ignored.
768 */
769 if (sb->s_user_ns != &init_user_ns &&
770 strcmp(sb->s_type->name, "tmpfs") &&
771 strcmp(sb->s_type->name, "ramfs") &&
772 strcmp(sb->s_type->name, "devpts") &&
773 strcmp(sb->s_type->name, "overlay")) {
774 if (context_sid || fscontext_sid || rootcontext_sid ||
775 defcontext_sid) {
776 rc = -EACCES;
777 goto out;
778 }
779 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
780 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
781 rc = security_transition_sid(current_sid(),
782 current_sid(),
783 SECCLASS_FILE, NULL,
784 &sbsec->mntpoint_sid);
785 if (rc)
786 goto out;
787 }
788 goto out_set_opts;
789 }
790
791 /* sets the context of the superblock for the fs being mounted. */
792 if (fscontext_sid) {
793 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
794 if (rc)
795 goto out;
796
797 sbsec->sid = fscontext_sid;
798 }
799
800 /*
801 * Switch to using mount point labeling behavior.
802 * sets the label used on all file below the mountpoint, and will set
803 * the superblock context if not already set.
804 */
805 if (sbsec->flags & SE_SBNATIVE) {
806 /*
807 * This means we are initializing a superblock that has been
808 * mounted before the SELinux was initialized and the
809 * filesystem requested native labeling. We had already
810 * returned SECURITY_LSM_NATIVE_LABELS in *set_kern_flags
811 * in the original mount attempt, so now we just need to set
812 * the SECURITY_FS_USE_NATIVE behavior.
813 */
814 sbsec->behavior = SECURITY_FS_USE_NATIVE;
815 } else if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
816 sbsec->behavior = SECURITY_FS_USE_NATIVE;
817 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
818 }
819
820 if (context_sid) {
821 if (!fscontext_sid) {
822 rc = may_context_mount_sb_relabel(context_sid, sbsec,
823 cred);
824 if (rc)
825 goto out;
826 sbsec->sid = context_sid;
827 } else {
828 rc = may_context_mount_inode_relabel(context_sid, sbsec,
829 cred);
830 if (rc)
831 goto out;
832 }
833 if (!rootcontext_sid)
834 rootcontext_sid = context_sid;
835
836 sbsec->mntpoint_sid = context_sid;
837 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
838 }
839
840 if (rootcontext_sid) {
841 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
842 cred);
843 if (rc)
844 goto out;
845
846 root_isec->sid = rootcontext_sid;
847 root_isec->initialized = LABEL_INITIALIZED;
848 }
849
850 if (defcontext_sid) {
851 if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
852 sbsec->behavior != SECURITY_FS_USE_NATIVE) {
853 rc = -EINVAL;
854 pr_warn("SELinux: defcontext option is "
855 "invalid for this filesystem type\n");
856 goto out;
857 }
858
859 if (defcontext_sid != sbsec->def_sid) {
860 rc = may_context_mount_inode_relabel(defcontext_sid,
861 sbsec, cred);
862 if (rc)
863 goto out;
864 }
865
866 sbsec->def_sid = defcontext_sid;
867 }
868
869 out_set_opts:
870 rc = sb_finish_set_opts(sb);
871 out:
872 mutex_unlock(&sbsec->lock);
873 return rc;
874 out_double_mount:
875 rc = -EINVAL;
876 pr_warn("SELinux: mount invalid. Same superblock, different "
877 "security settings for (dev %s, type %s)\n", sb->s_id,
878 sb->s_type->name);
879 goto out;
880 }
881
selinux_cmp_sb_context(const struct super_block * oldsb,const struct super_block * newsb)882 static int selinux_cmp_sb_context(const struct super_block *oldsb,
883 const struct super_block *newsb)
884 {
885 struct superblock_security_struct *old = selinux_superblock(oldsb);
886 struct superblock_security_struct *new = selinux_superblock(newsb);
887 char oldflags = old->flags & SE_MNTMASK;
888 char newflags = new->flags & SE_MNTMASK;
889
890 if (oldflags != newflags)
891 goto mismatch;
892 if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
893 goto mismatch;
894 if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
895 goto mismatch;
896 if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
897 goto mismatch;
898 if (oldflags & ROOTCONTEXT_MNT) {
899 struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root);
900 struct inode_security_struct *newroot = backing_inode_security(newsb->s_root);
901 if (oldroot->sid != newroot->sid)
902 goto mismatch;
903 }
904 return 0;
905 mismatch:
906 pr_warn("SELinux: mount invalid. Same superblock, "
907 "different security settings for (dev %s, "
908 "type %s)\n", newsb->s_id, newsb->s_type->name);
909 return -EBUSY;
910 }
911
selinux_sb_clone_mnt_opts(const struct super_block * oldsb,struct super_block * newsb,unsigned long kern_flags,unsigned long * set_kern_flags)912 static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
913 struct super_block *newsb,
914 unsigned long kern_flags,
915 unsigned long *set_kern_flags)
916 {
917 int rc = 0;
918 const struct superblock_security_struct *oldsbsec =
919 selinux_superblock(oldsb);
920 struct superblock_security_struct *newsbsec = selinux_superblock(newsb);
921
922 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT);
923 int set_context = (oldsbsec->flags & CONTEXT_MNT);
924 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT);
925
926 /*
927 * Specifying internal flags without providing a place to
928 * place the results is not allowed.
929 */
930 if (kern_flags && !set_kern_flags)
931 return -EINVAL;
932
933 mutex_lock(&newsbsec->lock);
934
935 /*
936 * if the parent was able to be mounted it clearly had no special lsm
937 * mount options. thus we can safely deal with this superblock later
938 */
939 if (!selinux_initialized()) {
940 if (kern_flags & SECURITY_LSM_NATIVE_LABELS) {
941 newsbsec->flags |= SE_SBNATIVE;
942 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
943 }
944 goto out;
945 }
946
947 /* how can we clone if the old one wasn't set up?? */
948 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
949
950 /* if fs is reusing a sb, make sure that the contexts match */
951 if (newsbsec->flags & SE_SBINITIALIZED) {
952 mutex_unlock(&newsbsec->lock);
953 if ((kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context)
954 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
955 return selinux_cmp_sb_context(oldsb, newsb);
956 }
957
958 newsbsec->flags = oldsbsec->flags;
959
960 newsbsec->sid = oldsbsec->sid;
961 newsbsec->def_sid = oldsbsec->def_sid;
962 newsbsec->behavior = oldsbsec->behavior;
963
964 if (newsbsec->behavior == SECURITY_FS_USE_NATIVE &&
965 !(kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) {
966 rc = security_fs_use(newsb);
967 if (rc)
968 goto out;
969 }
970
971 if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !set_context) {
972 newsbsec->behavior = SECURITY_FS_USE_NATIVE;
973 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
974 }
975
976 if (set_context) {
977 u32 sid = oldsbsec->mntpoint_sid;
978
979 if (!set_fscontext)
980 newsbsec->sid = sid;
981 if (!set_rootcontext) {
982 struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
983 newisec->sid = sid;
984 }
985 newsbsec->mntpoint_sid = sid;
986 }
987 if (set_rootcontext) {
988 const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root);
989 struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
990
991 newisec->sid = oldisec->sid;
992 }
993
994 sb_finish_set_opts(newsb);
995 out:
996 mutex_unlock(&newsbsec->lock);
997 return rc;
998 }
999
1000 /*
1001 * NOTE: the caller is responsible for freeing the memory even if on error.
1002 */
selinux_add_opt(int token,const char * s,void ** mnt_opts)1003 static int selinux_add_opt(int token, const char *s, void **mnt_opts)
1004 {
1005 struct selinux_mnt_opts *opts = *mnt_opts;
1006 u32 *dst_sid;
1007 int rc;
1008
1009 if (token == Opt_seclabel)
1010 /* eaten and completely ignored */
1011 return 0;
1012 if (!s)
1013 return -EINVAL;
1014
1015 if (!selinux_initialized()) {
1016 pr_warn("SELinux: Unable to set superblock options before the security server is initialized\n");
1017 return -EINVAL;
1018 }
1019
1020 if (!opts) {
1021 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1022 if (!opts)
1023 return -ENOMEM;
1024 *mnt_opts = opts;
1025 }
1026
1027 switch (token) {
1028 case Opt_context:
1029 if (opts->context_sid || opts->defcontext_sid)
1030 goto err;
1031 dst_sid = &opts->context_sid;
1032 break;
1033 case Opt_fscontext:
1034 if (opts->fscontext_sid)
1035 goto err;
1036 dst_sid = &opts->fscontext_sid;
1037 break;
1038 case Opt_rootcontext:
1039 if (opts->rootcontext_sid)
1040 goto err;
1041 dst_sid = &opts->rootcontext_sid;
1042 break;
1043 case Opt_defcontext:
1044 if (opts->context_sid || opts->defcontext_sid)
1045 goto err;
1046 dst_sid = &opts->defcontext_sid;
1047 break;
1048 default:
1049 WARN_ON(1);
1050 return -EINVAL;
1051 }
1052 rc = security_context_str_to_sid(s, dst_sid, GFP_KERNEL);
1053 if (rc)
1054 pr_warn("SELinux: security_context_str_to_sid (%s) failed with errno=%d\n",
1055 s, rc);
1056 return rc;
1057
1058 err:
1059 pr_warn(SEL_MOUNT_FAIL_MSG);
1060 return -EINVAL;
1061 }
1062
show_sid(struct seq_file * m,u32 sid)1063 static int show_sid(struct seq_file *m, u32 sid)
1064 {
1065 char *context = NULL;
1066 u32 len;
1067 int rc;
1068
1069 rc = security_sid_to_context(sid, &context, &len);
1070 if (!rc) {
1071 bool has_comma = strchr(context, ',');
1072
1073 seq_putc(m, '=');
1074 if (has_comma)
1075 seq_putc(m, '\"');
1076 seq_escape(m, context, "\"\n\\");
1077 if (has_comma)
1078 seq_putc(m, '\"');
1079 }
1080 kfree(context);
1081 return rc;
1082 }
1083
selinux_sb_show_options(struct seq_file * m,struct super_block * sb)1084 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1085 {
1086 struct superblock_security_struct *sbsec = selinux_superblock(sb);
1087 int rc;
1088
1089 if (!(sbsec->flags & SE_SBINITIALIZED))
1090 return 0;
1091
1092 if (!selinux_initialized())
1093 return 0;
1094
1095 if (sbsec->flags & FSCONTEXT_MNT) {
1096 seq_putc(m, ',');
1097 seq_puts(m, FSCONTEXT_STR);
1098 rc = show_sid(m, sbsec->sid);
1099 if (rc)
1100 return rc;
1101 }
1102 if (sbsec->flags & CONTEXT_MNT) {
1103 seq_putc(m, ',');
1104 seq_puts(m, CONTEXT_STR);
1105 rc = show_sid(m, sbsec->mntpoint_sid);
1106 if (rc)
1107 return rc;
1108 }
1109 if (sbsec->flags & DEFCONTEXT_MNT) {
1110 seq_putc(m, ',');
1111 seq_puts(m, DEFCONTEXT_STR);
1112 rc = show_sid(m, sbsec->def_sid);
1113 if (rc)
1114 return rc;
1115 }
1116 if (sbsec->flags & ROOTCONTEXT_MNT) {
1117 struct dentry *root = sb->s_root;
1118 struct inode_security_struct *isec = backing_inode_security(root);
1119 seq_putc(m, ',');
1120 seq_puts(m, ROOTCONTEXT_STR);
1121 rc = show_sid(m, isec->sid);
1122 if (rc)
1123 return rc;
1124 }
1125 if (sbsec->flags & SBLABEL_MNT) {
1126 seq_putc(m, ',');
1127 seq_puts(m, SECLABEL_STR);
1128 }
1129 return 0;
1130 }
1131
inode_mode_to_security_class(umode_t mode)1132 static inline u16 inode_mode_to_security_class(umode_t mode)
1133 {
1134 switch (mode & S_IFMT) {
1135 case S_IFSOCK:
1136 return SECCLASS_SOCK_FILE;
1137 case S_IFLNK:
1138 return SECCLASS_LNK_FILE;
1139 case S_IFREG:
1140 return SECCLASS_FILE;
1141 case S_IFBLK:
1142 return SECCLASS_BLK_FILE;
1143 case S_IFDIR:
1144 return SECCLASS_DIR;
1145 case S_IFCHR:
1146 return SECCLASS_CHR_FILE;
1147 case S_IFIFO:
1148 return SECCLASS_FIFO_FILE;
1149
1150 }
1151
1152 return SECCLASS_FILE;
1153 }
1154
default_protocol_stream(int protocol)1155 static inline int default_protocol_stream(int protocol)
1156 {
1157 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP ||
1158 protocol == IPPROTO_MPTCP);
1159 }
1160
default_protocol_dgram(int protocol)1161 static inline int default_protocol_dgram(int protocol)
1162 {
1163 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1164 }
1165
socket_type_to_security_class(int family,int type,int protocol)1166 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1167 {
1168 bool extsockclass = selinux_policycap_extsockclass();
1169
1170 switch (family) {
1171 case PF_UNIX:
1172 switch (type) {
1173 case SOCK_STREAM:
1174 case SOCK_SEQPACKET:
1175 return SECCLASS_UNIX_STREAM_SOCKET;
1176 case SOCK_DGRAM:
1177 case SOCK_RAW:
1178 return SECCLASS_UNIX_DGRAM_SOCKET;
1179 }
1180 break;
1181 case PF_INET:
1182 case PF_INET6:
1183 switch (type) {
1184 case SOCK_STREAM:
1185 case SOCK_SEQPACKET:
1186 if (default_protocol_stream(protocol))
1187 return SECCLASS_TCP_SOCKET;
1188 else if (extsockclass && protocol == IPPROTO_SCTP)
1189 return SECCLASS_SCTP_SOCKET;
1190 else
1191 return SECCLASS_RAWIP_SOCKET;
1192 case SOCK_DGRAM:
1193 if (default_protocol_dgram(protocol))
1194 return SECCLASS_UDP_SOCKET;
1195 else if (extsockclass && (protocol == IPPROTO_ICMP ||
1196 protocol == IPPROTO_ICMPV6))
1197 return SECCLASS_ICMP_SOCKET;
1198 else
1199 return SECCLASS_RAWIP_SOCKET;
1200 case SOCK_DCCP:
1201 return SECCLASS_DCCP_SOCKET;
1202 default:
1203 return SECCLASS_RAWIP_SOCKET;
1204 }
1205 break;
1206 case PF_NETLINK:
1207 switch (protocol) {
1208 case NETLINK_ROUTE:
1209 return SECCLASS_NETLINK_ROUTE_SOCKET;
1210 case NETLINK_SOCK_DIAG:
1211 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1212 case NETLINK_NFLOG:
1213 return SECCLASS_NETLINK_NFLOG_SOCKET;
1214 case NETLINK_XFRM:
1215 return SECCLASS_NETLINK_XFRM_SOCKET;
1216 case NETLINK_SELINUX:
1217 return SECCLASS_NETLINK_SELINUX_SOCKET;
1218 case NETLINK_ISCSI:
1219 return SECCLASS_NETLINK_ISCSI_SOCKET;
1220 case NETLINK_AUDIT:
1221 return SECCLASS_NETLINK_AUDIT_SOCKET;
1222 case NETLINK_FIB_LOOKUP:
1223 return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET;
1224 case NETLINK_CONNECTOR:
1225 return SECCLASS_NETLINK_CONNECTOR_SOCKET;
1226 case NETLINK_NETFILTER:
1227 return SECCLASS_NETLINK_NETFILTER_SOCKET;
1228 case NETLINK_DNRTMSG:
1229 return SECCLASS_NETLINK_DNRT_SOCKET;
1230 case NETLINK_KOBJECT_UEVENT:
1231 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1232 case NETLINK_GENERIC:
1233 return SECCLASS_NETLINK_GENERIC_SOCKET;
1234 case NETLINK_SCSITRANSPORT:
1235 return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET;
1236 case NETLINK_RDMA:
1237 return SECCLASS_NETLINK_RDMA_SOCKET;
1238 case NETLINK_CRYPTO:
1239 return SECCLASS_NETLINK_CRYPTO_SOCKET;
1240 default:
1241 return SECCLASS_NETLINK_SOCKET;
1242 }
1243 case PF_PACKET:
1244 return SECCLASS_PACKET_SOCKET;
1245 case PF_KEY:
1246 return SECCLASS_KEY_SOCKET;
1247 case PF_APPLETALK:
1248 return SECCLASS_APPLETALK_SOCKET;
1249 }
1250
1251 if (extsockclass) {
1252 switch (family) {
1253 case PF_AX25:
1254 return SECCLASS_AX25_SOCKET;
1255 case PF_IPX:
1256 return SECCLASS_IPX_SOCKET;
1257 case PF_NETROM:
1258 return SECCLASS_NETROM_SOCKET;
1259 case PF_ATMPVC:
1260 return SECCLASS_ATMPVC_SOCKET;
1261 case PF_X25:
1262 return SECCLASS_X25_SOCKET;
1263 case PF_ROSE:
1264 return SECCLASS_ROSE_SOCKET;
1265 case PF_DECnet:
1266 return SECCLASS_DECNET_SOCKET;
1267 case PF_ATMSVC:
1268 return SECCLASS_ATMSVC_SOCKET;
1269 case PF_RDS:
1270 return SECCLASS_RDS_SOCKET;
1271 case PF_IRDA:
1272 return SECCLASS_IRDA_SOCKET;
1273 case PF_PPPOX:
1274 return SECCLASS_PPPOX_SOCKET;
1275 case PF_LLC:
1276 return SECCLASS_LLC_SOCKET;
1277 case PF_CAN:
1278 return SECCLASS_CAN_SOCKET;
1279 case PF_TIPC:
1280 return SECCLASS_TIPC_SOCKET;
1281 case PF_BLUETOOTH:
1282 return SECCLASS_BLUETOOTH_SOCKET;
1283 case PF_IUCV:
1284 return SECCLASS_IUCV_SOCKET;
1285 case PF_RXRPC:
1286 return SECCLASS_RXRPC_SOCKET;
1287 case PF_ISDN:
1288 return SECCLASS_ISDN_SOCKET;
1289 case PF_PHONET:
1290 return SECCLASS_PHONET_SOCKET;
1291 case PF_IEEE802154:
1292 return SECCLASS_IEEE802154_SOCKET;
1293 case PF_CAIF:
1294 return SECCLASS_CAIF_SOCKET;
1295 case PF_ALG:
1296 return SECCLASS_ALG_SOCKET;
1297 case PF_NFC:
1298 return SECCLASS_NFC_SOCKET;
1299 case PF_VSOCK:
1300 return SECCLASS_VSOCK_SOCKET;
1301 case PF_KCM:
1302 return SECCLASS_KCM_SOCKET;
1303 case PF_QIPCRTR:
1304 return SECCLASS_QIPCRTR_SOCKET;
1305 case PF_SMC:
1306 return SECCLASS_SMC_SOCKET;
1307 case PF_XDP:
1308 return SECCLASS_XDP_SOCKET;
1309 case PF_MCTP:
1310 return SECCLASS_MCTP_SOCKET;
1311 #if PF_MAX > 46
1312 #error New address family defined, please update this function.
1313 #endif
1314 }
1315 }
1316
1317 return SECCLASS_SOCKET;
1318 }
1319
selinux_genfs_get_sid(struct dentry * dentry,u16 tclass,u16 flags,u32 * sid)1320 static int selinux_genfs_get_sid(struct dentry *dentry,
1321 u16 tclass,
1322 u16 flags,
1323 u32 *sid)
1324 {
1325 int rc;
1326 struct super_block *sb = dentry->d_sb;
1327 char *buffer, *path;
1328
1329 buffer = (char *)__get_free_page(GFP_KERNEL);
1330 if (!buffer)
1331 return -ENOMEM;
1332
1333 path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1334 if (IS_ERR(path))
1335 rc = PTR_ERR(path);
1336 else {
1337 if (flags & SE_SBPROC) {
1338 /* each process gets a /proc/PID/ entry. Strip off the
1339 * PID part to get a valid selinux labeling.
1340 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1341 while (path[1] >= '0' && path[1] <= '9') {
1342 path[1] = '/';
1343 path++;
1344 }
1345 }
1346 rc = security_genfs_sid(sb->s_type->name,
1347 path, tclass, sid);
1348 if (rc == -ENOENT) {
1349 /* No match in policy, mark as unlabeled. */
1350 *sid = SECINITSID_UNLABELED;
1351 rc = 0;
1352 }
1353 }
1354 free_page((unsigned long)buffer);
1355 return rc;
1356 }
1357
inode_doinit_use_xattr(struct inode * inode,struct dentry * dentry,u32 def_sid,u32 * sid)1358 static int inode_doinit_use_xattr(struct inode *inode, struct dentry *dentry,
1359 u32 def_sid, u32 *sid)
1360 {
1361 #define INITCONTEXTLEN 255
1362 char *context;
1363 unsigned int len;
1364 int rc;
1365
1366 len = INITCONTEXTLEN;
1367 context = kmalloc(len + 1, GFP_NOFS);
1368 if (!context)
1369 return -ENOMEM;
1370
1371 context[len] = '\0';
1372 rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
1373 if (rc == -ERANGE) {
1374 kfree(context);
1375
1376 /* Need a larger buffer. Query for the right size. */
1377 rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0);
1378 if (rc < 0)
1379 return rc;
1380
1381 len = rc;
1382 context = kmalloc(len + 1, GFP_NOFS);
1383 if (!context)
1384 return -ENOMEM;
1385
1386 context[len] = '\0';
1387 rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX,
1388 context, len);
1389 }
1390 if (rc < 0) {
1391 kfree(context);
1392 if (rc != -ENODATA) {
1393 pr_warn("SELinux: %s: getxattr returned %d for dev=%s ino=%ld\n",
1394 __func__, -rc, inode->i_sb->s_id, inode->i_ino);
1395 return rc;
1396 }
1397 *sid = def_sid;
1398 return 0;
1399 }
1400
1401 rc = security_context_to_sid_default(context, rc, sid,
1402 def_sid, GFP_NOFS);
1403 if (rc) {
1404 char *dev = inode->i_sb->s_id;
1405 unsigned long ino = inode->i_ino;
1406
1407 if (rc == -EINVAL) {
1408 pr_notice_ratelimited("SELinux: inode=%lu on dev=%s was found to have an invalid context=%s. This indicates you may need to relabel the inode or the filesystem in question.\n",
1409 ino, dev, context);
1410 } else {
1411 pr_warn("SELinux: %s: context_to_sid(%s) returned %d for dev=%s ino=%ld\n",
1412 __func__, context, -rc, dev, ino);
1413 }
1414 }
1415 kfree(context);
1416 return 0;
1417 }
1418
1419 /* The inode's security attributes must be initialized before first use. */
inode_doinit_with_dentry(struct inode * inode,struct dentry * opt_dentry)1420 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1421 {
1422 struct superblock_security_struct *sbsec = NULL;
1423 struct inode_security_struct *isec = selinux_inode(inode);
1424 u32 task_sid, sid = 0;
1425 u16 sclass;
1426 struct dentry *dentry;
1427 int rc = 0;
1428
1429 if (isec->initialized == LABEL_INITIALIZED)
1430 return 0;
1431
1432 spin_lock(&isec->lock);
1433 if (isec->initialized == LABEL_INITIALIZED)
1434 goto out_unlock;
1435
1436 if (isec->sclass == SECCLASS_FILE)
1437 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1438
1439 sbsec = selinux_superblock(inode->i_sb);
1440 if (!(sbsec->flags & SE_SBINITIALIZED)) {
1441 /* Defer initialization until selinux_complete_init,
1442 after the initial policy is loaded and the security
1443 server is ready to handle calls. */
1444 spin_lock(&sbsec->isec_lock);
1445 if (list_empty(&isec->list))
1446 list_add(&isec->list, &sbsec->isec_head);
1447 spin_unlock(&sbsec->isec_lock);
1448 goto out_unlock;
1449 }
1450
1451 sclass = isec->sclass;
1452 task_sid = isec->task_sid;
1453 sid = isec->sid;
1454 isec->initialized = LABEL_PENDING;
1455 spin_unlock(&isec->lock);
1456
1457 switch (sbsec->behavior) {
1458 /*
1459 * In case of SECURITY_FS_USE_NATIVE we need to re-fetch the labels
1460 * via xattr when called from delayed_superblock_init().
1461 */
1462 case SECURITY_FS_USE_NATIVE:
1463 case SECURITY_FS_USE_XATTR:
1464 if (!(inode->i_opflags & IOP_XATTR)) {
1465 sid = sbsec->def_sid;
1466 break;
1467 }
1468 /* Need a dentry, since the xattr API requires one.
1469 Life would be simpler if we could just pass the inode. */
1470 if (opt_dentry) {
1471 /* Called from d_instantiate or d_splice_alias. */
1472 dentry = dget(opt_dentry);
1473 } else {
1474 /*
1475 * Called from selinux_complete_init, try to find a dentry.
1476 * Some filesystems really want a connected one, so try
1477 * that first. We could split SECURITY_FS_USE_XATTR in
1478 * two, depending upon that...
1479 */
1480 dentry = d_find_alias(inode);
1481 if (!dentry)
1482 dentry = d_find_any_alias(inode);
1483 }
1484 if (!dentry) {
1485 /*
1486 * this is can be hit on boot when a file is accessed
1487 * before the policy is loaded. When we load policy we
1488 * may find inodes that have no dentry on the
1489 * sbsec->isec_head list. No reason to complain as these
1490 * will get fixed up the next time we go through
1491 * inode_doinit with a dentry, before these inodes could
1492 * be used again by userspace.
1493 */
1494 goto out_invalid;
1495 }
1496
1497 rc = inode_doinit_use_xattr(inode, dentry, sbsec->def_sid,
1498 &sid);
1499 dput(dentry);
1500 if (rc)
1501 goto out;
1502 break;
1503 case SECURITY_FS_USE_TASK:
1504 sid = task_sid;
1505 break;
1506 case SECURITY_FS_USE_TRANS:
1507 /* Default to the fs SID. */
1508 sid = sbsec->sid;
1509
1510 /* Try to obtain a transition SID. */
1511 rc = security_transition_sid(task_sid, sid,
1512 sclass, NULL, &sid);
1513 if (rc)
1514 goto out;
1515 break;
1516 case SECURITY_FS_USE_MNTPOINT:
1517 sid = sbsec->mntpoint_sid;
1518 break;
1519 default:
1520 /* Default to the fs superblock SID. */
1521 sid = sbsec->sid;
1522
1523 if ((sbsec->flags & SE_SBGENFS) &&
1524 (!S_ISLNK(inode->i_mode) ||
1525 selinux_policycap_genfs_seclabel_symlinks())) {
1526 /* We must have a dentry to determine the label on
1527 * procfs inodes */
1528 if (opt_dentry) {
1529 /* Called from d_instantiate or
1530 * d_splice_alias. */
1531 dentry = dget(opt_dentry);
1532 } else {
1533 /* Called from selinux_complete_init, try to
1534 * find a dentry. Some filesystems really want
1535 * a connected one, so try that first.
1536 */
1537 dentry = d_find_alias(inode);
1538 if (!dentry)
1539 dentry = d_find_any_alias(inode);
1540 }
1541 /*
1542 * This can be hit on boot when a file is accessed
1543 * before the policy is loaded. When we load policy we
1544 * may find inodes that have no dentry on the
1545 * sbsec->isec_head list. No reason to complain as
1546 * these will get fixed up the next time we go through
1547 * inode_doinit() with a dentry, before these inodes
1548 * could be used again by userspace.
1549 */
1550 if (!dentry)
1551 goto out_invalid;
1552 rc = selinux_genfs_get_sid(dentry, sclass,
1553 sbsec->flags, &sid);
1554 if (rc) {
1555 dput(dentry);
1556 goto out;
1557 }
1558
1559 if ((sbsec->flags & SE_SBGENFS_XATTR) &&
1560 (inode->i_opflags & IOP_XATTR)) {
1561 rc = inode_doinit_use_xattr(inode, dentry,
1562 sid, &sid);
1563 if (rc) {
1564 dput(dentry);
1565 goto out;
1566 }
1567 }
1568 dput(dentry);
1569 }
1570 break;
1571 }
1572
1573 out:
1574 spin_lock(&isec->lock);
1575 if (isec->initialized == LABEL_PENDING) {
1576 if (rc) {
1577 isec->initialized = LABEL_INVALID;
1578 goto out_unlock;
1579 }
1580 isec->initialized = LABEL_INITIALIZED;
1581 isec->sid = sid;
1582 }
1583
1584 out_unlock:
1585 spin_unlock(&isec->lock);
1586 return rc;
1587
1588 out_invalid:
1589 spin_lock(&isec->lock);
1590 if (isec->initialized == LABEL_PENDING) {
1591 isec->initialized = LABEL_INVALID;
1592 isec->sid = sid;
1593 }
1594 spin_unlock(&isec->lock);
1595 return 0;
1596 }
1597
1598 /* Convert a Linux signal to an access vector. */
signal_to_av(int sig)1599 static inline u32 signal_to_av(int sig)
1600 {
1601 u32 perm = 0;
1602
1603 switch (sig) {
1604 case SIGCHLD:
1605 /* Commonly granted from child to parent. */
1606 perm = PROCESS__SIGCHLD;
1607 break;
1608 case SIGKILL:
1609 /* Cannot be caught or ignored */
1610 perm = PROCESS__SIGKILL;
1611 break;
1612 case SIGSTOP:
1613 /* Cannot be caught or ignored */
1614 perm = PROCESS__SIGSTOP;
1615 break;
1616 default:
1617 /* All other signals. */
1618 perm = PROCESS__SIGNAL;
1619 break;
1620 }
1621
1622 return perm;
1623 }
1624
1625 #if CAP_LAST_CAP > 63
1626 #error Fix SELinux to handle capabilities > 63.
1627 #endif
1628
1629 /* Check whether a task is allowed to use a capability. */
cred_has_capability(const struct cred * cred,int cap,unsigned int opts,bool initns)1630 static int cred_has_capability(const struct cred *cred,
1631 int cap, unsigned int opts, bool initns)
1632 {
1633 struct common_audit_data ad;
1634 struct av_decision avd;
1635 u16 sclass;
1636 u32 sid = cred_sid(cred);
1637 u32 av = CAP_TO_MASK(cap);
1638 int rc;
1639
1640 ad.type = LSM_AUDIT_DATA_CAP;
1641 ad.u.cap = cap;
1642
1643 switch (CAP_TO_INDEX(cap)) {
1644 case 0:
1645 sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS;
1646 break;
1647 case 1:
1648 sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS;
1649 break;
1650 default:
1651 pr_err("SELinux: out of range capability %d\n", cap);
1652 BUG();
1653 return -EINVAL;
1654 }
1655
1656 rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1657 if (!(opts & CAP_OPT_NOAUDIT)) {
1658 int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
1659 if (rc2)
1660 return rc2;
1661 }
1662 return rc;
1663 }
1664
1665 /* Check whether a task has a particular permission to an inode.
1666 The 'adp' parameter is optional and allows other audit
1667 data to be passed (e.g. the dentry). */
inode_has_perm(const struct cred * cred,struct inode * inode,u32 perms,struct common_audit_data * adp)1668 static int inode_has_perm(const struct cred *cred,
1669 struct inode *inode,
1670 u32 perms,
1671 struct common_audit_data *adp)
1672 {
1673 struct inode_security_struct *isec;
1674 u32 sid;
1675
1676 if (unlikely(IS_PRIVATE(inode)))
1677 return 0;
1678
1679 sid = cred_sid(cred);
1680 isec = selinux_inode(inode);
1681
1682 return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
1683 }
1684
1685 /* Same as inode_has_perm, but pass explicit audit data containing
1686 the dentry to help the auditing code to more easily generate the
1687 pathname if needed. */
dentry_has_perm(const struct cred * cred,struct dentry * dentry,u32 av)1688 static inline int dentry_has_perm(const struct cred *cred,
1689 struct dentry *dentry,
1690 u32 av)
1691 {
1692 struct inode *inode = d_backing_inode(dentry);
1693 struct common_audit_data ad;
1694
1695 ad.type = LSM_AUDIT_DATA_DENTRY;
1696 ad.u.dentry = dentry;
1697 __inode_security_revalidate(inode, dentry, true);
1698 return inode_has_perm(cred, inode, av, &ad);
1699 }
1700
1701 /* Same as inode_has_perm, but pass explicit audit data containing
1702 the path to help the auditing code to more easily generate the
1703 pathname if needed. */
path_has_perm(const struct cred * cred,const struct path * path,u32 av)1704 static inline int path_has_perm(const struct cred *cred,
1705 const struct path *path,
1706 u32 av)
1707 {
1708 struct inode *inode = d_backing_inode(path->dentry);
1709 struct common_audit_data ad;
1710
1711 ad.type = LSM_AUDIT_DATA_PATH;
1712 ad.u.path = *path;
1713 __inode_security_revalidate(inode, path->dentry, true);
1714 return inode_has_perm(cred, inode, av, &ad);
1715 }
1716
1717 /* Same as path_has_perm, but uses the inode from the file struct. */
file_path_has_perm(const struct cred * cred,struct file * file,u32 av)1718 static inline int file_path_has_perm(const struct cred *cred,
1719 struct file *file,
1720 u32 av)
1721 {
1722 struct common_audit_data ad;
1723
1724 ad.type = LSM_AUDIT_DATA_FILE;
1725 ad.u.file = file;
1726 return inode_has_perm(cred, file_inode(file), av, &ad);
1727 }
1728
1729 #ifdef CONFIG_BPF_SYSCALL
1730 static int bpf_fd_pass(const struct file *file, u32 sid);
1731 #endif
1732
1733 /* Check whether a task can use an open file descriptor to
1734 access an inode in a given way. Check access to the
1735 descriptor itself, and then use dentry_has_perm to
1736 check a particular permission to the file.
1737 Access to the descriptor is implicitly granted if it
1738 has the same SID as the process. If av is zero, then
1739 access to the file is not checked, e.g. for cases
1740 where only the descriptor is affected like seek. */
file_has_perm(const struct cred * cred,struct file * file,u32 av)1741 static int file_has_perm(const struct cred *cred,
1742 struct file *file,
1743 u32 av)
1744 {
1745 struct file_security_struct *fsec = selinux_file(file);
1746 struct inode *inode = file_inode(file);
1747 struct common_audit_data ad;
1748 u32 sid = cred_sid(cred);
1749 int rc;
1750
1751 ad.type = LSM_AUDIT_DATA_FILE;
1752 ad.u.file = file;
1753
1754 if (sid != fsec->sid) {
1755 rc = avc_has_perm(sid, fsec->sid,
1756 SECCLASS_FD,
1757 FD__USE,
1758 &ad);
1759 if (rc)
1760 goto out;
1761 }
1762
1763 #ifdef CONFIG_BPF_SYSCALL
1764 rc = bpf_fd_pass(file, cred_sid(cred));
1765 if (rc)
1766 return rc;
1767 #endif
1768
1769 /* av is zero if only checking access to the descriptor. */
1770 rc = 0;
1771 if (av)
1772 rc = inode_has_perm(cred, inode, av, &ad);
1773
1774 out:
1775 return rc;
1776 }
1777
1778 /*
1779 * Determine the label for an inode that might be unioned.
1780 */
1781 static int
selinux_determine_inode_label(const struct task_security_struct * tsec,struct inode * dir,const struct qstr * name,u16 tclass,u32 * _new_isid)1782 selinux_determine_inode_label(const struct task_security_struct *tsec,
1783 struct inode *dir,
1784 const struct qstr *name, u16 tclass,
1785 u32 *_new_isid)
1786 {
1787 const struct superblock_security_struct *sbsec =
1788 selinux_superblock(dir->i_sb);
1789
1790 if ((sbsec->flags & SE_SBINITIALIZED) &&
1791 (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
1792 *_new_isid = sbsec->mntpoint_sid;
1793 } else if ((sbsec->flags & SBLABEL_MNT) &&
1794 tsec->create_sid) {
1795 *_new_isid = tsec->create_sid;
1796 } else {
1797 const struct inode_security_struct *dsec = inode_security(dir);
1798 return security_transition_sid(tsec->sid,
1799 dsec->sid, tclass,
1800 name, _new_isid);
1801 }
1802
1803 return 0;
1804 }
1805
1806 /* Check whether a task can create a file. */
may_create(struct inode * dir,struct dentry * dentry,u16 tclass)1807 static int may_create(struct inode *dir,
1808 struct dentry *dentry,
1809 u16 tclass)
1810 {
1811 const struct task_security_struct *tsec = selinux_cred(current_cred());
1812 struct inode_security_struct *dsec;
1813 struct superblock_security_struct *sbsec;
1814 u32 sid, newsid;
1815 struct common_audit_data ad;
1816 int rc;
1817
1818 dsec = inode_security(dir);
1819 sbsec = selinux_superblock(dir->i_sb);
1820
1821 sid = tsec->sid;
1822
1823 ad.type = LSM_AUDIT_DATA_DENTRY;
1824 ad.u.dentry = dentry;
1825
1826 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1827 DIR__ADD_NAME | DIR__SEARCH,
1828 &ad);
1829 if (rc)
1830 return rc;
1831
1832 rc = selinux_determine_inode_label(tsec, dir, &dentry->d_name, tclass,
1833 &newsid);
1834 if (rc)
1835 return rc;
1836
1837 rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1838 if (rc)
1839 return rc;
1840
1841 return avc_has_perm(newsid, sbsec->sid,
1842 SECCLASS_FILESYSTEM,
1843 FILESYSTEM__ASSOCIATE, &ad);
1844 }
1845
1846 #define MAY_LINK 0
1847 #define MAY_UNLINK 1
1848 #define MAY_RMDIR 2
1849
1850 /* Check whether a task can link, unlink, or rmdir a file/directory. */
may_link(struct inode * dir,struct dentry * dentry,int kind)1851 static int may_link(struct inode *dir,
1852 struct dentry *dentry,
1853 int kind)
1854
1855 {
1856 struct inode_security_struct *dsec, *isec;
1857 struct common_audit_data ad;
1858 u32 sid = current_sid();
1859 u32 av;
1860 int rc;
1861
1862 dsec = inode_security(dir);
1863 isec = backing_inode_security(dentry);
1864
1865 ad.type = LSM_AUDIT_DATA_DENTRY;
1866 ad.u.dentry = dentry;
1867
1868 av = DIR__SEARCH;
1869 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1870 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1871 if (rc)
1872 return rc;
1873
1874 switch (kind) {
1875 case MAY_LINK:
1876 av = FILE__LINK;
1877 break;
1878 case MAY_UNLINK:
1879 av = FILE__UNLINK;
1880 break;
1881 case MAY_RMDIR:
1882 av = DIR__RMDIR;
1883 break;
1884 default:
1885 pr_warn("SELinux: %s: unrecognized kind %d\n",
1886 __func__, kind);
1887 return 0;
1888 }
1889
1890 rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1891 return rc;
1892 }
1893
may_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry)1894 static inline int may_rename(struct inode *old_dir,
1895 struct dentry *old_dentry,
1896 struct inode *new_dir,
1897 struct dentry *new_dentry)
1898 {
1899 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1900 struct common_audit_data ad;
1901 u32 sid = current_sid();
1902 u32 av;
1903 int old_is_dir, new_is_dir;
1904 int rc;
1905
1906 old_dsec = inode_security(old_dir);
1907 old_isec = backing_inode_security(old_dentry);
1908 old_is_dir = d_is_dir(old_dentry);
1909 new_dsec = inode_security(new_dir);
1910
1911 ad.type = LSM_AUDIT_DATA_DENTRY;
1912
1913 ad.u.dentry = old_dentry;
1914 rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1915 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1916 if (rc)
1917 return rc;
1918 rc = avc_has_perm(sid, old_isec->sid,
1919 old_isec->sclass, FILE__RENAME, &ad);
1920 if (rc)
1921 return rc;
1922 if (old_is_dir && new_dir != old_dir) {
1923 rc = avc_has_perm(sid, old_isec->sid,
1924 old_isec->sclass, DIR__REPARENT, &ad);
1925 if (rc)
1926 return rc;
1927 }
1928
1929 ad.u.dentry = new_dentry;
1930 av = DIR__ADD_NAME | DIR__SEARCH;
1931 if (d_is_positive(new_dentry))
1932 av |= DIR__REMOVE_NAME;
1933 rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1934 if (rc)
1935 return rc;
1936 if (d_is_positive(new_dentry)) {
1937 new_isec = backing_inode_security(new_dentry);
1938 new_is_dir = d_is_dir(new_dentry);
1939 rc = avc_has_perm(sid, new_isec->sid,
1940 new_isec->sclass,
1941 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1942 if (rc)
1943 return rc;
1944 }
1945
1946 return 0;
1947 }
1948
1949 /* Check whether a task can perform a filesystem operation. */
superblock_has_perm(const struct cred * cred,const struct super_block * sb,u32 perms,struct common_audit_data * ad)1950 static int superblock_has_perm(const struct cred *cred,
1951 const struct super_block *sb,
1952 u32 perms,
1953 struct common_audit_data *ad)
1954 {
1955 struct superblock_security_struct *sbsec;
1956 u32 sid = cred_sid(cred);
1957
1958 sbsec = selinux_superblock(sb);
1959 return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1960 }
1961
1962 /* Convert a Linux mode and permission mask to an access vector. */
file_mask_to_av(int mode,int mask)1963 static inline u32 file_mask_to_av(int mode, int mask)
1964 {
1965 u32 av = 0;
1966
1967 if (!S_ISDIR(mode)) {
1968 if (mask & MAY_EXEC)
1969 av |= FILE__EXECUTE;
1970 if (mask & MAY_READ)
1971 av |= FILE__READ;
1972
1973 if (mask & MAY_APPEND)
1974 av |= FILE__APPEND;
1975 else if (mask & MAY_WRITE)
1976 av |= FILE__WRITE;
1977
1978 } else {
1979 if (mask & MAY_EXEC)
1980 av |= DIR__SEARCH;
1981 if (mask & MAY_WRITE)
1982 av |= DIR__WRITE;
1983 if (mask & MAY_READ)
1984 av |= DIR__READ;
1985 }
1986
1987 return av;
1988 }
1989
1990 /* Convert a Linux file to an access vector. */
file_to_av(const struct file * file)1991 static inline u32 file_to_av(const struct file *file)
1992 {
1993 u32 av = 0;
1994
1995 if (file->f_mode & FMODE_READ)
1996 av |= FILE__READ;
1997 if (file->f_mode & FMODE_WRITE) {
1998 if (file->f_flags & O_APPEND)
1999 av |= FILE__APPEND;
2000 else
2001 av |= FILE__WRITE;
2002 }
2003 if (!av) {
2004 /*
2005 * Special file opened with flags 3 for ioctl-only use.
2006 */
2007 av = FILE__IOCTL;
2008 }
2009
2010 return av;
2011 }
2012
2013 /*
2014 * Convert a file to an access vector and include the correct
2015 * open permission.
2016 */
open_file_to_av(struct file * file)2017 static inline u32 open_file_to_av(struct file *file)
2018 {
2019 u32 av = file_to_av(file);
2020 struct inode *inode = file_inode(file);
2021
2022 if (selinux_policycap_openperm() &&
2023 inode->i_sb->s_magic != SOCKFS_MAGIC)
2024 av |= FILE__OPEN;
2025
2026 return av;
2027 }
2028
2029 /* Hook functions begin here. */
2030
selinux_binder_set_context_mgr(const struct cred * mgr)2031 static int selinux_binder_set_context_mgr(const struct cred *mgr)
2032 {
2033 return avc_has_perm(current_sid(), cred_sid(mgr), SECCLASS_BINDER,
2034 BINDER__SET_CONTEXT_MGR, NULL);
2035 }
2036
selinux_binder_transaction(const struct cred * from,const struct cred * to)2037 static int selinux_binder_transaction(const struct cred *from,
2038 const struct cred *to)
2039 {
2040 u32 mysid = current_sid();
2041 u32 fromsid = cred_sid(from);
2042 u32 tosid = cred_sid(to);
2043 int rc;
2044
2045 if (mysid != fromsid) {
2046 rc = avc_has_perm(mysid, fromsid, SECCLASS_BINDER,
2047 BINDER__IMPERSONATE, NULL);
2048 if (rc)
2049 return rc;
2050 }
2051
2052 return avc_has_perm(fromsid, tosid,
2053 SECCLASS_BINDER, BINDER__CALL, NULL);
2054 }
2055
selinux_binder_transfer_binder(const struct cred * from,const struct cred * to)2056 static int selinux_binder_transfer_binder(const struct cred *from,
2057 const struct cred *to)
2058 {
2059 return avc_has_perm(cred_sid(from), cred_sid(to),
2060 SECCLASS_BINDER, BINDER__TRANSFER,
2061 NULL);
2062 }
2063
selinux_binder_transfer_file(const struct cred * from,const struct cred * to,const struct file * file)2064 static int selinux_binder_transfer_file(const struct cred *from,
2065 const struct cred *to,
2066 const struct file *file)
2067 {
2068 u32 sid = cred_sid(to);
2069 struct file_security_struct *fsec = selinux_file(file);
2070 struct dentry *dentry = file->f_path.dentry;
2071 struct inode_security_struct *isec;
2072 struct common_audit_data ad;
2073 int rc;
2074
2075 ad.type = LSM_AUDIT_DATA_PATH;
2076 ad.u.path = file->f_path;
2077
2078 if (sid != fsec->sid) {
2079 rc = avc_has_perm(sid, fsec->sid,
2080 SECCLASS_FD,
2081 FD__USE,
2082 &ad);
2083 if (rc)
2084 return rc;
2085 }
2086
2087 #ifdef CONFIG_BPF_SYSCALL
2088 rc = bpf_fd_pass(file, sid);
2089 if (rc)
2090 return rc;
2091 #endif
2092
2093 if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
2094 return 0;
2095
2096 isec = backing_inode_security(dentry);
2097 return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file),
2098 &ad);
2099 }
2100
selinux_ptrace_access_check(struct task_struct * child,unsigned int mode)2101 static int selinux_ptrace_access_check(struct task_struct *child,
2102 unsigned int mode)
2103 {
2104 u32 sid = current_sid();
2105 u32 csid = task_sid_obj(child);
2106
2107 if (mode & PTRACE_MODE_READ)
2108 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ,
2109 NULL);
2110
2111 return avc_has_perm(sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE,
2112 NULL);
2113 }
2114
selinux_ptrace_traceme(struct task_struct * parent)2115 static int selinux_ptrace_traceme(struct task_struct *parent)
2116 {
2117 return avc_has_perm(task_sid_obj(parent), task_sid_obj(current),
2118 SECCLASS_PROCESS, PROCESS__PTRACE, NULL);
2119 }
2120
selinux_capget(const struct task_struct * target,kernel_cap_t * effective,kernel_cap_t * inheritable,kernel_cap_t * permitted)2121 static int selinux_capget(const struct task_struct *target, kernel_cap_t *effective,
2122 kernel_cap_t *inheritable, kernel_cap_t *permitted)
2123 {
2124 return avc_has_perm(current_sid(), task_sid_obj(target),
2125 SECCLASS_PROCESS, PROCESS__GETCAP, NULL);
2126 }
2127
selinux_capset(struct cred * new,const struct cred * old,const kernel_cap_t * effective,const kernel_cap_t * inheritable,const kernel_cap_t * permitted)2128 static int selinux_capset(struct cred *new, const struct cred *old,
2129 const kernel_cap_t *effective,
2130 const kernel_cap_t *inheritable,
2131 const kernel_cap_t *permitted)
2132 {
2133 return avc_has_perm(cred_sid(old), cred_sid(new), SECCLASS_PROCESS,
2134 PROCESS__SETCAP, NULL);
2135 }
2136
2137 /*
2138 * (This comment used to live with the selinux_task_setuid hook,
2139 * which was removed).
2140 *
2141 * Since setuid only affects the current process, and since the SELinux
2142 * controls are not based on the Linux identity attributes, SELinux does not
2143 * need to control this operation. However, SELinux does control the use of
2144 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
2145 */
2146
selinux_capable(const struct cred * cred,struct user_namespace * ns,int cap,unsigned int opts)2147 static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
2148 int cap, unsigned int opts)
2149 {
2150 return cred_has_capability(cred, cap, opts, ns == &init_user_ns);
2151 }
2152
selinux_quotactl(int cmds,int type,int id,const struct super_block * sb)2153 static int selinux_quotactl(int cmds, int type, int id, const struct super_block *sb)
2154 {
2155 const struct cred *cred = current_cred();
2156 int rc = 0;
2157
2158 if (!sb)
2159 return 0;
2160
2161 switch (cmds) {
2162 case Q_SYNC:
2163 case Q_QUOTAON:
2164 case Q_QUOTAOFF:
2165 case Q_SETINFO:
2166 case Q_SETQUOTA:
2167 case Q_XQUOTAOFF:
2168 case Q_XQUOTAON:
2169 case Q_XSETQLIM:
2170 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
2171 break;
2172 case Q_GETFMT:
2173 case Q_GETINFO:
2174 case Q_GETQUOTA:
2175 case Q_XGETQUOTA:
2176 case Q_XGETQSTAT:
2177 case Q_XGETQSTATV:
2178 case Q_XGETNEXTQUOTA:
2179 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
2180 break;
2181 default:
2182 rc = 0; /* let the kernel handle invalid cmds */
2183 break;
2184 }
2185 return rc;
2186 }
2187
selinux_quota_on(struct dentry * dentry)2188 static int selinux_quota_on(struct dentry *dentry)
2189 {
2190 const struct cred *cred = current_cred();
2191
2192 return dentry_has_perm(cred, dentry, FILE__QUOTAON);
2193 }
2194
selinux_syslog(int type)2195 static int selinux_syslog(int type)
2196 {
2197 switch (type) {
2198 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */
2199 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */
2200 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
2201 SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL);
2202 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */
2203 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */
2204 /* Set level of messages printed to console */
2205 case SYSLOG_ACTION_CONSOLE_LEVEL:
2206 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
2207 SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE,
2208 NULL);
2209 }
2210 /* All other syslog types */
2211 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
2212 SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL);
2213 }
2214
2215 /*
2216 * Check permission for allocating a new virtual mapping. Returns
2217 * 0 if permission is granted, negative error code if not.
2218 *
2219 * Do not audit the selinux permission check, as this is applied to all
2220 * processes that allocate mappings.
2221 */
selinux_vm_enough_memory(struct mm_struct * mm,long pages)2222 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
2223 {
2224 return cred_has_capability(current_cred(), CAP_SYS_ADMIN,
2225 CAP_OPT_NOAUDIT, true);
2226 }
2227
2228 /* binprm security operations */
2229
ptrace_parent_sid(void)2230 static u32 ptrace_parent_sid(void)
2231 {
2232 u32 sid = 0;
2233 struct task_struct *tracer;
2234
2235 rcu_read_lock();
2236 tracer = ptrace_parent(current);
2237 if (tracer)
2238 sid = task_sid_obj(tracer);
2239 rcu_read_unlock();
2240
2241 return sid;
2242 }
2243
check_nnp_nosuid(const struct linux_binprm * bprm,const struct task_security_struct * old_tsec,const struct task_security_struct * new_tsec)2244 static int check_nnp_nosuid(const struct linux_binprm *bprm,
2245 const struct task_security_struct *old_tsec,
2246 const struct task_security_struct *new_tsec)
2247 {
2248 int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
2249 int nosuid = !mnt_may_suid(bprm->file->f_path.mnt);
2250 int rc;
2251 u32 av;
2252
2253 if (!nnp && !nosuid)
2254 return 0; /* neither NNP nor nosuid */
2255
2256 if (new_tsec->sid == old_tsec->sid)
2257 return 0; /* No change in credentials */
2258
2259 /*
2260 * If the policy enables the nnp_nosuid_transition policy capability,
2261 * then we permit transitions under NNP or nosuid if the
2262 * policy allows the corresponding permission between
2263 * the old and new contexts.
2264 */
2265 if (selinux_policycap_nnp_nosuid_transition()) {
2266 av = 0;
2267 if (nnp)
2268 av |= PROCESS2__NNP_TRANSITION;
2269 if (nosuid)
2270 av |= PROCESS2__NOSUID_TRANSITION;
2271 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2272 SECCLASS_PROCESS2, av, NULL);
2273 if (!rc)
2274 return 0;
2275 }
2276
2277 /*
2278 * We also permit NNP or nosuid transitions to bounded SIDs,
2279 * i.e. SIDs that are guaranteed to only be allowed a subset
2280 * of the permissions of the current SID.
2281 */
2282 rc = security_bounded_transition(old_tsec->sid,
2283 new_tsec->sid);
2284 if (!rc)
2285 return 0;
2286
2287 /*
2288 * On failure, preserve the errno values for NNP vs nosuid.
2289 * NNP: Operation not permitted for caller.
2290 * nosuid: Permission denied to file.
2291 */
2292 if (nnp)
2293 return -EPERM;
2294 return -EACCES;
2295 }
2296
selinux_bprm_creds_for_exec(struct linux_binprm * bprm)2297 static int selinux_bprm_creds_for_exec(struct linux_binprm *bprm)
2298 {
2299 const struct task_security_struct *old_tsec;
2300 struct task_security_struct *new_tsec;
2301 struct inode_security_struct *isec;
2302 struct common_audit_data ad;
2303 struct inode *inode = file_inode(bprm->file);
2304 int rc;
2305
2306 /* SELinux context only depends on initial program or script and not
2307 * the script interpreter */
2308
2309 old_tsec = selinux_cred(current_cred());
2310 new_tsec = selinux_cred(bprm->cred);
2311 isec = inode_security(inode);
2312
2313 /* Default to the current task SID. */
2314 new_tsec->sid = old_tsec->sid;
2315 new_tsec->osid = old_tsec->sid;
2316
2317 /* Reset fs, key, and sock SIDs on execve. */
2318 new_tsec->create_sid = 0;
2319 new_tsec->keycreate_sid = 0;
2320 new_tsec->sockcreate_sid = 0;
2321
2322 /*
2323 * Before policy is loaded, label any task outside kernel space
2324 * as SECINITSID_INIT, so that any userspace tasks surviving from
2325 * early boot end up with a label different from SECINITSID_KERNEL
2326 * (if the policy chooses to set SECINITSID_INIT != SECINITSID_KERNEL).
2327 */
2328 if (!selinux_initialized()) {
2329 new_tsec->sid = SECINITSID_INIT;
2330 /* also clear the exec_sid just in case */
2331 new_tsec->exec_sid = 0;
2332 return 0;
2333 }
2334
2335 if (old_tsec->exec_sid) {
2336 new_tsec->sid = old_tsec->exec_sid;
2337 /* Reset exec SID on execve. */
2338 new_tsec->exec_sid = 0;
2339
2340 /* Fail on NNP or nosuid if not an allowed transition. */
2341 rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2342 if (rc)
2343 return rc;
2344 } else {
2345 /* Check for a default transition on this program. */
2346 rc = security_transition_sid(old_tsec->sid,
2347 isec->sid, SECCLASS_PROCESS, NULL,
2348 &new_tsec->sid);
2349 if (rc)
2350 return rc;
2351
2352 /*
2353 * Fallback to old SID on NNP or nosuid if not an allowed
2354 * transition.
2355 */
2356 rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2357 if (rc)
2358 new_tsec->sid = old_tsec->sid;
2359 }
2360
2361 ad.type = LSM_AUDIT_DATA_FILE;
2362 ad.u.file = bprm->file;
2363
2364 if (new_tsec->sid == old_tsec->sid) {
2365 rc = avc_has_perm(old_tsec->sid, isec->sid,
2366 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2367 if (rc)
2368 return rc;
2369 } else {
2370 /* Check permissions for the transition. */
2371 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2372 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2373 if (rc)
2374 return rc;
2375
2376 rc = avc_has_perm(new_tsec->sid, isec->sid,
2377 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2378 if (rc)
2379 return rc;
2380
2381 /* Check for shared state */
2382 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2383 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2384 SECCLASS_PROCESS, PROCESS__SHARE,
2385 NULL);
2386 if (rc)
2387 return -EPERM;
2388 }
2389
2390 /* Make sure that anyone attempting to ptrace over a task that
2391 * changes its SID has the appropriate permit */
2392 if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
2393 u32 ptsid = ptrace_parent_sid();
2394 if (ptsid != 0) {
2395 rc = avc_has_perm(ptsid, new_tsec->sid,
2396 SECCLASS_PROCESS,
2397 PROCESS__PTRACE, NULL);
2398 if (rc)
2399 return -EPERM;
2400 }
2401 }
2402
2403 /* Clear any possibly unsafe personality bits on exec: */
2404 bprm->per_clear |= PER_CLEAR_ON_SETID;
2405
2406 /* Enable secure mode for SIDs transitions unless
2407 the noatsecure permission is granted between
2408 the two SIDs, i.e. ahp returns 0. */
2409 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2410 SECCLASS_PROCESS, PROCESS__NOATSECURE,
2411 NULL);
2412 bprm->secureexec |= !!rc;
2413 }
2414
2415 return 0;
2416 }
2417
match_file(const void * p,struct file * file,unsigned fd)2418 static int match_file(const void *p, struct file *file, unsigned fd)
2419 {
2420 return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0;
2421 }
2422
2423 /* Derived from fs/exec.c:flush_old_files. */
flush_unauthorized_files(const struct cred * cred,struct files_struct * files)2424 static inline void flush_unauthorized_files(const struct cred *cred,
2425 struct files_struct *files)
2426 {
2427 struct file *file, *devnull = NULL;
2428 struct tty_struct *tty;
2429 int drop_tty = 0;
2430 unsigned n;
2431
2432 tty = get_current_tty();
2433 if (tty) {
2434 spin_lock(&tty->files_lock);
2435 if (!list_empty(&tty->tty_files)) {
2436 struct tty_file_private *file_priv;
2437
2438 /* Revalidate access to controlling tty.
2439 Use file_path_has_perm on the tty path directly
2440 rather than using file_has_perm, as this particular
2441 open file may belong to another process and we are
2442 only interested in the inode-based check here. */
2443 file_priv = list_first_entry(&tty->tty_files,
2444 struct tty_file_private, list);
2445 file = file_priv->file;
2446 if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
2447 drop_tty = 1;
2448 }
2449 spin_unlock(&tty->files_lock);
2450 tty_kref_put(tty);
2451 }
2452 /* Reset controlling tty. */
2453 if (drop_tty)
2454 no_tty();
2455
2456 /* Revalidate access to inherited open files. */
2457 n = iterate_fd(files, 0, match_file, cred);
2458 if (!n) /* none found? */
2459 return;
2460
2461 devnull = dentry_open(&selinux_null, O_RDWR, cred);
2462 if (IS_ERR(devnull))
2463 devnull = NULL;
2464 /* replace all the matching ones with this */
2465 do {
2466 replace_fd(n - 1, devnull, 0);
2467 } while ((n = iterate_fd(files, n, match_file, cred)) != 0);
2468 if (devnull)
2469 fput(devnull);
2470 }
2471
2472 /*
2473 * Prepare a process for imminent new credential changes due to exec
2474 */
selinux_bprm_committing_creds(const struct linux_binprm * bprm)2475 static void selinux_bprm_committing_creds(const struct linux_binprm *bprm)
2476 {
2477 struct task_security_struct *new_tsec;
2478 struct rlimit *rlim, *initrlim;
2479 int rc, i;
2480
2481 new_tsec = selinux_cred(bprm->cred);
2482 if (new_tsec->sid == new_tsec->osid)
2483 return;
2484
2485 /* Close files for which the new task SID is not authorized. */
2486 flush_unauthorized_files(bprm->cred, current->files);
2487
2488 /* Always clear parent death signal on SID transitions. */
2489 current->pdeath_signal = 0;
2490
2491 /* Check whether the new SID can inherit resource limits from the old
2492 * SID. If not, reset all soft limits to the lower of the current
2493 * task's hard limit and the init task's soft limit.
2494 *
2495 * Note that the setting of hard limits (even to lower them) can be
2496 * controlled by the setrlimit check. The inclusion of the init task's
2497 * soft limit into the computation is to avoid resetting soft limits
2498 * higher than the default soft limit for cases where the default is
2499 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2500 */
2501 rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2502 PROCESS__RLIMITINH, NULL);
2503 if (rc) {
2504 /* protect against do_prlimit() */
2505 task_lock(current);
2506 for (i = 0; i < RLIM_NLIMITS; i++) {
2507 rlim = current->signal->rlim + i;
2508 initrlim = init_task.signal->rlim + i;
2509 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2510 }
2511 task_unlock(current);
2512 if (IS_ENABLED(CONFIG_POSIX_TIMERS))
2513 update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
2514 }
2515 }
2516
2517 /*
2518 * Clean up the process immediately after the installation of new credentials
2519 * due to exec
2520 */
selinux_bprm_committed_creds(const struct linux_binprm * bprm)2521 static void selinux_bprm_committed_creds(const struct linux_binprm *bprm)
2522 {
2523 const struct task_security_struct *tsec = selinux_cred(current_cred());
2524 u32 osid, sid;
2525 int rc;
2526
2527 osid = tsec->osid;
2528 sid = tsec->sid;
2529
2530 if (sid == osid)
2531 return;
2532
2533 /* Check whether the new SID can inherit signal state from the old SID.
2534 * If not, clear itimers to avoid subsequent signal generation and
2535 * flush and unblock signals.
2536 *
2537 * This must occur _after_ the task SID has been updated so that any
2538 * kill done after the flush will be checked against the new SID.
2539 */
2540 rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2541 if (rc) {
2542 clear_itimer();
2543
2544 spin_lock_irq(&unrcu_pointer(current->sighand)->siglock);
2545 if (!fatal_signal_pending(current)) {
2546 flush_sigqueue(¤t->pending);
2547 flush_sigqueue(¤t->signal->shared_pending);
2548 flush_signal_handlers(current, 1);
2549 sigemptyset(¤t->blocked);
2550 recalc_sigpending();
2551 }
2552 spin_unlock_irq(&unrcu_pointer(current->sighand)->siglock);
2553 }
2554
2555 /* Wake up the parent if it is waiting so that it can recheck
2556 * wait permission to the new task SID. */
2557 read_lock(&tasklist_lock);
2558 __wake_up_parent(current, unrcu_pointer(current->real_parent));
2559 read_unlock(&tasklist_lock);
2560 }
2561
2562 /* superblock security operations */
2563
selinux_sb_alloc_security(struct super_block * sb)2564 static int selinux_sb_alloc_security(struct super_block *sb)
2565 {
2566 struct superblock_security_struct *sbsec = selinux_superblock(sb);
2567
2568 mutex_init(&sbsec->lock);
2569 INIT_LIST_HEAD(&sbsec->isec_head);
2570 spin_lock_init(&sbsec->isec_lock);
2571 sbsec->sid = SECINITSID_UNLABELED;
2572 sbsec->def_sid = SECINITSID_FILE;
2573 sbsec->mntpoint_sid = SECINITSID_UNLABELED;
2574
2575 return 0;
2576 }
2577
opt_len(const char * s)2578 static inline int opt_len(const char *s)
2579 {
2580 bool open_quote = false;
2581 int len;
2582 char c;
2583
2584 for (len = 0; (c = s[len]) != '\0'; len++) {
2585 if (c == '"')
2586 open_quote = !open_quote;
2587 if (c == ',' && !open_quote)
2588 break;
2589 }
2590 return len;
2591 }
2592
selinux_sb_eat_lsm_opts(char * options,void ** mnt_opts)2593 static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
2594 {
2595 char *from = options;
2596 char *to = options;
2597 bool first = true;
2598 int rc;
2599
2600 while (1) {
2601 int len = opt_len(from);
2602 int token;
2603 char *arg = NULL;
2604
2605 token = match_opt_prefix(from, len, &arg);
2606
2607 if (token != Opt_error) {
2608 char *p, *q;
2609
2610 /* strip quotes */
2611 if (arg) {
2612 for (p = q = arg; p < from + len; p++) {
2613 char c = *p;
2614 if (c != '"')
2615 *q++ = c;
2616 }
2617 arg = kmemdup_nul(arg, q - arg, GFP_KERNEL);
2618 if (!arg) {
2619 rc = -ENOMEM;
2620 goto free_opt;
2621 }
2622 }
2623 rc = selinux_add_opt(token, arg, mnt_opts);
2624 kfree(arg);
2625 arg = NULL;
2626 if (unlikely(rc)) {
2627 goto free_opt;
2628 }
2629 } else {
2630 if (!first) { // copy with preceding comma
2631 from--;
2632 len++;
2633 }
2634 if (to != from)
2635 memmove(to, from, len);
2636 to += len;
2637 first = false;
2638 }
2639 if (!from[len])
2640 break;
2641 from += len + 1;
2642 }
2643 *to = '\0';
2644 return 0;
2645
2646 free_opt:
2647 if (*mnt_opts) {
2648 selinux_free_mnt_opts(*mnt_opts);
2649 *mnt_opts = NULL;
2650 }
2651 return rc;
2652 }
2653
selinux_sb_mnt_opts_compat(struct super_block * sb,void * mnt_opts)2654 static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts)
2655 {
2656 struct selinux_mnt_opts *opts = mnt_opts;
2657 struct superblock_security_struct *sbsec = selinux_superblock(sb);
2658
2659 /*
2660 * Superblock not initialized (i.e. no options) - reject if any
2661 * options specified, otherwise accept.
2662 */
2663 if (!(sbsec->flags & SE_SBINITIALIZED))
2664 return opts ? 1 : 0;
2665
2666 /*
2667 * Superblock initialized and no options specified - reject if
2668 * superblock has any options set, otherwise accept.
2669 */
2670 if (!opts)
2671 return (sbsec->flags & SE_MNTMASK) ? 1 : 0;
2672
2673 if (opts->fscontext_sid) {
2674 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
2675 opts->fscontext_sid))
2676 return 1;
2677 }
2678 if (opts->context_sid) {
2679 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
2680 opts->context_sid))
2681 return 1;
2682 }
2683 if (opts->rootcontext_sid) {
2684 struct inode_security_struct *root_isec;
2685
2686 root_isec = backing_inode_security(sb->s_root);
2687 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
2688 opts->rootcontext_sid))
2689 return 1;
2690 }
2691 if (opts->defcontext_sid) {
2692 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
2693 opts->defcontext_sid))
2694 return 1;
2695 }
2696 return 0;
2697 }
2698
selinux_sb_remount(struct super_block * sb,void * mnt_opts)2699 static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
2700 {
2701 struct selinux_mnt_opts *opts = mnt_opts;
2702 struct superblock_security_struct *sbsec = selinux_superblock(sb);
2703
2704 if (!(sbsec->flags & SE_SBINITIALIZED))
2705 return 0;
2706
2707 if (!opts)
2708 return 0;
2709
2710 if (opts->fscontext_sid) {
2711 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
2712 opts->fscontext_sid))
2713 goto out_bad_option;
2714 }
2715 if (opts->context_sid) {
2716 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
2717 opts->context_sid))
2718 goto out_bad_option;
2719 }
2720 if (opts->rootcontext_sid) {
2721 struct inode_security_struct *root_isec;
2722 root_isec = backing_inode_security(sb->s_root);
2723 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
2724 opts->rootcontext_sid))
2725 goto out_bad_option;
2726 }
2727 if (opts->defcontext_sid) {
2728 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
2729 opts->defcontext_sid))
2730 goto out_bad_option;
2731 }
2732 return 0;
2733
2734 out_bad_option:
2735 pr_warn("SELinux: unable to change security options "
2736 "during remount (dev %s, type=%s)\n", sb->s_id,
2737 sb->s_type->name);
2738 return -EINVAL;
2739 }
2740
selinux_sb_kern_mount(const struct super_block * sb)2741 static int selinux_sb_kern_mount(const struct super_block *sb)
2742 {
2743 const struct cred *cred = current_cred();
2744 struct common_audit_data ad;
2745
2746 ad.type = LSM_AUDIT_DATA_DENTRY;
2747 ad.u.dentry = sb->s_root;
2748 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2749 }
2750
selinux_sb_statfs(struct dentry * dentry)2751 static int selinux_sb_statfs(struct dentry *dentry)
2752 {
2753 const struct cred *cred = current_cred();
2754 struct common_audit_data ad;
2755
2756 ad.type = LSM_AUDIT_DATA_DENTRY;
2757 ad.u.dentry = dentry->d_sb->s_root;
2758 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2759 }
2760
selinux_mount(const char * dev_name,const struct path * path,const char * type,unsigned long flags,void * data)2761 static int selinux_mount(const char *dev_name,
2762 const struct path *path,
2763 const char *type,
2764 unsigned long flags,
2765 void *data)
2766 {
2767 const struct cred *cred = current_cred();
2768
2769 if (flags & MS_REMOUNT)
2770 return superblock_has_perm(cred, path->dentry->d_sb,
2771 FILESYSTEM__REMOUNT, NULL);
2772 else
2773 return path_has_perm(cred, path, FILE__MOUNTON);
2774 }
2775
selinux_move_mount(const struct path * from_path,const struct path * to_path)2776 static int selinux_move_mount(const struct path *from_path,
2777 const struct path *to_path)
2778 {
2779 const struct cred *cred = current_cred();
2780
2781 return path_has_perm(cred, to_path, FILE__MOUNTON);
2782 }
2783
selinux_umount(struct vfsmount * mnt,int flags)2784 static int selinux_umount(struct vfsmount *mnt, int flags)
2785 {
2786 const struct cred *cred = current_cred();
2787
2788 return superblock_has_perm(cred, mnt->mnt_sb,
2789 FILESYSTEM__UNMOUNT, NULL);
2790 }
2791
selinux_fs_context_submount(struct fs_context * fc,struct super_block * reference)2792 static int selinux_fs_context_submount(struct fs_context *fc,
2793 struct super_block *reference)
2794 {
2795 const struct superblock_security_struct *sbsec = selinux_superblock(reference);
2796 struct selinux_mnt_opts *opts;
2797
2798 /*
2799 * Ensure that fc->security remains NULL when no options are set
2800 * as expected by selinux_set_mnt_opts().
2801 */
2802 if (!(sbsec->flags & (FSCONTEXT_MNT|CONTEXT_MNT|DEFCONTEXT_MNT)))
2803 return 0;
2804
2805 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
2806 if (!opts)
2807 return -ENOMEM;
2808
2809 if (sbsec->flags & FSCONTEXT_MNT)
2810 opts->fscontext_sid = sbsec->sid;
2811 if (sbsec->flags & CONTEXT_MNT)
2812 opts->context_sid = sbsec->mntpoint_sid;
2813 if (sbsec->flags & DEFCONTEXT_MNT)
2814 opts->defcontext_sid = sbsec->def_sid;
2815 fc->security = opts;
2816 return 0;
2817 }
2818
selinux_fs_context_dup(struct fs_context * fc,struct fs_context * src_fc)2819 static int selinux_fs_context_dup(struct fs_context *fc,
2820 struct fs_context *src_fc)
2821 {
2822 const struct selinux_mnt_opts *src = src_fc->security;
2823
2824 if (!src)
2825 return 0;
2826
2827 fc->security = kmemdup(src, sizeof(*src), GFP_KERNEL);
2828 return fc->security ? 0 : -ENOMEM;
2829 }
2830
2831 static const struct fs_parameter_spec selinux_fs_parameters[] = {
2832 fsparam_string(CONTEXT_STR, Opt_context),
2833 fsparam_string(DEFCONTEXT_STR, Opt_defcontext),
2834 fsparam_string(FSCONTEXT_STR, Opt_fscontext),
2835 fsparam_string(ROOTCONTEXT_STR, Opt_rootcontext),
2836 fsparam_flag (SECLABEL_STR, Opt_seclabel),
2837 {}
2838 };
2839
selinux_fs_context_parse_param(struct fs_context * fc,struct fs_parameter * param)2840 static int selinux_fs_context_parse_param(struct fs_context *fc,
2841 struct fs_parameter *param)
2842 {
2843 struct fs_parse_result result;
2844 int opt;
2845
2846 opt = fs_parse(fc, selinux_fs_parameters, param, &result);
2847 if (opt < 0)
2848 return opt;
2849
2850 return selinux_add_opt(opt, param->string, &fc->security);
2851 }
2852
2853 /* inode security operations */
2854
selinux_inode_alloc_security(struct inode * inode)2855 static int selinux_inode_alloc_security(struct inode *inode)
2856 {
2857 struct inode_security_struct *isec = selinux_inode(inode);
2858 u32 sid = current_sid();
2859
2860 spin_lock_init(&isec->lock);
2861 INIT_LIST_HEAD(&isec->list);
2862 isec->inode = inode;
2863 isec->sid = SECINITSID_UNLABELED;
2864 isec->sclass = SECCLASS_FILE;
2865 isec->task_sid = sid;
2866 isec->initialized = LABEL_INVALID;
2867
2868 return 0;
2869 }
2870
selinux_inode_free_security(struct inode * inode)2871 static void selinux_inode_free_security(struct inode *inode)
2872 {
2873 inode_free_security(inode);
2874 }
2875
selinux_dentry_init_security(struct dentry * dentry,int mode,const struct qstr * name,const char ** xattr_name,void ** ctx,u32 * ctxlen)2876 static int selinux_dentry_init_security(struct dentry *dentry, int mode,
2877 const struct qstr *name,
2878 const char **xattr_name, void **ctx,
2879 u32 *ctxlen)
2880 {
2881 u32 newsid;
2882 int rc;
2883
2884 rc = selinux_determine_inode_label(selinux_cred(current_cred()),
2885 d_inode(dentry->d_parent), name,
2886 inode_mode_to_security_class(mode),
2887 &newsid);
2888 if (rc)
2889 return rc;
2890
2891 if (xattr_name)
2892 *xattr_name = XATTR_NAME_SELINUX;
2893
2894 return security_sid_to_context(newsid, (char **)ctx,
2895 ctxlen);
2896 }
2897
selinux_dentry_create_files_as(struct dentry * dentry,int mode,struct qstr * name,const struct cred * old,struct cred * new)2898 static int selinux_dentry_create_files_as(struct dentry *dentry, int mode,
2899 struct qstr *name,
2900 const struct cred *old,
2901 struct cred *new)
2902 {
2903 u32 newsid;
2904 int rc;
2905 struct task_security_struct *tsec;
2906
2907 rc = selinux_determine_inode_label(selinux_cred(old),
2908 d_inode(dentry->d_parent), name,
2909 inode_mode_to_security_class(mode),
2910 &newsid);
2911 if (rc)
2912 return rc;
2913
2914 tsec = selinux_cred(new);
2915 tsec->create_sid = newsid;
2916 return 0;
2917 }
2918
selinux_inode_init_security(struct inode * inode,struct inode * dir,const struct qstr * qstr,struct xattr * xattrs,int * xattr_count)2919 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2920 const struct qstr *qstr,
2921 struct xattr *xattrs, int *xattr_count)
2922 {
2923 const struct task_security_struct *tsec = selinux_cred(current_cred());
2924 struct superblock_security_struct *sbsec;
2925 struct xattr *xattr = lsm_get_xattr_slot(xattrs, xattr_count);
2926 u32 newsid, clen;
2927 u16 newsclass;
2928 int rc;
2929 char *context;
2930
2931 sbsec = selinux_superblock(dir->i_sb);
2932
2933 newsid = tsec->create_sid;
2934 newsclass = inode_mode_to_security_class(inode->i_mode);
2935 rc = selinux_determine_inode_label(tsec, dir, qstr, newsclass, &newsid);
2936 if (rc)
2937 return rc;
2938
2939 /* Possibly defer initialization to selinux_complete_init. */
2940 if (sbsec->flags & SE_SBINITIALIZED) {
2941 struct inode_security_struct *isec = selinux_inode(inode);
2942 isec->sclass = newsclass;
2943 isec->sid = newsid;
2944 isec->initialized = LABEL_INITIALIZED;
2945 }
2946
2947 if (!selinux_initialized() ||
2948 !(sbsec->flags & SBLABEL_MNT))
2949 return -EOPNOTSUPP;
2950
2951 if (xattr) {
2952 rc = security_sid_to_context_force(newsid,
2953 &context, &clen);
2954 if (rc)
2955 return rc;
2956 xattr->value = context;
2957 xattr->value_len = clen;
2958 xattr->name = XATTR_SELINUX_SUFFIX;
2959 }
2960
2961 return 0;
2962 }
2963
selinux_inode_init_security_anon(struct inode * inode,const struct qstr * name,const struct inode * context_inode)2964 static int selinux_inode_init_security_anon(struct inode *inode,
2965 const struct qstr *name,
2966 const struct inode *context_inode)
2967 {
2968 u32 sid = current_sid();
2969 struct common_audit_data ad;
2970 struct inode_security_struct *isec;
2971 int rc;
2972
2973 if (unlikely(!selinux_initialized()))
2974 return 0;
2975
2976 isec = selinux_inode(inode);
2977
2978 /*
2979 * We only get here once per ephemeral inode. The inode has
2980 * been initialized via inode_alloc_security but is otherwise
2981 * untouched.
2982 */
2983
2984 if (context_inode) {
2985 struct inode_security_struct *context_isec =
2986 selinux_inode(context_inode);
2987 if (context_isec->initialized != LABEL_INITIALIZED) {
2988 pr_err("SELinux: context_inode is not initialized\n");
2989 return -EACCES;
2990 }
2991
2992 isec->sclass = context_isec->sclass;
2993 isec->sid = context_isec->sid;
2994 } else {
2995 isec->sclass = SECCLASS_ANON_INODE;
2996 rc = security_transition_sid(
2997 sid, sid,
2998 isec->sclass, name, &isec->sid);
2999 if (rc)
3000 return rc;
3001 }
3002
3003 isec->initialized = LABEL_INITIALIZED;
3004 /*
3005 * Now that we've initialized security, check whether we're
3006 * allowed to actually create this type of anonymous inode.
3007 */
3008
3009 ad.type = LSM_AUDIT_DATA_ANONINODE;
3010 ad.u.anonclass = name ? (const char *)name->name : "?";
3011
3012 return avc_has_perm(sid,
3013 isec->sid,
3014 isec->sclass,
3015 FILE__CREATE,
3016 &ad);
3017 }
3018
selinux_inode_create(struct inode * dir,struct dentry * dentry,umode_t mode)3019 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
3020 {
3021 return may_create(dir, dentry, SECCLASS_FILE);
3022 }
3023
selinux_inode_link(struct dentry * old_dentry,struct inode * dir,struct dentry * new_dentry)3024 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
3025 {
3026 return may_link(dir, old_dentry, MAY_LINK);
3027 }
3028
selinux_inode_unlink(struct inode * dir,struct dentry * dentry)3029 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
3030 {
3031 return may_link(dir, dentry, MAY_UNLINK);
3032 }
3033
selinux_inode_symlink(struct inode * dir,struct dentry * dentry,const char * name)3034 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
3035 {
3036 return may_create(dir, dentry, SECCLASS_LNK_FILE);
3037 }
3038
selinux_inode_mkdir(struct inode * dir,struct dentry * dentry,umode_t mask)3039 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
3040 {
3041 return may_create(dir, dentry, SECCLASS_DIR);
3042 }
3043
selinux_inode_rmdir(struct inode * dir,struct dentry * dentry)3044 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
3045 {
3046 return may_link(dir, dentry, MAY_RMDIR);
3047 }
3048
selinux_inode_mknod(struct inode * dir,struct dentry * dentry,umode_t mode,dev_t dev)3049 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
3050 {
3051 return may_create(dir, dentry, inode_mode_to_security_class(mode));
3052 }
3053
selinux_inode_rename(struct inode * old_inode,struct dentry * old_dentry,struct inode * new_inode,struct dentry * new_dentry)3054 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
3055 struct inode *new_inode, struct dentry *new_dentry)
3056 {
3057 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
3058 }
3059
selinux_inode_readlink(struct dentry * dentry)3060 static int selinux_inode_readlink(struct dentry *dentry)
3061 {
3062 const struct cred *cred = current_cred();
3063
3064 return dentry_has_perm(cred, dentry, FILE__READ);
3065 }
3066
selinux_inode_follow_link(struct dentry * dentry,struct inode * inode,bool rcu)3067 static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
3068 bool rcu)
3069 {
3070 struct common_audit_data ad;
3071 struct inode_security_struct *isec;
3072 u32 sid = current_sid();
3073
3074 ad.type = LSM_AUDIT_DATA_DENTRY;
3075 ad.u.dentry = dentry;
3076 isec = inode_security_rcu(inode, rcu);
3077 if (IS_ERR(isec))
3078 return PTR_ERR(isec);
3079
3080 return avc_has_perm(sid, isec->sid, isec->sclass, FILE__READ, &ad);
3081 }
3082
audit_inode_permission(struct inode * inode,u32 perms,u32 audited,u32 denied,int result)3083 static noinline int audit_inode_permission(struct inode *inode,
3084 u32 perms, u32 audited, u32 denied,
3085 int result)
3086 {
3087 struct common_audit_data ad;
3088 struct inode_security_struct *isec = selinux_inode(inode);
3089
3090 ad.type = LSM_AUDIT_DATA_INODE;
3091 ad.u.inode = inode;
3092
3093 return slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms,
3094 audited, denied, result, &ad);
3095 }
3096
selinux_inode_permission(struct inode * inode,int mask)3097 static int selinux_inode_permission(struct inode *inode, int mask)
3098 {
3099 u32 perms;
3100 bool from_access;
3101 bool no_block = mask & MAY_NOT_BLOCK;
3102 struct inode_security_struct *isec;
3103 u32 sid = current_sid();
3104 struct av_decision avd;
3105 int rc, rc2;
3106 u32 audited, denied;
3107
3108 from_access = mask & MAY_ACCESS;
3109 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
3110
3111 /* No permission to check. Existence test. */
3112 if (!mask)
3113 return 0;
3114
3115 if (unlikely(IS_PRIVATE(inode)))
3116 return 0;
3117
3118 perms = file_mask_to_av(inode->i_mode, mask);
3119
3120 isec = inode_security_rcu(inode, no_block);
3121 if (IS_ERR(isec))
3122 return PTR_ERR(isec);
3123
3124 rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0,
3125 &avd);
3126 audited = avc_audit_required(perms, &avd, rc,
3127 from_access ? FILE__AUDIT_ACCESS : 0,
3128 &denied);
3129 if (likely(!audited))
3130 return rc;
3131
3132 rc2 = audit_inode_permission(inode, perms, audited, denied, rc);
3133 if (rc2)
3134 return rc2;
3135 return rc;
3136 }
3137
selinux_inode_setattr(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * iattr)3138 static int selinux_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
3139 struct iattr *iattr)
3140 {
3141 const struct cred *cred = current_cred();
3142 struct inode *inode = d_backing_inode(dentry);
3143 unsigned int ia_valid = iattr->ia_valid;
3144 __u32 av = FILE__WRITE;
3145
3146 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
3147 if (ia_valid & ATTR_FORCE) {
3148 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
3149 ATTR_FORCE);
3150 if (!ia_valid)
3151 return 0;
3152 }
3153
3154 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
3155 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
3156 return dentry_has_perm(cred, dentry, FILE__SETATTR);
3157
3158 if (selinux_policycap_openperm() &&
3159 inode->i_sb->s_magic != SOCKFS_MAGIC &&
3160 (ia_valid & ATTR_SIZE) &&
3161 !(ia_valid & ATTR_FILE))
3162 av |= FILE__OPEN;
3163
3164 return dentry_has_perm(cred, dentry, av);
3165 }
3166
selinux_inode_getattr(const struct path * path)3167 static int selinux_inode_getattr(const struct path *path)
3168 {
3169 return path_has_perm(current_cred(), path, FILE__GETATTR);
3170 }
3171
has_cap_mac_admin(bool audit)3172 static bool has_cap_mac_admin(bool audit)
3173 {
3174 const struct cred *cred = current_cred();
3175 unsigned int opts = audit ? CAP_OPT_NONE : CAP_OPT_NOAUDIT;
3176
3177 if (cap_capable(cred, &init_user_ns, CAP_MAC_ADMIN, opts))
3178 return false;
3179 if (cred_has_capability(cred, CAP_MAC_ADMIN, opts, true))
3180 return false;
3181 return true;
3182 }
3183
3184 /**
3185 * selinux_inode_xattr_skipcap - Skip the xattr capability checks?
3186 * @name: name of the xattr
3187 *
3188 * Returns 1 to indicate that SELinux "owns" the access control rights to xattrs
3189 * named @name; the LSM layer should avoid enforcing any traditional
3190 * capability based access controls on this xattr. Returns 0 to indicate that
3191 * SELinux does not "own" the access control rights to xattrs named @name and is
3192 * deferring to the LSM layer for further access controls, including capability
3193 * based controls.
3194 */
selinux_inode_xattr_skipcap(const char * name)3195 static int selinux_inode_xattr_skipcap(const char *name)
3196 {
3197 /* require capability check if not a selinux xattr */
3198 return !strcmp(name, XATTR_NAME_SELINUX);
3199 }
3200
selinux_inode_setxattr(struct mnt_idmap * idmap,struct dentry * dentry,const char * name,const void * value,size_t size,int flags)3201 static int selinux_inode_setxattr(struct mnt_idmap *idmap,
3202 struct dentry *dentry, const char *name,
3203 const void *value, size_t size, int flags)
3204 {
3205 struct inode *inode = d_backing_inode(dentry);
3206 struct inode_security_struct *isec;
3207 struct superblock_security_struct *sbsec;
3208 struct common_audit_data ad;
3209 u32 newsid, sid = current_sid();
3210 int rc = 0;
3211
3212 /* if not a selinux xattr, only check the ordinary setattr perm */
3213 if (strcmp(name, XATTR_NAME_SELINUX))
3214 return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3215
3216 if (!selinux_initialized())
3217 return (inode_owner_or_capable(idmap, inode) ? 0 : -EPERM);
3218
3219 sbsec = selinux_superblock(inode->i_sb);
3220 if (!(sbsec->flags & SBLABEL_MNT))
3221 return -EOPNOTSUPP;
3222
3223 if (!inode_owner_or_capable(idmap, inode))
3224 return -EPERM;
3225
3226 ad.type = LSM_AUDIT_DATA_DENTRY;
3227 ad.u.dentry = dentry;
3228
3229 isec = backing_inode_security(dentry);
3230 rc = avc_has_perm(sid, isec->sid, isec->sclass,
3231 FILE__RELABELFROM, &ad);
3232 if (rc)
3233 return rc;
3234
3235 rc = security_context_to_sid(value, size, &newsid,
3236 GFP_KERNEL);
3237 if (rc == -EINVAL) {
3238 if (!has_cap_mac_admin(true)) {
3239 struct audit_buffer *ab;
3240 size_t audit_size;
3241
3242 /* We strip a nul only if it is at the end, otherwise the
3243 * context contains a nul and we should audit that */
3244 if (value) {
3245 const char *str = value;
3246
3247 if (str[size - 1] == '\0')
3248 audit_size = size - 1;
3249 else
3250 audit_size = size;
3251 } else {
3252 audit_size = 0;
3253 }
3254 ab = audit_log_start(audit_context(),
3255 GFP_ATOMIC, AUDIT_SELINUX_ERR);
3256 if (!ab)
3257 return rc;
3258 audit_log_format(ab, "op=setxattr invalid_context=");
3259 audit_log_n_untrustedstring(ab, value, audit_size);
3260 audit_log_end(ab);
3261
3262 return rc;
3263 }
3264 rc = security_context_to_sid_force(value,
3265 size, &newsid);
3266 }
3267 if (rc)
3268 return rc;
3269
3270 rc = avc_has_perm(sid, newsid, isec->sclass,
3271 FILE__RELABELTO, &ad);
3272 if (rc)
3273 return rc;
3274
3275 rc = security_validate_transition(isec->sid, newsid,
3276 sid, isec->sclass);
3277 if (rc)
3278 return rc;
3279
3280 return avc_has_perm(newsid,
3281 sbsec->sid,
3282 SECCLASS_FILESYSTEM,
3283 FILESYSTEM__ASSOCIATE,
3284 &ad);
3285 }
3286
selinux_inode_set_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name,struct posix_acl * kacl)3287 static int selinux_inode_set_acl(struct mnt_idmap *idmap,
3288 struct dentry *dentry, const char *acl_name,
3289 struct posix_acl *kacl)
3290 {
3291 return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3292 }
3293
selinux_inode_get_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name)3294 static int selinux_inode_get_acl(struct mnt_idmap *idmap,
3295 struct dentry *dentry, const char *acl_name)
3296 {
3297 return dentry_has_perm(current_cred(), dentry, FILE__GETATTR);
3298 }
3299
selinux_inode_remove_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name)3300 static int selinux_inode_remove_acl(struct mnt_idmap *idmap,
3301 struct dentry *dentry, const char *acl_name)
3302 {
3303 return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3304 }
3305
selinux_inode_post_setxattr(struct dentry * dentry,const char * name,const void * value,size_t size,int flags)3306 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
3307 const void *value, size_t size,
3308 int flags)
3309 {
3310 struct inode *inode = d_backing_inode(dentry);
3311 struct inode_security_struct *isec;
3312 u32 newsid;
3313 int rc;
3314
3315 if (strcmp(name, XATTR_NAME_SELINUX)) {
3316 /* Not an attribute we recognize, so nothing to do. */
3317 return;
3318 }
3319
3320 if (!selinux_initialized()) {
3321 /* If we haven't even been initialized, then we can't validate
3322 * against a policy, so leave the label as invalid. It may
3323 * resolve to a valid label on the next revalidation try if
3324 * we've since initialized.
3325 */
3326 return;
3327 }
3328
3329 rc = security_context_to_sid_force(value, size,
3330 &newsid);
3331 if (rc) {
3332 pr_err("SELinux: unable to map context to SID"
3333 "for (%s, %lu), rc=%d\n",
3334 inode->i_sb->s_id, inode->i_ino, -rc);
3335 return;
3336 }
3337
3338 isec = backing_inode_security(dentry);
3339 spin_lock(&isec->lock);
3340 isec->sclass = inode_mode_to_security_class(inode->i_mode);
3341 isec->sid = newsid;
3342 isec->initialized = LABEL_INITIALIZED;
3343 spin_unlock(&isec->lock);
3344 }
3345
selinux_inode_getxattr(struct dentry * dentry,const char * name)3346 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
3347 {
3348 const struct cred *cred = current_cred();
3349
3350 return dentry_has_perm(cred, dentry, FILE__GETATTR);
3351 }
3352
selinux_inode_listxattr(struct dentry * dentry)3353 static int selinux_inode_listxattr(struct dentry *dentry)
3354 {
3355 const struct cred *cred = current_cred();
3356
3357 return dentry_has_perm(cred, dentry, FILE__GETATTR);
3358 }
3359
selinux_inode_removexattr(struct mnt_idmap * idmap,struct dentry * dentry,const char * name)3360 static int selinux_inode_removexattr(struct mnt_idmap *idmap,
3361 struct dentry *dentry, const char *name)
3362 {
3363 /* if not a selinux xattr, only check the ordinary setattr perm */
3364 if (strcmp(name, XATTR_NAME_SELINUX))
3365 return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3366
3367 if (!selinux_initialized())
3368 return 0;
3369
3370 /* No one is allowed to remove a SELinux security label.
3371 You can change the label, but all data must be labeled. */
3372 return -EACCES;
3373 }
3374
selinux_path_notify(const struct path * path,u64 mask,unsigned int obj_type)3375 static int selinux_path_notify(const struct path *path, u64 mask,
3376 unsigned int obj_type)
3377 {
3378 int ret;
3379 u32 perm;
3380
3381 struct common_audit_data ad;
3382
3383 ad.type = LSM_AUDIT_DATA_PATH;
3384 ad.u.path = *path;
3385
3386 /*
3387 * Set permission needed based on the type of mark being set.
3388 * Performs an additional check for sb watches.
3389 */
3390 switch (obj_type) {
3391 case FSNOTIFY_OBJ_TYPE_VFSMOUNT:
3392 perm = FILE__WATCH_MOUNT;
3393 break;
3394 case FSNOTIFY_OBJ_TYPE_SB:
3395 perm = FILE__WATCH_SB;
3396 ret = superblock_has_perm(current_cred(), path->dentry->d_sb,
3397 FILESYSTEM__WATCH, &ad);
3398 if (ret)
3399 return ret;
3400 break;
3401 case FSNOTIFY_OBJ_TYPE_INODE:
3402 perm = FILE__WATCH;
3403 break;
3404 default:
3405 return -EINVAL;
3406 }
3407
3408 /* blocking watches require the file:watch_with_perm permission */
3409 if (mask & (ALL_FSNOTIFY_PERM_EVENTS))
3410 perm |= FILE__WATCH_WITH_PERM;
3411
3412 /* watches on read-like events need the file:watch_reads permission */
3413 if (mask & (FS_ACCESS | FS_ACCESS_PERM | FS_CLOSE_NOWRITE))
3414 perm |= FILE__WATCH_READS;
3415
3416 return path_has_perm(current_cred(), path, perm);
3417 }
3418
3419 /*
3420 * Copy the inode security context value to the user.
3421 *
3422 * Permission check is handled by selinux_inode_getxattr hook.
3423 */
selinux_inode_getsecurity(struct mnt_idmap * idmap,struct inode * inode,const char * name,void ** buffer,bool alloc)3424 static int selinux_inode_getsecurity(struct mnt_idmap *idmap,
3425 struct inode *inode, const char *name,
3426 void **buffer, bool alloc)
3427 {
3428 u32 size;
3429 int error;
3430 char *context = NULL;
3431 struct inode_security_struct *isec;
3432
3433 /*
3434 * If we're not initialized yet, then we can't validate contexts, so
3435 * just let vfs_getxattr fall back to using the on-disk xattr.
3436 */
3437 if (!selinux_initialized() ||
3438 strcmp(name, XATTR_SELINUX_SUFFIX))
3439 return -EOPNOTSUPP;
3440
3441 /*
3442 * If the caller has CAP_MAC_ADMIN, then get the raw context
3443 * value even if it is not defined by current policy; otherwise,
3444 * use the in-core value under current policy.
3445 * Use the non-auditing forms of the permission checks since
3446 * getxattr may be called by unprivileged processes commonly
3447 * and lack of permission just means that we fall back to the
3448 * in-core context value, not a denial.
3449 */
3450 isec = inode_security(inode);
3451 if (has_cap_mac_admin(false))
3452 error = security_sid_to_context_force(isec->sid, &context,
3453 &size);
3454 else
3455 error = security_sid_to_context(isec->sid,
3456 &context, &size);
3457 if (error)
3458 return error;
3459 error = size;
3460 if (alloc) {
3461 *buffer = context;
3462 goto out_nofree;
3463 }
3464 kfree(context);
3465 out_nofree:
3466 return error;
3467 }
3468
selinux_inode_setsecurity(struct inode * inode,const char * name,const void * value,size_t size,int flags)3469 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
3470 const void *value, size_t size, int flags)
3471 {
3472 struct inode_security_struct *isec = inode_security_novalidate(inode);
3473 struct superblock_security_struct *sbsec;
3474 u32 newsid;
3475 int rc;
3476
3477 if (strcmp(name, XATTR_SELINUX_SUFFIX))
3478 return -EOPNOTSUPP;
3479
3480 sbsec = selinux_superblock(inode->i_sb);
3481 if (!(sbsec->flags & SBLABEL_MNT))
3482 return -EOPNOTSUPP;
3483
3484 if (!value || !size)
3485 return -EACCES;
3486
3487 rc = security_context_to_sid(value, size, &newsid,
3488 GFP_KERNEL);
3489 if (rc)
3490 return rc;
3491
3492 spin_lock(&isec->lock);
3493 isec->sclass = inode_mode_to_security_class(inode->i_mode);
3494 isec->sid = newsid;
3495 isec->initialized = LABEL_INITIALIZED;
3496 spin_unlock(&isec->lock);
3497 return 0;
3498 }
3499
selinux_inode_listsecurity(struct inode * inode,char * buffer,size_t buffer_size)3500 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
3501 {
3502 const int len = sizeof(XATTR_NAME_SELINUX);
3503
3504 if (!selinux_initialized())
3505 return 0;
3506
3507 if (buffer && len <= buffer_size)
3508 memcpy(buffer, XATTR_NAME_SELINUX, len);
3509 return len;
3510 }
3511
selinux_inode_getsecid(struct inode * inode,u32 * secid)3512 static void selinux_inode_getsecid(struct inode *inode, u32 *secid)
3513 {
3514 struct inode_security_struct *isec = inode_security_novalidate(inode);
3515 *secid = isec->sid;
3516 }
3517
selinux_inode_copy_up(struct dentry * src,struct cred ** new)3518 static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
3519 {
3520 u32 sid;
3521 struct task_security_struct *tsec;
3522 struct cred *new_creds = *new;
3523
3524 if (new_creds == NULL) {
3525 new_creds = prepare_creds();
3526 if (!new_creds)
3527 return -ENOMEM;
3528 }
3529
3530 tsec = selinux_cred(new_creds);
3531 /* Get label from overlay inode and set it in create_sid */
3532 selinux_inode_getsecid(d_inode(src), &sid);
3533 tsec->create_sid = sid;
3534 *new = new_creds;
3535 return 0;
3536 }
3537
selinux_inode_copy_up_xattr(struct dentry * dentry,const char * name)3538 static int selinux_inode_copy_up_xattr(struct dentry *dentry, const char *name)
3539 {
3540 /* The copy_up hook above sets the initial context on an inode, but we
3541 * don't then want to overwrite it by blindly copying all the lower
3542 * xattrs up. Instead, filter out SELinux-related xattrs following
3543 * policy load.
3544 */
3545 if (selinux_initialized() && !strcmp(name, XATTR_NAME_SELINUX))
3546 return -ECANCELED; /* Discard */
3547 /*
3548 * Any other attribute apart from SELINUX is not claimed, supported
3549 * by selinux.
3550 */
3551 return -EOPNOTSUPP;
3552 }
3553
3554 /* kernfs node operations */
3555
selinux_kernfs_init_security(struct kernfs_node * kn_dir,struct kernfs_node * kn)3556 static int selinux_kernfs_init_security(struct kernfs_node *kn_dir,
3557 struct kernfs_node *kn)
3558 {
3559 const struct task_security_struct *tsec = selinux_cred(current_cred());
3560 u32 parent_sid, newsid, clen;
3561 int rc;
3562 char *context;
3563
3564 rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, NULL, 0);
3565 if (rc == -ENODATA)
3566 return 0;
3567 else if (rc < 0)
3568 return rc;
3569
3570 clen = (u32)rc;
3571 context = kmalloc(clen, GFP_KERNEL);
3572 if (!context)
3573 return -ENOMEM;
3574
3575 rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, context, clen);
3576 if (rc < 0) {
3577 kfree(context);
3578 return rc;
3579 }
3580
3581 rc = security_context_to_sid(context, clen, &parent_sid,
3582 GFP_KERNEL);
3583 kfree(context);
3584 if (rc)
3585 return rc;
3586
3587 if (tsec->create_sid) {
3588 newsid = tsec->create_sid;
3589 } else {
3590 u16 secclass = inode_mode_to_security_class(kn->mode);
3591 struct qstr q;
3592
3593 q.name = kn->name;
3594 q.hash_len = hashlen_string(kn_dir, kn->name);
3595
3596 rc = security_transition_sid(tsec->sid,
3597 parent_sid, secclass, &q,
3598 &newsid);
3599 if (rc)
3600 return rc;
3601 }
3602
3603 rc = security_sid_to_context_force(newsid,
3604 &context, &clen);
3605 if (rc)
3606 return rc;
3607
3608 rc = kernfs_xattr_set(kn, XATTR_NAME_SELINUX, context, clen,
3609 XATTR_CREATE);
3610 kfree(context);
3611 return rc;
3612 }
3613
3614
3615 /* file security operations */
3616
selinux_revalidate_file_permission(struct file * file,int mask)3617 static int selinux_revalidate_file_permission(struct file *file, int mask)
3618 {
3619 const struct cred *cred = current_cred();
3620 struct inode *inode = file_inode(file);
3621
3622 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
3623 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
3624 mask |= MAY_APPEND;
3625
3626 return file_has_perm(cred, file,
3627 file_mask_to_av(inode->i_mode, mask));
3628 }
3629
selinux_file_permission(struct file * file,int mask)3630 static int selinux_file_permission(struct file *file, int mask)
3631 {
3632 struct inode *inode = file_inode(file);
3633 struct file_security_struct *fsec = selinux_file(file);
3634 struct inode_security_struct *isec;
3635 u32 sid = current_sid();
3636
3637 if (!mask)
3638 /* No permission to check. Existence test. */
3639 return 0;
3640
3641 isec = inode_security(inode);
3642 if (sid == fsec->sid && fsec->isid == isec->sid &&
3643 fsec->pseqno == avc_policy_seqno())
3644 /* No change since file_open check. */
3645 return 0;
3646
3647 return selinux_revalidate_file_permission(file, mask);
3648 }
3649
selinux_file_alloc_security(struct file * file)3650 static int selinux_file_alloc_security(struct file *file)
3651 {
3652 struct file_security_struct *fsec = selinux_file(file);
3653 u32 sid = current_sid();
3654
3655 fsec->sid = sid;
3656 fsec->fown_sid = sid;
3657
3658 return 0;
3659 }
3660
3661 /*
3662 * Check whether a task has the ioctl permission and cmd
3663 * operation to an inode.
3664 */
ioctl_has_perm(const struct cred * cred,struct file * file,u32 requested,u16 cmd)3665 static int ioctl_has_perm(const struct cred *cred, struct file *file,
3666 u32 requested, u16 cmd)
3667 {
3668 struct common_audit_data ad;
3669 struct file_security_struct *fsec = selinux_file(file);
3670 struct inode *inode = file_inode(file);
3671 struct inode_security_struct *isec;
3672 struct lsm_ioctlop_audit ioctl;
3673 u32 ssid = cred_sid(cred);
3674 int rc;
3675 u8 driver = cmd >> 8;
3676 u8 xperm = cmd & 0xff;
3677
3678 ad.type = LSM_AUDIT_DATA_IOCTL_OP;
3679 ad.u.op = &ioctl;
3680 ad.u.op->cmd = cmd;
3681 ad.u.op->path = file->f_path;
3682
3683 if (ssid != fsec->sid) {
3684 rc = avc_has_perm(ssid, fsec->sid,
3685 SECCLASS_FD,
3686 FD__USE,
3687 &ad);
3688 if (rc)
3689 goto out;
3690 }
3691
3692 if (unlikely(IS_PRIVATE(inode)))
3693 return 0;
3694
3695 isec = inode_security(inode);
3696 rc = avc_has_extended_perms(ssid, isec->sid, isec->sclass,
3697 requested, driver, xperm, &ad);
3698 out:
3699 return rc;
3700 }
3701
selinux_file_ioctl(struct file * file,unsigned int cmd,unsigned long arg)3702 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
3703 unsigned long arg)
3704 {
3705 const struct cred *cred = current_cred();
3706 int error = 0;
3707
3708 switch (cmd) {
3709 case FIONREAD:
3710 case FIBMAP:
3711 case FIGETBSZ:
3712 case FS_IOC_GETFLAGS:
3713 case FS_IOC_GETVERSION:
3714 error = file_has_perm(cred, file, FILE__GETATTR);
3715 break;
3716
3717 case FS_IOC_SETFLAGS:
3718 case FS_IOC_SETVERSION:
3719 error = file_has_perm(cred, file, FILE__SETATTR);
3720 break;
3721
3722 /* sys_ioctl() checks */
3723 case FIONBIO:
3724 case FIOASYNC:
3725 error = file_has_perm(cred, file, 0);
3726 break;
3727
3728 case KDSKBENT:
3729 case KDSKBSENT:
3730 error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3731 CAP_OPT_NONE, true);
3732 break;
3733
3734 case FIOCLEX:
3735 case FIONCLEX:
3736 if (!selinux_policycap_ioctl_skip_cloexec())
3737 error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3738 break;
3739
3740 /* default case assumes that the command will go
3741 * to the file's ioctl() function.
3742 */
3743 default:
3744 error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3745 }
3746 return error;
3747 }
3748
selinux_file_ioctl_compat(struct file * file,unsigned int cmd,unsigned long arg)3749 static int selinux_file_ioctl_compat(struct file *file, unsigned int cmd,
3750 unsigned long arg)
3751 {
3752 /*
3753 * If we are in a 64-bit kernel running 32-bit userspace, we need to
3754 * make sure we don't compare 32-bit flags to 64-bit flags.
3755 */
3756 switch (cmd) {
3757 case FS_IOC32_GETFLAGS:
3758 cmd = FS_IOC_GETFLAGS;
3759 break;
3760 case FS_IOC32_SETFLAGS:
3761 cmd = FS_IOC_SETFLAGS;
3762 break;
3763 case FS_IOC32_GETVERSION:
3764 cmd = FS_IOC_GETVERSION;
3765 break;
3766 case FS_IOC32_SETVERSION:
3767 cmd = FS_IOC_SETVERSION;
3768 break;
3769 default:
3770 break;
3771 }
3772
3773 return selinux_file_ioctl(file, cmd, arg);
3774 }
3775
3776 static int default_noexec __ro_after_init;
3777
file_map_prot_check(struct file * file,unsigned long prot,int shared)3778 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3779 {
3780 const struct cred *cred = current_cred();
3781 u32 sid = cred_sid(cred);
3782 int rc = 0;
3783
3784 if (default_noexec &&
3785 (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) ||
3786 (!shared && (prot & PROT_WRITE)))) {
3787 /*
3788 * We are making executable an anonymous mapping or a
3789 * private file mapping that will also be writable.
3790 * This has an additional check.
3791 */
3792 rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
3793 PROCESS__EXECMEM, NULL);
3794 if (rc)
3795 goto error;
3796 }
3797
3798 if (file) {
3799 /* read access is always possible with a mapping */
3800 u32 av = FILE__READ;
3801
3802 /* write access only matters if the mapping is shared */
3803 if (shared && (prot & PROT_WRITE))
3804 av |= FILE__WRITE;
3805
3806 if (prot & PROT_EXEC)
3807 av |= FILE__EXECUTE;
3808
3809 return file_has_perm(cred, file, av);
3810 }
3811
3812 error:
3813 return rc;
3814 }
3815
selinux_mmap_addr(unsigned long addr)3816 static int selinux_mmap_addr(unsigned long addr)
3817 {
3818 int rc = 0;
3819
3820 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3821 u32 sid = current_sid();
3822 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3823 MEMPROTECT__MMAP_ZERO, NULL);
3824 }
3825
3826 return rc;
3827 }
3828
selinux_mmap_file(struct file * file,unsigned long reqprot __always_unused,unsigned long prot,unsigned long flags)3829 static int selinux_mmap_file(struct file *file,
3830 unsigned long reqprot __always_unused,
3831 unsigned long prot, unsigned long flags)
3832 {
3833 struct common_audit_data ad;
3834 int rc;
3835
3836 if (file) {
3837 ad.type = LSM_AUDIT_DATA_FILE;
3838 ad.u.file = file;
3839 rc = inode_has_perm(current_cred(), file_inode(file),
3840 FILE__MAP, &ad);
3841 if (rc)
3842 return rc;
3843 }
3844
3845 return file_map_prot_check(file, prot,
3846 (flags & MAP_TYPE) == MAP_SHARED);
3847 }
3848
selinux_file_mprotect(struct vm_area_struct * vma,unsigned long reqprot __always_unused,unsigned long prot)3849 static int selinux_file_mprotect(struct vm_area_struct *vma,
3850 unsigned long reqprot __always_unused,
3851 unsigned long prot)
3852 {
3853 const struct cred *cred = current_cred();
3854 u32 sid = cred_sid(cred);
3855
3856 if (default_noexec &&
3857 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3858 int rc = 0;
3859 /*
3860 * We don't use the vma_is_initial_heap() helper as it has
3861 * a history of problems and is currently broken on systems
3862 * where there is no heap, e.g. brk == start_brk. Before
3863 * replacing the conditional below with vma_is_initial_heap(),
3864 * or something similar, please ensure that the logic is the
3865 * same as what we have below or you have tested every possible
3866 * corner case you can think to test.
3867 */
3868 if (vma->vm_start >= vma->vm_mm->start_brk &&
3869 vma->vm_end <= vma->vm_mm->brk) {
3870 rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
3871 PROCESS__EXECHEAP, NULL);
3872 } else if (!vma->vm_file && (vma_is_initial_stack(vma) ||
3873 vma_is_stack_for_current(vma))) {
3874 rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
3875 PROCESS__EXECSTACK, NULL);
3876 } else if (vma->vm_file && vma->anon_vma) {
3877 /*
3878 * We are making executable a file mapping that has
3879 * had some COW done. Since pages might have been
3880 * written, check ability to execute the possibly
3881 * modified content. This typically should only
3882 * occur for text relocations.
3883 */
3884 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3885 }
3886 if (rc)
3887 return rc;
3888 }
3889
3890 return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3891 }
3892
selinux_file_lock(struct file * file,unsigned int cmd)3893 static int selinux_file_lock(struct file *file, unsigned int cmd)
3894 {
3895 const struct cred *cred = current_cred();
3896
3897 return file_has_perm(cred, file, FILE__LOCK);
3898 }
3899
selinux_file_fcntl(struct file * file,unsigned int cmd,unsigned long arg)3900 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3901 unsigned long arg)
3902 {
3903 const struct cred *cred = current_cred();
3904 int err = 0;
3905
3906 switch (cmd) {
3907 case F_SETFL:
3908 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3909 err = file_has_perm(cred, file, FILE__WRITE);
3910 break;
3911 }
3912 fallthrough;
3913 case F_SETOWN:
3914 case F_SETSIG:
3915 case F_GETFL:
3916 case F_GETOWN:
3917 case F_GETSIG:
3918 case F_GETOWNER_UIDS:
3919 /* Just check FD__USE permission */
3920 err = file_has_perm(cred, file, 0);
3921 break;
3922 case F_GETLK:
3923 case F_SETLK:
3924 case F_SETLKW:
3925 case F_OFD_GETLK:
3926 case F_OFD_SETLK:
3927 case F_OFD_SETLKW:
3928 #if BITS_PER_LONG == 32
3929 case F_GETLK64:
3930 case F_SETLK64:
3931 case F_SETLKW64:
3932 #endif
3933 err = file_has_perm(cred, file, FILE__LOCK);
3934 break;
3935 }
3936
3937 return err;
3938 }
3939
selinux_file_set_fowner(struct file * file)3940 static void selinux_file_set_fowner(struct file *file)
3941 {
3942 struct file_security_struct *fsec;
3943
3944 fsec = selinux_file(file);
3945 fsec->fown_sid = current_sid();
3946 }
3947
selinux_file_send_sigiotask(struct task_struct * tsk,struct fown_struct * fown,int signum)3948 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3949 struct fown_struct *fown, int signum)
3950 {
3951 struct file *file;
3952 u32 sid = task_sid_obj(tsk);
3953 u32 perm;
3954 struct file_security_struct *fsec;
3955
3956 /* struct fown_struct is never outside the context of a struct file */
3957 file = fown->file;
3958
3959 fsec = selinux_file(file);
3960
3961 if (!signum)
3962 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3963 else
3964 perm = signal_to_av(signum);
3965
3966 return avc_has_perm(fsec->fown_sid, sid,
3967 SECCLASS_PROCESS, perm, NULL);
3968 }
3969
selinux_file_receive(struct file * file)3970 static int selinux_file_receive(struct file *file)
3971 {
3972 const struct cred *cred = current_cred();
3973
3974 return file_has_perm(cred, file, file_to_av(file));
3975 }
3976
selinux_file_open(struct file * file)3977 static int selinux_file_open(struct file *file)
3978 {
3979 struct file_security_struct *fsec;
3980 struct inode_security_struct *isec;
3981
3982 fsec = selinux_file(file);
3983 isec = inode_security(file_inode(file));
3984 /*
3985 * Save inode label and policy sequence number
3986 * at open-time so that selinux_file_permission
3987 * can determine whether revalidation is necessary.
3988 * Task label is already saved in the file security
3989 * struct as its SID.
3990 */
3991 fsec->isid = isec->sid;
3992 fsec->pseqno = avc_policy_seqno();
3993 /*
3994 * Since the inode label or policy seqno may have changed
3995 * between the selinux_inode_permission check and the saving
3996 * of state above, recheck that access is still permitted.
3997 * Otherwise, access might never be revalidated against the
3998 * new inode label or new policy.
3999 * This check is not redundant - do not remove.
4000 */
4001 return file_path_has_perm(file->f_cred, file, open_file_to_av(file));
4002 }
4003
4004 /* task security operations */
4005
selinux_task_alloc(struct task_struct * task,unsigned long clone_flags)4006 static int selinux_task_alloc(struct task_struct *task,
4007 unsigned long clone_flags)
4008 {
4009 u32 sid = current_sid();
4010
4011 return avc_has_perm(sid, sid, SECCLASS_PROCESS, PROCESS__FORK, NULL);
4012 }
4013
4014 /*
4015 * prepare a new set of credentials for modification
4016 */
selinux_cred_prepare(struct cred * new,const struct cred * old,gfp_t gfp)4017 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
4018 gfp_t gfp)
4019 {
4020 const struct task_security_struct *old_tsec = selinux_cred(old);
4021 struct task_security_struct *tsec = selinux_cred(new);
4022
4023 *tsec = *old_tsec;
4024 return 0;
4025 }
4026
4027 /*
4028 * transfer the SELinux data to a blank set of creds
4029 */
selinux_cred_transfer(struct cred * new,const struct cred * old)4030 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
4031 {
4032 const struct task_security_struct *old_tsec = selinux_cred(old);
4033 struct task_security_struct *tsec = selinux_cred(new);
4034
4035 *tsec = *old_tsec;
4036 }
4037
selinux_cred_getsecid(const struct cred * c,u32 * secid)4038 static void selinux_cred_getsecid(const struct cred *c, u32 *secid)
4039 {
4040 *secid = cred_sid(c);
4041 }
4042
4043 /*
4044 * set the security data for a kernel service
4045 * - all the creation contexts are set to unlabelled
4046 */
selinux_kernel_act_as(struct cred * new,u32 secid)4047 static int selinux_kernel_act_as(struct cred *new, u32 secid)
4048 {
4049 struct task_security_struct *tsec = selinux_cred(new);
4050 u32 sid = current_sid();
4051 int ret;
4052
4053 ret = avc_has_perm(sid, secid,
4054 SECCLASS_KERNEL_SERVICE,
4055 KERNEL_SERVICE__USE_AS_OVERRIDE,
4056 NULL);
4057 if (ret == 0) {
4058 tsec->sid = secid;
4059 tsec->create_sid = 0;
4060 tsec->keycreate_sid = 0;
4061 tsec->sockcreate_sid = 0;
4062 }
4063 return ret;
4064 }
4065
4066 /*
4067 * set the file creation context in a security record to the same as the
4068 * objective context of the specified inode
4069 */
selinux_kernel_create_files_as(struct cred * new,struct inode * inode)4070 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
4071 {
4072 struct inode_security_struct *isec = inode_security(inode);
4073 struct task_security_struct *tsec = selinux_cred(new);
4074 u32 sid = current_sid();
4075 int ret;
4076
4077 ret = avc_has_perm(sid, isec->sid,
4078 SECCLASS_KERNEL_SERVICE,
4079 KERNEL_SERVICE__CREATE_FILES_AS,
4080 NULL);
4081
4082 if (ret == 0)
4083 tsec->create_sid = isec->sid;
4084 return ret;
4085 }
4086
selinux_kernel_module_request(char * kmod_name)4087 static int selinux_kernel_module_request(char *kmod_name)
4088 {
4089 struct common_audit_data ad;
4090
4091 ad.type = LSM_AUDIT_DATA_KMOD;
4092 ad.u.kmod_name = kmod_name;
4093
4094 return avc_has_perm(current_sid(), SECINITSID_KERNEL, SECCLASS_SYSTEM,
4095 SYSTEM__MODULE_REQUEST, &ad);
4096 }
4097
selinux_kernel_module_from_file(struct file * file)4098 static int selinux_kernel_module_from_file(struct file *file)
4099 {
4100 struct common_audit_data ad;
4101 struct inode_security_struct *isec;
4102 struct file_security_struct *fsec;
4103 u32 sid = current_sid();
4104 int rc;
4105
4106 /* init_module */
4107 if (file == NULL)
4108 return avc_has_perm(sid, sid, SECCLASS_SYSTEM,
4109 SYSTEM__MODULE_LOAD, NULL);
4110
4111 /* finit_module */
4112
4113 ad.type = LSM_AUDIT_DATA_FILE;
4114 ad.u.file = file;
4115
4116 fsec = selinux_file(file);
4117 if (sid != fsec->sid) {
4118 rc = avc_has_perm(sid, fsec->sid, SECCLASS_FD, FD__USE, &ad);
4119 if (rc)
4120 return rc;
4121 }
4122
4123 isec = inode_security(file_inode(file));
4124 return avc_has_perm(sid, isec->sid, SECCLASS_SYSTEM,
4125 SYSTEM__MODULE_LOAD, &ad);
4126 }
4127
selinux_kernel_read_file(struct file * file,enum kernel_read_file_id id,bool contents)4128 static int selinux_kernel_read_file(struct file *file,
4129 enum kernel_read_file_id id,
4130 bool contents)
4131 {
4132 int rc = 0;
4133
4134 switch (id) {
4135 case READING_MODULE:
4136 rc = selinux_kernel_module_from_file(contents ? file : NULL);
4137 break;
4138 default:
4139 break;
4140 }
4141
4142 return rc;
4143 }
4144
selinux_kernel_load_data(enum kernel_load_data_id id,bool contents)4145 static int selinux_kernel_load_data(enum kernel_load_data_id id, bool contents)
4146 {
4147 int rc = 0;
4148
4149 switch (id) {
4150 case LOADING_MODULE:
4151 rc = selinux_kernel_module_from_file(NULL);
4152 break;
4153 default:
4154 break;
4155 }
4156
4157 return rc;
4158 }
4159
selinux_task_setpgid(struct task_struct * p,pid_t pgid)4160 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
4161 {
4162 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4163 PROCESS__SETPGID, NULL);
4164 }
4165
selinux_task_getpgid(struct task_struct * p)4166 static int selinux_task_getpgid(struct task_struct *p)
4167 {
4168 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4169 PROCESS__GETPGID, NULL);
4170 }
4171
selinux_task_getsid(struct task_struct * p)4172 static int selinux_task_getsid(struct task_struct *p)
4173 {
4174 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4175 PROCESS__GETSESSION, NULL);
4176 }
4177
selinux_current_getsecid_subj(u32 * secid)4178 static void selinux_current_getsecid_subj(u32 *secid)
4179 {
4180 *secid = current_sid();
4181 }
4182
selinux_task_getsecid_obj(struct task_struct * p,u32 * secid)4183 static void selinux_task_getsecid_obj(struct task_struct *p, u32 *secid)
4184 {
4185 *secid = task_sid_obj(p);
4186 }
4187
selinux_task_setnice(struct task_struct * p,int nice)4188 static int selinux_task_setnice(struct task_struct *p, int nice)
4189 {
4190 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4191 PROCESS__SETSCHED, NULL);
4192 }
4193
selinux_task_setioprio(struct task_struct * p,int ioprio)4194 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
4195 {
4196 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4197 PROCESS__SETSCHED, NULL);
4198 }
4199
selinux_task_getioprio(struct task_struct * p)4200 static int selinux_task_getioprio(struct task_struct *p)
4201 {
4202 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4203 PROCESS__GETSCHED, NULL);
4204 }
4205
selinux_task_prlimit(const struct cred * cred,const struct cred * tcred,unsigned int flags)4206 static int selinux_task_prlimit(const struct cred *cred, const struct cred *tcred,
4207 unsigned int flags)
4208 {
4209 u32 av = 0;
4210
4211 if (!flags)
4212 return 0;
4213 if (flags & LSM_PRLIMIT_WRITE)
4214 av |= PROCESS__SETRLIMIT;
4215 if (flags & LSM_PRLIMIT_READ)
4216 av |= PROCESS__GETRLIMIT;
4217 return avc_has_perm(cred_sid(cred), cred_sid(tcred),
4218 SECCLASS_PROCESS, av, NULL);
4219 }
4220
selinux_task_setrlimit(struct task_struct * p,unsigned int resource,struct rlimit * new_rlim)4221 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
4222 struct rlimit *new_rlim)
4223 {
4224 struct rlimit *old_rlim = p->signal->rlim + resource;
4225
4226 /* Control the ability to change the hard limit (whether
4227 lowering or raising it), so that the hard limit can
4228 later be used as a safe reset point for the soft limit
4229 upon context transitions. See selinux_bprm_committing_creds. */
4230 if (old_rlim->rlim_max != new_rlim->rlim_max)
4231 return avc_has_perm(current_sid(), task_sid_obj(p),
4232 SECCLASS_PROCESS, PROCESS__SETRLIMIT, NULL);
4233
4234 return 0;
4235 }
4236
selinux_task_setscheduler(struct task_struct * p)4237 static int selinux_task_setscheduler(struct task_struct *p)
4238 {
4239 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4240 PROCESS__SETSCHED, NULL);
4241 }
4242
selinux_task_getscheduler(struct task_struct * p)4243 static int selinux_task_getscheduler(struct task_struct *p)
4244 {
4245 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4246 PROCESS__GETSCHED, NULL);
4247 }
4248
selinux_task_movememory(struct task_struct * p)4249 static int selinux_task_movememory(struct task_struct *p)
4250 {
4251 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4252 PROCESS__SETSCHED, NULL);
4253 }
4254
selinux_task_kill(struct task_struct * p,struct kernel_siginfo * info,int sig,const struct cred * cred)4255 static int selinux_task_kill(struct task_struct *p, struct kernel_siginfo *info,
4256 int sig, const struct cred *cred)
4257 {
4258 u32 secid;
4259 u32 perm;
4260
4261 if (!sig)
4262 perm = PROCESS__SIGNULL; /* null signal; existence test */
4263 else
4264 perm = signal_to_av(sig);
4265 if (!cred)
4266 secid = current_sid();
4267 else
4268 secid = cred_sid(cred);
4269 return avc_has_perm(secid, task_sid_obj(p), SECCLASS_PROCESS, perm, NULL);
4270 }
4271
selinux_task_to_inode(struct task_struct * p,struct inode * inode)4272 static void selinux_task_to_inode(struct task_struct *p,
4273 struct inode *inode)
4274 {
4275 struct inode_security_struct *isec = selinux_inode(inode);
4276 u32 sid = task_sid_obj(p);
4277
4278 spin_lock(&isec->lock);
4279 isec->sclass = inode_mode_to_security_class(inode->i_mode);
4280 isec->sid = sid;
4281 isec->initialized = LABEL_INITIALIZED;
4282 spin_unlock(&isec->lock);
4283 }
4284
selinux_userns_create(const struct cred * cred)4285 static int selinux_userns_create(const struct cred *cred)
4286 {
4287 u32 sid = current_sid();
4288
4289 return avc_has_perm(sid, sid, SECCLASS_USER_NAMESPACE,
4290 USER_NAMESPACE__CREATE, NULL);
4291 }
4292
4293 /* Returns error only if unable to parse addresses */
selinux_parse_skb_ipv4(struct sk_buff * skb,struct common_audit_data * ad,u8 * proto)4294 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
4295 struct common_audit_data *ad, u8 *proto)
4296 {
4297 int offset, ihlen, ret = -EINVAL;
4298 struct iphdr _iph, *ih;
4299
4300 offset = skb_network_offset(skb);
4301 ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
4302 if (ih == NULL)
4303 goto out;
4304
4305 ihlen = ih->ihl * 4;
4306 if (ihlen < sizeof(_iph))
4307 goto out;
4308
4309 ad->u.net->v4info.saddr = ih->saddr;
4310 ad->u.net->v4info.daddr = ih->daddr;
4311 ret = 0;
4312
4313 if (proto)
4314 *proto = ih->protocol;
4315
4316 switch (ih->protocol) {
4317 case IPPROTO_TCP: {
4318 struct tcphdr _tcph, *th;
4319
4320 if (ntohs(ih->frag_off) & IP_OFFSET)
4321 break;
4322
4323 offset += ihlen;
4324 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4325 if (th == NULL)
4326 break;
4327
4328 ad->u.net->sport = th->source;
4329 ad->u.net->dport = th->dest;
4330 break;
4331 }
4332
4333 case IPPROTO_UDP: {
4334 struct udphdr _udph, *uh;
4335
4336 if (ntohs(ih->frag_off) & IP_OFFSET)
4337 break;
4338
4339 offset += ihlen;
4340 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4341 if (uh == NULL)
4342 break;
4343
4344 ad->u.net->sport = uh->source;
4345 ad->u.net->dport = uh->dest;
4346 break;
4347 }
4348
4349 case IPPROTO_DCCP: {
4350 struct dccp_hdr _dccph, *dh;
4351
4352 if (ntohs(ih->frag_off) & IP_OFFSET)
4353 break;
4354
4355 offset += ihlen;
4356 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4357 if (dh == NULL)
4358 break;
4359
4360 ad->u.net->sport = dh->dccph_sport;
4361 ad->u.net->dport = dh->dccph_dport;
4362 break;
4363 }
4364
4365 #if IS_ENABLED(CONFIG_IP_SCTP)
4366 case IPPROTO_SCTP: {
4367 struct sctphdr _sctph, *sh;
4368
4369 if (ntohs(ih->frag_off) & IP_OFFSET)
4370 break;
4371
4372 offset += ihlen;
4373 sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
4374 if (sh == NULL)
4375 break;
4376
4377 ad->u.net->sport = sh->source;
4378 ad->u.net->dport = sh->dest;
4379 break;
4380 }
4381 #endif
4382 default:
4383 break;
4384 }
4385 out:
4386 return ret;
4387 }
4388
4389 #if IS_ENABLED(CONFIG_IPV6)
4390
4391 /* Returns error only if unable to parse addresses */
selinux_parse_skb_ipv6(struct sk_buff * skb,struct common_audit_data * ad,u8 * proto)4392 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
4393 struct common_audit_data *ad, u8 *proto)
4394 {
4395 u8 nexthdr;
4396 int ret = -EINVAL, offset;
4397 struct ipv6hdr _ipv6h, *ip6;
4398 __be16 frag_off;
4399
4400 offset = skb_network_offset(skb);
4401 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
4402 if (ip6 == NULL)
4403 goto out;
4404
4405 ad->u.net->v6info.saddr = ip6->saddr;
4406 ad->u.net->v6info.daddr = ip6->daddr;
4407 ret = 0;
4408
4409 nexthdr = ip6->nexthdr;
4410 offset += sizeof(_ipv6h);
4411 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
4412 if (offset < 0)
4413 goto out;
4414
4415 if (proto)
4416 *proto = nexthdr;
4417
4418 switch (nexthdr) {
4419 case IPPROTO_TCP: {
4420 struct tcphdr _tcph, *th;
4421
4422 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4423 if (th == NULL)
4424 break;
4425
4426 ad->u.net->sport = th->source;
4427 ad->u.net->dport = th->dest;
4428 break;
4429 }
4430
4431 case IPPROTO_UDP: {
4432 struct udphdr _udph, *uh;
4433
4434 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4435 if (uh == NULL)
4436 break;
4437
4438 ad->u.net->sport = uh->source;
4439 ad->u.net->dport = uh->dest;
4440 break;
4441 }
4442
4443 case IPPROTO_DCCP: {
4444 struct dccp_hdr _dccph, *dh;
4445
4446 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4447 if (dh == NULL)
4448 break;
4449
4450 ad->u.net->sport = dh->dccph_sport;
4451 ad->u.net->dport = dh->dccph_dport;
4452 break;
4453 }
4454
4455 #if IS_ENABLED(CONFIG_IP_SCTP)
4456 case IPPROTO_SCTP: {
4457 struct sctphdr _sctph, *sh;
4458
4459 sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
4460 if (sh == NULL)
4461 break;
4462
4463 ad->u.net->sport = sh->source;
4464 ad->u.net->dport = sh->dest;
4465 break;
4466 }
4467 #endif
4468 /* includes fragments */
4469 default:
4470 break;
4471 }
4472 out:
4473 return ret;
4474 }
4475
4476 #endif /* IPV6 */
4477
selinux_parse_skb(struct sk_buff * skb,struct common_audit_data * ad,char ** _addrp,int src,u8 * proto)4478 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
4479 char **_addrp, int src, u8 *proto)
4480 {
4481 char *addrp;
4482 int ret;
4483
4484 switch (ad->u.net->family) {
4485 case PF_INET:
4486 ret = selinux_parse_skb_ipv4(skb, ad, proto);
4487 if (ret)
4488 goto parse_error;
4489 addrp = (char *)(src ? &ad->u.net->v4info.saddr :
4490 &ad->u.net->v4info.daddr);
4491 goto okay;
4492
4493 #if IS_ENABLED(CONFIG_IPV6)
4494 case PF_INET6:
4495 ret = selinux_parse_skb_ipv6(skb, ad, proto);
4496 if (ret)
4497 goto parse_error;
4498 addrp = (char *)(src ? &ad->u.net->v6info.saddr :
4499 &ad->u.net->v6info.daddr);
4500 goto okay;
4501 #endif /* IPV6 */
4502 default:
4503 addrp = NULL;
4504 goto okay;
4505 }
4506
4507 parse_error:
4508 pr_warn(
4509 "SELinux: failure in selinux_parse_skb(),"
4510 " unable to parse packet\n");
4511 return ret;
4512
4513 okay:
4514 if (_addrp)
4515 *_addrp = addrp;
4516 return 0;
4517 }
4518
4519 /**
4520 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
4521 * @skb: the packet
4522 * @family: protocol family
4523 * @sid: the packet's peer label SID
4524 *
4525 * Description:
4526 * Check the various different forms of network peer labeling and determine
4527 * the peer label/SID for the packet; most of the magic actually occurs in
4528 * the security server function security_net_peersid_cmp(). The function
4529 * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
4530 * or -EACCES if @sid is invalid due to inconsistencies with the different
4531 * peer labels.
4532 *
4533 */
selinux_skb_peerlbl_sid(struct sk_buff * skb,u16 family,u32 * sid)4534 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
4535 {
4536 int err;
4537 u32 xfrm_sid;
4538 u32 nlbl_sid;
4539 u32 nlbl_type;
4540
4541 err = selinux_xfrm_skb_sid(skb, &xfrm_sid);
4542 if (unlikely(err))
4543 return -EACCES;
4544 err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
4545 if (unlikely(err))
4546 return -EACCES;
4547
4548 err = security_net_peersid_resolve(nlbl_sid,
4549 nlbl_type, xfrm_sid, sid);
4550 if (unlikely(err)) {
4551 pr_warn(
4552 "SELinux: failure in selinux_skb_peerlbl_sid(),"
4553 " unable to determine packet's peer label\n");
4554 return -EACCES;
4555 }
4556
4557 return 0;
4558 }
4559
4560 /**
4561 * selinux_conn_sid - Determine the child socket label for a connection
4562 * @sk_sid: the parent socket's SID
4563 * @skb_sid: the packet's SID
4564 * @conn_sid: the resulting connection SID
4565 *
4566 * If @skb_sid is valid then the user:role:type information from @sk_sid is
4567 * combined with the MLS information from @skb_sid in order to create
4568 * @conn_sid. If @skb_sid is not valid then @conn_sid is simply a copy
4569 * of @sk_sid. Returns zero on success, negative values on failure.
4570 *
4571 */
selinux_conn_sid(u32 sk_sid,u32 skb_sid,u32 * conn_sid)4572 static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid)
4573 {
4574 int err = 0;
4575
4576 if (skb_sid != SECSID_NULL)
4577 err = security_sid_mls_copy(sk_sid, skb_sid,
4578 conn_sid);
4579 else
4580 *conn_sid = sk_sid;
4581
4582 return err;
4583 }
4584
4585 /* socket security operations */
4586
socket_sockcreate_sid(const struct task_security_struct * tsec,u16 secclass,u32 * socksid)4587 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
4588 u16 secclass, u32 *socksid)
4589 {
4590 if (tsec->sockcreate_sid > SECSID_NULL) {
4591 *socksid = tsec->sockcreate_sid;
4592 return 0;
4593 }
4594
4595 return security_transition_sid(tsec->sid, tsec->sid,
4596 secclass, NULL, socksid);
4597 }
4598
sock_has_perm(struct sock * sk,u32 perms)4599 static int sock_has_perm(struct sock *sk, u32 perms)
4600 {
4601 struct sk_security_struct *sksec = selinux_sock(sk);
4602 struct common_audit_data ad;
4603 struct lsm_network_audit net;
4604
4605 if (sksec->sid == SECINITSID_KERNEL)
4606 return 0;
4607
4608 /*
4609 * Before POLICYDB_CAP_USERSPACE_INITIAL_CONTEXT, sockets that
4610 * inherited the kernel context from early boot used to be skipped
4611 * here, so preserve that behavior unless the capability is set.
4612 *
4613 * By setting the capability the policy signals that it is ready
4614 * for this quirk to be fixed. Note that sockets created by a kernel
4615 * thread or a usermode helper executed without a transition will
4616 * still be skipped in this check regardless of the policycap
4617 * setting.
4618 */
4619 if (!selinux_policycap_userspace_initial_context() &&
4620 sksec->sid == SECINITSID_INIT)
4621 return 0;
4622
4623 ad_net_init_from_sk(&ad, &net, sk);
4624
4625 return avc_has_perm(current_sid(), sksec->sid, sksec->sclass, perms,
4626 &ad);
4627 }
4628
selinux_socket_create(int family,int type,int protocol,int kern)4629 static int selinux_socket_create(int family, int type,
4630 int protocol, int kern)
4631 {
4632 const struct task_security_struct *tsec = selinux_cred(current_cred());
4633 u32 newsid;
4634 u16 secclass;
4635 int rc;
4636
4637 if (kern)
4638 return 0;
4639
4640 secclass = socket_type_to_security_class(family, type, protocol);
4641 rc = socket_sockcreate_sid(tsec, secclass, &newsid);
4642 if (rc)
4643 return rc;
4644
4645 return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
4646 }
4647
selinux_socket_post_create(struct socket * sock,int family,int type,int protocol,int kern)4648 static int selinux_socket_post_create(struct socket *sock, int family,
4649 int type, int protocol, int kern)
4650 {
4651 const struct task_security_struct *tsec = selinux_cred(current_cred());
4652 struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
4653 struct sk_security_struct *sksec;
4654 u16 sclass = socket_type_to_security_class(family, type, protocol);
4655 u32 sid = SECINITSID_KERNEL;
4656 int err = 0;
4657
4658 if (!kern) {
4659 err = socket_sockcreate_sid(tsec, sclass, &sid);
4660 if (err)
4661 return err;
4662 }
4663
4664 isec->sclass = sclass;
4665 isec->sid = sid;
4666 isec->initialized = LABEL_INITIALIZED;
4667
4668 if (sock->sk) {
4669 sksec = selinux_sock(sock->sk);
4670 sksec->sclass = sclass;
4671 sksec->sid = sid;
4672 /* Allows detection of the first association on this socket */
4673 if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4674 sksec->sctp_assoc_state = SCTP_ASSOC_UNSET;
4675
4676 err = selinux_netlbl_socket_post_create(sock->sk, family);
4677 }
4678
4679 return err;
4680 }
4681
selinux_socket_socketpair(struct socket * socka,struct socket * sockb)4682 static int selinux_socket_socketpair(struct socket *socka,
4683 struct socket *sockb)
4684 {
4685 struct sk_security_struct *sksec_a = selinux_sock(socka->sk);
4686 struct sk_security_struct *sksec_b = selinux_sock(sockb->sk);
4687
4688 sksec_a->peer_sid = sksec_b->sid;
4689 sksec_b->peer_sid = sksec_a->sid;
4690
4691 return 0;
4692 }
4693
4694 /* Range of port numbers used to automatically bind.
4695 Need to determine whether we should perform a name_bind
4696 permission check between the socket and the port number. */
4697
selinux_socket_bind(struct socket * sock,struct sockaddr * address,int addrlen)4698 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
4699 {
4700 struct sock *sk = sock->sk;
4701 struct sk_security_struct *sksec = selinux_sock(sk);
4702 u16 family;
4703 int err;
4704
4705 err = sock_has_perm(sk, SOCKET__BIND);
4706 if (err)
4707 goto out;
4708
4709 /* If PF_INET or PF_INET6, check name_bind permission for the port. */
4710 family = sk->sk_family;
4711 if (family == PF_INET || family == PF_INET6) {
4712 char *addrp;
4713 struct common_audit_data ad;
4714 struct lsm_network_audit net = {0,};
4715 struct sockaddr_in *addr4 = NULL;
4716 struct sockaddr_in6 *addr6 = NULL;
4717 u16 family_sa;
4718 unsigned short snum;
4719 u32 sid, node_perm;
4720
4721 /*
4722 * sctp_bindx(3) calls via selinux_sctp_bind_connect()
4723 * that validates multiple binding addresses. Because of this
4724 * need to check address->sa_family as it is possible to have
4725 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
4726 */
4727 if (addrlen < offsetofend(struct sockaddr, sa_family))
4728 return -EINVAL;
4729 family_sa = address->sa_family;
4730 switch (family_sa) {
4731 case AF_UNSPEC:
4732 case AF_INET:
4733 if (addrlen < sizeof(struct sockaddr_in))
4734 return -EINVAL;
4735 addr4 = (struct sockaddr_in *)address;
4736 if (family_sa == AF_UNSPEC) {
4737 if (family == PF_INET6) {
4738 /* Length check from inet6_bind_sk() */
4739 if (addrlen < SIN6_LEN_RFC2133)
4740 return -EINVAL;
4741 /* Family check from __inet6_bind() */
4742 goto err_af;
4743 }
4744 /* see __inet_bind(), we only want to allow
4745 * AF_UNSPEC if the address is INADDR_ANY
4746 */
4747 if (addr4->sin_addr.s_addr != htonl(INADDR_ANY))
4748 goto err_af;
4749 family_sa = AF_INET;
4750 }
4751 snum = ntohs(addr4->sin_port);
4752 addrp = (char *)&addr4->sin_addr.s_addr;
4753 break;
4754 case AF_INET6:
4755 if (addrlen < SIN6_LEN_RFC2133)
4756 return -EINVAL;
4757 addr6 = (struct sockaddr_in6 *)address;
4758 snum = ntohs(addr6->sin6_port);
4759 addrp = (char *)&addr6->sin6_addr.s6_addr;
4760 break;
4761 default:
4762 goto err_af;
4763 }
4764
4765 ad.type = LSM_AUDIT_DATA_NET;
4766 ad.u.net = &net;
4767 ad.u.net->sport = htons(snum);
4768 ad.u.net->family = family_sa;
4769
4770 if (snum) {
4771 int low, high;
4772
4773 inet_get_local_port_range(sock_net(sk), &low, &high);
4774
4775 if (inet_port_requires_bind_service(sock_net(sk), snum) ||
4776 snum < low || snum > high) {
4777 err = sel_netport_sid(sk->sk_protocol,
4778 snum, &sid);
4779 if (err)
4780 goto out;
4781 err = avc_has_perm(sksec->sid, sid,
4782 sksec->sclass,
4783 SOCKET__NAME_BIND, &ad);
4784 if (err)
4785 goto out;
4786 }
4787 }
4788
4789 switch (sksec->sclass) {
4790 case SECCLASS_TCP_SOCKET:
4791 node_perm = TCP_SOCKET__NODE_BIND;
4792 break;
4793
4794 case SECCLASS_UDP_SOCKET:
4795 node_perm = UDP_SOCKET__NODE_BIND;
4796 break;
4797
4798 case SECCLASS_DCCP_SOCKET:
4799 node_perm = DCCP_SOCKET__NODE_BIND;
4800 break;
4801
4802 case SECCLASS_SCTP_SOCKET:
4803 node_perm = SCTP_SOCKET__NODE_BIND;
4804 break;
4805
4806 default:
4807 node_perm = RAWIP_SOCKET__NODE_BIND;
4808 break;
4809 }
4810
4811 err = sel_netnode_sid(addrp, family_sa, &sid);
4812 if (err)
4813 goto out;
4814
4815 if (family_sa == AF_INET)
4816 ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
4817 else
4818 ad.u.net->v6info.saddr = addr6->sin6_addr;
4819
4820 err = avc_has_perm(sksec->sid, sid,
4821 sksec->sclass, node_perm, &ad);
4822 if (err)
4823 goto out;
4824 }
4825 out:
4826 return err;
4827 err_af:
4828 /* Note that SCTP services expect -EINVAL, others -EAFNOSUPPORT. */
4829 if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4830 return -EINVAL;
4831 return -EAFNOSUPPORT;
4832 }
4833
4834 /* This supports connect(2) and SCTP connect services such as sctp_connectx(3)
4835 * and sctp_sendmsg(3) as described in Documentation/security/SCTP.rst
4836 */
selinux_socket_connect_helper(struct socket * sock,struct sockaddr * address,int addrlen)4837 static int selinux_socket_connect_helper(struct socket *sock,
4838 struct sockaddr *address, int addrlen)
4839 {
4840 struct sock *sk = sock->sk;
4841 struct sk_security_struct *sksec = selinux_sock(sk);
4842 int err;
4843
4844 err = sock_has_perm(sk, SOCKET__CONNECT);
4845 if (err)
4846 return err;
4847 if (addrlen < offsetofend(struct sockaddr, sa_family))
4848 return -EINVAL;
4849
4850 /* connect(AF_UNSPEC) has special handling, as it is a documented
4851 * way to disconnect the socket
4852 */
4853 if (address->sa_family == AF_UNSPEC)
4854 return 0;
4855
4856 /*
4857 * If a TCP, DCCP or SCTP socket, check name_connect permission
4858 * for the port.
4859 */
4860 if (sksec->sclass == SECCLASS_TCP_SOCKET ||
4861 sksec->sclass == SECCLASS_DCCP_SOCKET ||
4862 sksec->sclass == SECCLASS_SCTP_SOCKET) {
4863 struct common_audit_data ad;
4864 struct lsm_network_audit net = {0,};
4865 struct sockaddr_in *addr4 = NULL;
4866 struct sockaddr_in6 *addr6 = NULL;
4867 unsigned short snum;
4868 u32 sid, perm;
4869
4870 /* sctp_connectx(3) calls via selinux_sctp_bind_connect()
4871 * that validates multiple connect addresses. Because of this
4872 * need to check address->sa_family as it is possible to have
4873 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
4874 */
4875 switch (address->sa_family) {
4876 case AF_INET:
4877 addr4 = (struct sockaddr_in *)address;
4878 if (addrlen < sizeof(struct sockaddr_in))
4879 return -EINVAL;
4880 snum = ntohs(addr4->sin_port);
4881 break;
4882 case AF_INET6:
4883 addr6 = (struct sockaddr_in6 *)address;
4884 if (addrlen < SIN6_LEN_RFC2133)
4885 return -EINVAL;
4886 snum = ntohs(addr6->sin6_port);
4887 break;
4888 default:
4889 /* Note that SCTP services expect -EINVAL, whereas
4890 * others expect -EAFNOSUPPORT.
4891 */
4892 if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4893 return -EINVAL;
4894 else
4895 return -EAFNOSUPPORT;
4896 }
4897
4898 err = sel_netport_sid(sk->sk_protocol, snum, &sid);
4899 if (err)
4900 return err;
4901
4902 switch (sksec->sclass) {
4903 case SECCLASS_TCP_SOCKET:
4904 perm = TCP_SOCKET__NAME_CONNECT;
4905 break;
4906 case SECCLASS_DCCP_SOCKET:
4907 perm = DCCP_SOCKET__NAME_CONNECT;
4908 break;
4909 case SECCLASS_SCTP_SOCKET:
4910 perm = SCTP_SOCKET__NAME_CONNECT;
4911 break;
4912 }
4913
4914 ad.type = LSM_AUDIT_DATA_NET;
4915 ad.u.net = &net;
4916 ad.u.net->dport = htons(snum);
4917 ad.u.net->family = address->sa_family;
4918 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
4919 if (err)
4920 return err;
4921 }
4922
4923 return 0;
4924 }
4925
4926 /* Supports connect(2), see comments in selinux_socket_connect_helper() */
selinux_socket_connect(struct socket * sock,struct sockaddr * address,int addrlen)4927 static int selinux_socket_connect(struct socket *sock,
4928 struct sockaddr *address, int addrlen)
4929 {
4930 int err;
4931 struct sock *sk = sock->sk;
4932
4933 err = selinux_socket_connect_helper(sock, address, addrlen);
4934 if (err)
4935 return err;
4936
4937 return selinux_netlbl_socket_connect(sk, address);
4938 }
4939
selinux_socket_listen(struct socket * sock,int backlog)4940 static int selinux_socket_listen(struct socket *sock, int backlog)
4941 {
4942 return sock_has_perm(sock->sk, SOCKET__LISTEN);
4943 }
4944
selinux_socket_accept(struct socket * sock,struct socket * newsock)4945 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
4946 {
4947 int err;
4948 struct inode_security_struct *isec;
4949 struct inode_security_struct *newisec;
4950 u16 sclass;
4951 u32 sid;
4952
4953 err = sock_has_perm(sock->sk, SOCKET__ACCEPT);
4954 if (err)
4955 return err;
4956
4957 isec = inode_security_novalidate(SOCK_INODE(sock));
4958 spin_lock(&isec->lock);
4959 sclass = isec->sclass;
4960 sid = isec->sid;
4961 spin_unlock(&isec->lock);
4962
4963 newisec = inode_security_novalidate(SOCK_INODE(newsock));
4964 newisec->sclass = sclass;
4965 newisec->sid = sid;
4966 newisec->initialized = LABEL_INITIALIZED;
4967
4968 return 0;
4969 }
4970
selinux_socket_sendmsg(struct socket * sock,struct msghdr * msg,int size)4971 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4972 int size)
4973 {
4974 return sock_has_perm(sock->sk, SOCKET__WRITE);
4975 }
4976
selinux_socket_recvmsg(struct socket * sock,struct msghdr * msg,int size,int flags)4977 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
4978 int size, int flags)
4979 {
4980 return sock_has_perm(sock->sk, SOCKET__READ);
4981 }
4982
selinux_socket_getsockname(struct socket * sock)4983 static int selinux_socket_getsockname(struct socket *sock)
4984 {
4985 return sock_has_perm(sock->sk, SOCKET__GETATTR);
4986 }
4987
selinux_socket_getpeername(struct socket * sock)4988 static int selinux_socket_getpeername(struct socket *sock)
4989 {
4990 return sock_has_perm(sock->sk, SOCKET__GETATTR);
4991 }
4992
selinux_socket_setsockopt(struct socket * sock,int level,int optname)4993 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
4994 {
4995 int err;
4996
4997 err = sock_has_perm(sock->sk, SOCKET__SETOPT);
4998 if (err)
4999 return err;
5000
5001 return selinux_netlbl_socket_setsockopt(sock, level, optname);
5002 }
5003
selinux_socket_getsockopt(struct socket * sock,int level,int optname)5004 static int selinux_socket_getsockopt(struct socket *sock, int level,
5005 int optname)
5006 {
5007 return sock_has_perm(sock->sk, SOCKET__GETOPT);
5008 }
5009
selinux_socket_shutdown(struct socket * sock,int how)5010 static int selinux_socket_shutdown(struct socket *sock, int how)
5011 {
5012 return sock_has_perm(sock->sk, SOCKET__SHUTDOWN);
5013 }
5014
selinux_socket_unix_stream_connect(struct sock * sock,struct sock * other,struct sock * newsk)5015 static int selinux_socket_unix_stream_connect(struct sock *sock,
5016 struct sock *other,
5017 struct sock *newsk)
5018 {
5019 struct sk_security_struct *sksec_sock = selinux_sock(sock);
5020 struct sk_security_struct *sksec_other = selinux_sock(other);
5021 struct sk_security_struct *sksec_new = selinux_sock(newsk);
5022 struct common_audit_data ad;
5023 struct lsm_network_audit net;
5024 int err;
5025
5026 ad_net_init_from_sk(&ad, &net, other);
5027
5028 err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
5029 sksec_other->sclass,
5030 UNIX_STREAM_SOCKET__CONNECTTO, &ad);
5031 if (err)
5032 return err;
5033
5034 /* server child socket */
5035 sksec_new->peer_sid = sksec_sock->sid;
5036 err = security_sid_mls_copy(sksec_other->sid,
5037 sksec_sock->sid, &sksec_new->sid);
5038 if (err)
5039 return err;
5040
5041 /* connecting socket */
5042 sksec_sock->peer_sid = sksec_new->sid;
5043
5044 return 0;
5045 }
5046
selinux_socket_unix_may_send(struct socket * sock,struct socket * other)5047 static int selinux_socket_unix_may_send(struct socket *sock,
5048 struct socket *other)
5049 {
5050 struct sk_security_struct *ssec = selinux_sock(sock->sk);
5051 struct sk_security_struct *osec = selinux_sock(other->sk);
5052 struct common_audit_data ad;
5053 struct lsm_network_audit net;
5054
5055 ad_net_init_from_sk(&ad, &net, other->sk);
5056
5057 return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
5058 &ad);
5059 }
5060
selinux_inet_sys_rcv_skb(struct net * ns,int ifindex,char * addrp,u16 family,u32 peer_sid,struct common_audit_data * ad)5061 static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
5062 char *addrp, u16 family, u32 peer_sid,
5063 struct common_audit_data *ad)
5064 {
5065 int err;
5066 u32 if_sid;
5067 u32 node_sid;
5068
5069 err = sel_netif_sid(ns, ifindex, &if_sid);
5070 if (err)
5071 return err;
5072 err = avc_has_perm(peer_sid, if_sid,
5073 SECCLASS_NETIF, NETIF__INGRESS, ad);
5074 if (err)
5075 return err;
5076
5077 err = sel_netnode_sid(addrp, family, &node_sid);
5078 if (err)
5079 return err;
5080 return avc_has_perm(peer_sid, node_sid,
5081 SECCLASS_NODE, NODE__RECVFROM, ad);
5082 }
5083
selinux_sock_rcv_skb_compat(struct sock * sk,struct sk_buff * skb,u16 family)5084 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
5085 u16 family)
5086 {
5087 int err = 0;
5088 struct sk_security_struct *sksec = selinux_sock(sk);
5089 u32 sk_sid = sksec->sid;
5090 struct common_audit_data ad;
5091 struct lsm_network_audit net;
5092 char *addrp;
5093
5094 ad_net_init_from_iif(&ad, &net, skb->skb_iif, family);
5095 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
5096 if (err)
5097 return err;
5098
5099 if (selinux_secmark_enabled()) {
5100 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
5101 PACKET__RECV, &ad);
5102 if (err)
5103 return err;
5104 }
5105
5106 err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
5107 if (err)
5108 return err;
5109 err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
5110
5111 return err;
5112 }
5113
selinux_socket_sock_rcv_skb(struct sock * sk,struct sk_buff * skb)5114 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
5115 {
5116 int err, peerlbl_active, secmark_active;
5117 struct sk_security_struct *sksec = selinux_sock(sk);
5118 u16 family = sk->sk_family;
5119 u32 sk_sid = sksec->sid;
5120 struct common_audit_data ad;
5121 struct lsm_network_audit net;
5122 char *addrp;
5123
5124 if (family != PF_INET && family != PF_INET6)
5125 return 0;
5126
5127 /* Handle mapped IPv4 packets arriving via IPv6 sockets */
5128 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5129 family = PF_INET;
5130
5131 /* If any sort of compatibility mode is enabled then handoff processing
5132 * to the selinux_sock_rcv_skb_compat() function to deal with the
5133 * special handling. We do this in an attempt to keep this function
5134 * as fast and as clean as possible. */
5135 if (!selinux_policycap_netpeer())
5136 return selinux_sock_rcv_skb_compat(sk, skb, family);
5137
5138 secmark_active = selinux_secmark_enabled();
5139 peerlbl_active = selinux_peerlbl_enabled();
5140 if (!secmark_active && !peerlbl_active)
5141 return 0;
5142
5143 ad_net_init_from_iif(&ad, &net, skb->skb_iif, family);
5144 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
5145 if (err)
5146 return err;
5147
5148 if (peerlbl_active) {
5149 u32 peer_sid;
5150
5151 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
5152 if (err)
5153 return err;
5154 err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
5155 addrp, family, peer_sid, &ad);
5156 if (err) {
5157 selinux_netlbl_err(skb, family, err, 0);
5158 return err;
5159 }
5160 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
5161 PEER__RECV, &ad);
5162 if (err) {
5163 selinux_netlbl_err(skb, family, err, 0);
5164 return err;
5165 }
5166 }
5167
5168 if (secmark_active) {
5169 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
5170 PACKET__RECV, &ad);
5171 if (err)
5172 return err;
5173 }
5174
5175 return err;
5176 }
5177
selinux_socket_getpeersec_stream(struct socket * sock,sockptr_t optval,sockptr_t optlen,unsigned int len)5178 static int selinux_socket_getpeersec_stream(struct socket *sock,
5179 sockptr_t optval, sockptr_t optlen,
5180 unsigned int len)
5181 {
5182 int err = 0;
5183 char *scontext = NULL;
5184 u32 scontext_len;
5185 struct sk_security_struct *sksec = selinux_sock(sock->sk);
5186 u32 peer_sid = SECSID_NULL;
5187
5188 if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
5189 sksec->sclass == SECCLASS_TCP_SOCKET ||
5190 sksec->sclass == SECCLASS_SCTP_SOCKET)
5191 peer_sid = sksec->peer_sid;
5192 if (peer_sid == SECSID_NULL)
5193 return -ENOPROTOOPT;
5194
5195 err = security_sid_to_context(peer_sid, &scontext,
5196 &scontext_len);
5197 if (err)
5198 return err;
5199 if (scontext_len > len) {
5200 err = -ERANGE;
5201 goto out_len;
5202 }
5203
5204 if (copy_to_sockptr(optval, scontext, scontext_len))
5205 err = -EFAULT;
5206 out_len:
5207 if (copy_to_sockptr(optlen, &scontext_len, sizeof(scontext_len)))
5208 err = -EFAULT;
5209 kfree(scontext);
5210 return err;
5211 }
5212
selinux_socket_getpeersec_dgram(struct socket * sock,struct sk_buff * skb,u32 * secid)5213 static int selinux_socket_getpeersec_dgram(struct socket *sock,
5214 struct sk_buff *skb, u32 *secid)
5215 {
5216 u32 peer_secid = SECSID_NULL;
5217 u16 family;
5218
5219 if (skb && skb->protocol == htons(ETH_P_IP))
5220 family = PF_INET;
5221 else if (skb && skb->protocol == htons(ETH_P_IPV6))
5222 family = PF_INET6;
5223 else if (sock)
5224 family = sock->sk->sk_family;
5225 else {
5226 *secid = SECSID_NULL;
5227 return -EINVAL;
5228 }
5229
5230 if (sock && family == PF_UNIX) {
5231 struct inode_security_struct *isec;
5232 isec = inode_security_novalidate(SOCK_INODE(sock));
5233 peer_secid = isec->sid;
5234 } else if (skb)
5235 selinux_skb_peerlbl_sid(skb, family, &peer_secid);
5236
5237 *secid = peer_secid;
5238 if (peer_secid == SECSID_NULL)
5239 return -ENOPROTOOPT;
5240 return 0;
5241 }
5242
selinux_sk_alloc_security(struct sock * sk,int family,gfp_t priority)5243 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
5244 {
5245 struct sk_security_struct *sksec = selinux_sock(sk);
5246
5247 sksec->peer_sid = SECINITSID_UNLABELED;
5248 sksec->sid = SECINITSID_UNLABELED;
5249 sksec->sclass = SECCLASS_SOCKET;
5250 selinux_netlbl_sk_security_reset(sksec);
5251
5252 return 0;
5253 }
5254
selinux_sk_free_security(struct sock * sk)5255 static void selinux_sk_free_security(struct sock *sk)
5256 {
5257 struct sk_security_struct *sksec = selinux_sock(sk);
5258
5259 selinux_netlbl_sk_security_free(sksec);
5260 }
5261
selinux_sk_clone_security(const struct sock * sk,struct sock * newsk)5262 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
5263 {
5264 struct sk_security_struct *sksec = selinux_sock(sk);
5265 struct sk_security_struct *newsksec = selinux_sock(newsk);
5266
5267 newsksec->sid = sksec->sid;
5268 newsksec->peer_sid = sksec->peer_sid;
5269 newsksec->sclass = sksec->sclass;
5270
5271 selinux_netlbl_sk_security_reset(newsksec);
5272 }
5273
selinux_sk_getsecid(const struct sock * sk,u32 * secid)5274 static void selinux_sk_getsecid(const struct sock *sk, u32 *secid)
5275 {
5276 if (!sk)
5277 *secid = SECINITSID_ANY_SOCKET;
5278 else {
5279 const struct sk_security_struct *sksec = selinux_sock(sk);
5280
5281 *secid = sksec->sid;
5282 }
5283 }
5284
selinux_sock_graft(struct sock * sk,struct socket * parent)5285 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
5286 {
5287 struct inode_security_struct *isec =
5288 inode_security_novalidate(SOCK_INODE(parent));
5289 struct sk_security_struct *sksec = selinux_sock(sk);
5290
5291 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
5292 sk->sk_family == PF_UNIX)
5293 isec->sid = sksec->sid;
5294 sksec->sclass = isec->sclass;
5295 }
5296
5297 /*
5298 * Determines peer_secid for the asoc and updates socket's peer label
5299 * if it's the first association on the socket.
5300 */
selinux_sctp_process_new_assoc(struct sctp_association * asoc,struct sk_buff * skb)5301 static int selinux_sctp_process_new_assoc(struct sctp_association *asoc,
5302 struct sk_buff *skb)
5303 {
5304 struct sock *sk = asoc->base.sk;
5305 u16 family = sk->sk_family;
5306 struct sk_security_struct *sksec = selinux_sock(sk);
5307 struct common_audit_data ad;
5308 struct lsm_network_audit net;
5309 int err;
5310
5311 /* handle mapped IPv4 packets arriving via IPv6 sockets */
5312 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5313 family = PF_INET;
5314
5315 if (selinux_peerlbl_enabled()) {
5316 asoc->peer_secid = SECSID_NULL;
5317
5318 /* This will return peer_sid = SECSID_NULL if there are
5319 * no peer labels, see security_net_peersid_resolve().
5320 */
5321 err = selinux_skb_peerlbl_sid(skb, family, &asoc->peer_secid);
5322 if (err)
5323 return err;
5324
5325 if (asoc->peer_secid == SECSID_NULL)
5326 asoc->peer_secid = SECINITSID_UNLABELED;
5327 } else {
5328 asoc->peer_secid = SECINITSID_UNLABELED;
5329 }
5330
5331 if (sksec->sctp_assoc_state == SCTP_ASSOC_UNSET) {
5332 sksec->sctp_assoc_state = SCTP_ASSOC_SET;
5333
5334 /* Here as first association on socket. As the peer SID
5335 * was allowed by peer recv (and the netif/node checks),
5336 * then it is approved by policy and used as the primary
5337 * peer SID for getpeercon(3).
5338 */
5339 sksec->peer_sid = asoc->peer_secid;
5340 } else if (sksec->peer_sid != asoc->peer_secid) {
5341 /* Other association peer SIDs are checked to enforce
5342 * consistency among the peer SIDs.
5343 */
5344 ad_net_init_from_sk(&ad, &net, asoc->base.sk);
5345 err = avc_has_perm(sksec->peer_sid, asoc->peer_secid,
5346 sksec->sclass, SCTP_SOCKET__ASSOCIATION,
5347 &ad);
5348 if (err)
5349 return err;
5350 }
5351 return 0;
5352 }
5353
5354 /* Called whenever SCTP receives an INIT or COOKIE ECHO chunk. This
5355 * happens on an incoming connect(2), sctp_connectx(3) or
5356 * sctp_sendmsg(3) (with no association already present).
5357 */
selinux_sctp_assoc_request(struct sctp_association * asoc,struct sk_buff * skb)5358 static int selinux_sctp_assoc_request(struct sctp_association *asoc,
5359 struct sk_buff *skb)
5360 {
5361 struct sk_security_struct *sksec = selinux_sock(asoc->base.sk);
5362 u32 conn_sid;
5363 int err;
5364
5365 if (!selinux_policycap_extsockclass())
5366 return 0;
5367
5368 err = selinux_sctp_process_new_assoc(asoc, skb);
5369 if (err)
5370 return err;
5371
5372 /* Compute the MLS component for the connection and store
5373 * the information in asoc. This will be used by SCTP TCP type
5374 * sockets and peeled off connections as they cause a new
5375 * socket to be generated. selinux_sctp_sk_clone() will then
5376 * plug this into the new socket.
5377 */
5378 err = selinux_conn_sid(sksec->sid, asoc->peer_secid, &conn_sid);
5379 if (err)
5380 return err;
5381
5382 asoc->secid = conn_sid;
5383
5384 /* Set any NetLabel labels including CIPSO/CALIPSO options. */
5385 return selinux_netlbl_sctp_assoc_request(asoc, skb);
5386 }
5387
5388 /* Called when SCTP receives a COOKIE ACK chunk as the final
5389 * response to an association request (initited by us).
5390 */
selinux_sctp_assoc_established(struct sctp_association * asoc,struct sk_buff * skb)5391 static int selinux_sctp_assoc_established(struct sctp_association *asoc,
5392 struct sk_buff *skb)
5393 {
5394 struct sk_security_struct *sksec = selinux_sock(asoc->base.sk);
5395
5396 if (!selinux_policycap_extsockclass())
5397 return 0;
5398
5399 /* Inherit secid from the parent socket - this will be picked up
5400 * by selinux_sctp_sk_clone() if the association gets peeled off
5401 * into a new socket.
5402 */
5403 asoc->secid = sksec->sid;
5404
5405 return selinux_sctp_process_new_assoc(asoc, skb);
5406 }
5407
5408 /* Check if sctp IPv4/IPv6 addresses are valid for binding or connecting
5409 * based on their @optname.
5410 */
selinux_sctp_bind_connect(struct sock * sk,int optname,struct sockaddr * address,int addrlen)5411 static int selinux_sctp_bind_connect(struct sock *sk, int optname,
5412 struct sockaddr *address,
5413 int addrlen)
5414 {
5415 int len, err = 0, walk_size = 0;
5416 void *addr_buf;
5417 struct sockaddr *addr;
5418 struct socket *sock;
5419
5420 if (!selinux_policycap_extsockclass())
5421 return 0;
5422
5423 /* Process one or more addresses that may be IPv4 or IPv6 */
5424 sock = sk->sk_socket;
5425 addr_buf = address;
5426
5427 while (walk_size < addrlen) {
5428 if (walk_size + sizeof(sa_family_t) > addrlen)
5429 return -EINVAL;
5430
5431 addr = addr_buf;
5432 switch (addr->sa_family) {
5433 case AF_UNSPEC:
5434 case AF_INET:
5435 len = sizeof(struct sockaddr_in);
5436 break;
5437 case AF_INET6:
5438 len = sizeof(struct sockaddr_in6);
5439 break;
5440 default:
5441 return -EINVAL;
5442 }
5443
5444 if (walk_size + len > addrlen)
5445 return -EINVAL;
5446
5447 err = -EINVAL;
5448 switch (optname) {
5449 /* Bind checks */
5450 case SCTP_PRIMARY_ADDR:
5451 case SCTP_SET_PEER_PRIMARY_ADDR:
5452 case SCTP_SOCKOPT_BINDX_ADD:
5453 err = selinux_socket_bind(sock, addr, len);
5454 break;
5455 /* Connect checks */
5456 case SCTP_SOCKOPT_CONNECTX:
5457 case SCTP_PARAM_SET_PRIMARY:
5458 case SCTP_PARAM_ADD_IP:
5459 case SCTP_SENDMSG_CONNECT:
5460 err = selinux_socket_connect_helper(sock, addr, len);
5461 if (err)
5462 return err;
5463
5464 /* As selinux_sctp_bind_connect() is called by the
5465 * SCTP protocol layer, the socket is already locked,
5466 * therefore selinux_netlbl_socket_connect_locked()
5467 * is called here. The situations handled are:
5468 * sctp_connectx(3), sctp_sendmsg(3), sendmsg(2),
5469 * whenever a new IP address is added or when a new
5470 * primary address is selected.
5471 * Note that an SCTP connect(2) call happens before
5472 * the SCTP protocol layer and is handled via
5473 * selinux_socket_connect().
5474 */
5475 err = selinux_netlbl_socket_connect_locked(sk, addr);
5476 break;
5477 }
5478
5479 if (err)
5480 return err;
5481
5482 addr_buf += len;
5483 walk_size += len;
5484 }
5485
5486 return 0;
5487 }
5488
5489 /* Called whenever a new socket is created by accept(2) or sctp_peeloff(3). */
selinux_sctp_sk_clone(struct sctp_association * asoc,struct sock * sk,struct sock * newsk)5490 static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk,
5491 struct sock *newsk)
5492 {
5493 struct sk_security_struct *sksec = selinux_sock(sk);
5494 struct sk_security_struct *newsksec = selinux_sock(newsk);
5495
5496 /* If policy does not support SECCLASS_SCTP_SOCKET then call
5497 * the non-sctp clone version.
5498 */
5499 if (!selinux_policycap_extsockclass())
5500 return selinux_sk_clone_security(sk, newsk);
5501
5502 newsksec->sid = asoc->secid;
5503 newsksec->peer_sid = asoc->peer_secid;
5504 newsksec->sclass = sksec->sclass;
5505 selinux_netlbl_sctp_sk_clone(sk, newsk);
5506 }
5507
selinux_mptcp_add_subflow(struct sock * sk,struct sock * ssk)5508 static int selinux_mptcp_add_subflow(struct sock *sk, struct sock *ssk)
5509 {
5510 struct sk_security_struct *ssksec = selinux_sock(ssk);
5511 struct sk_security_struct *sksec = selinux_sock(sk);
5512
5513 ssksec->sclass = sksec->sclass;
5514 ssksec->sid = sksec->sid;
5515
5516 /* replace the existing subflow label deleting the existing one
5517 * and re-recreating a new label using the updated context
5518 */
5519 selinux_netlbl_sk_security_free(ssksec);
5520 return selinux_netlbl_socket_post_create(ssk, ssk->sk_family);
5521 }
5522
selinux_inet_conn_request(const struct sock * sk,struct sk_buff * skb,struct request_sock * req)5523 static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
5524 struct request_sock *req)
5525 {
5526 struct sk_security_struct *sksec = selinux_sock(sk);
5527 int err;
5528 u16 family = req->rsk_ops->family;
5529 u32 connsid;
5530 u32 peersid;
5531
5532 err = selinux_skb_peerlbl_sid(skb, family, &peersid);
5533 if (err)
5534 return err;
5535 err = selinux_conn_sid(sksec->sid, peersid, &connsid);
5536 if (err)
5537 return err;
5538 req->secid = connsid;
5539 req->peer_secid = peersid;
5540
5541 return selinux_netlbl_inet_conn_request(req, family);
5542 }
5543
selinux_inet_csk_clone(struct sock * newsk,const struct request_sock * req)5544 static void selinux_inet_csk_clone(struct sock *newsk,
5545 const struct request_sock *req)
5546 {
5547 struct sk_security_struct *newsksec = selinux_sock(newsk);
5548
5549 newsksec->sid = req->secid;
5550 newsksec->peer_sid = req->peer_secid;
5551 /* NOTE: Ideally, we should also get the isec->sid for the
5552 new socket in sync, but we don't have the isec available yet.
5553 So we will wait until sock_graft to do it, by which
5554 time it will have been created and available. */
5555
5556 /* We don't need to take any sort of lock here as we are the only
5557 * thread with access to newsksec */
5558 selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
5559 }
5560
selinux_inet_conn_established(struct sock * sk,struct sk_buff * skb)5561 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
5562 {
5563 u16 family = sk->sk_family;
5564 struct sk_security_struct *sksec = selinux_sock(sk);
5565
5566 /* handle mapped IPv4 packets arriving via IPv6 sockets */
5567 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5568 family = PF_INET;
5569
5570 selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
5571 }
5572
selinux_secmark_relabel_packet(u32 sid)5573 static int selinux_secmark_relabel_packet(u32 sid)
5574 {
5575 return avc_has_perm(current_sid(), sid, SECCLASS_PACKET, PACKET__RELABELTO,
5576 NULL);
5577 }
5578
selinux_secmark_refcount_inc(void)5579 static void selinux_secmark_refcount_inc(void)
5580 {
5581 atomic_inc(&selinux_secmark_refcount);
5582 }
5583
selinux_secmark_refcount_dec(void)5584 static void selinux_secmark_refcount_dec(void)
5585 {
5586 atomic_dec(&selinux_secmark_refcount);
5587 }
5588
selinux_req_classify_flow(const struct request_sock * req,struct flowi_common * flic)5589 static void selinux_req_classify_flow(const struct request_sock *req,
5590 struct flowi_common *flic)
5591 {
5592 flic->flowic_secid = req->secid;
5593 }
5594
selinux_tun_dev_alloc_security(void * security)5595 static int selinux_tun_dev_alloc_security(void *security)
5596 {
5597 struct tun_security_struct *tunsec = selinux_tun_dev(security);
5598
5599 tunsec->sid = current_sid();
5600 return 0;
5601 }
5602
selinux_tun_dev_create(void)5603 static int selinux_tun_dev_create(void)
5604 {
5605 u32 sid = current_sid();
5606
5607 /* we aren't taking into account the "sockcreate" SID since the socket
5608 * that is being created here is not a socket in the traditional sense,
5609 * instead it is a private sock, accessible only to the kernel, and
5610 * representing a wide range of network traffic spanning multiple
5611 * connections unlike traditional sockets - check the TUN driver to
5612 * get a better understanding of why this socket is special */
5613
5614 return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
5615 NULL);
5616 }
5617
selinux_tun_dev_attach_queue(void * security)5618 static int selinux_tun_dev_attach_queue(void *security)
5619 {
5620 struct tun_security_struct *tunsec = selinux_tun_dev(security);
5621
5622 return avc_has_perm(current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET,
5623 TUN_SOCKET__ATTACH_QUEUE, NULL);
5624 }
5625
selinux_tun_dev_attach(struct sock * sk,void * security)5626 static int selinux_tun_dev_attach(struct sock *sk, void *security)
5627 {
5628 struct tun_security_struct *tunsec = selinux_tun_dev(security);
5629 struct sk_security_struct *sksec = selinux_sock(sk);
5630
5631 /* we don't currently perform any NetLabel based labeling here and it
5632 * isn't clear that we would want to do so anyway; while we could apply
5633 * labeling without the support of the TUN user the resulting labeled
5634 * traffic from the other end of the connection would almost certainly
5635 * cause confusion to the TUN user that had no idea network labeling
5636 * protocols were being used */
5637
5638 sksec->sid = tunsec->sid;
5639 sksec->sclass = SECCLASS_TUN_SOCKET;
5640
5641 return 0;
5642 }
5643
selinux_tun_dev_open(void * security)5644 static int selinux_tun_dev_open(void *security)
5645 {
5646 struct tun_security_struct *tunsec = selinux_tun_dev(security);
5647 u32 sid = current_sid();
5648 int err;
5649
5650 err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET,
5651 TUN_SOCKET__RELABELFROM, NULL);
5652 if (err)
5653 return err;
5654 err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
5655 TUN_SOCKET__RELABELTO, NULL);
5656 if (err)
5657 return err;
5658 tunsec->sid = sid;
5659
5660 return 0;
5661 }
5662
5663 #ifdef CONFIG_NETFILTER
5664
selinux_ip_forward(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5665 static unsigned int selinux_ip_forward(void *priv, struct sk_buff *skb,
5666 const struct nf_hook_state *state)
5667 {
5668 int ifindex;
5669 u16 family;
5670 char *addrp;
5671 u32 peer_sid;
5672 struct common_audit_data ad;
5673 struct lsm_network_audit net;
5674 int secmark_active, peerlbl_active;
5675
5676 if (!selinux_policycap_netpeer())
5677 return NF_ACCEPT;
5678
5679 secmark_active = selinux_secmark_enabled();
5680 peerlbl_active = selinux_peerlbl_enabled();
5681 if (!secmark_active && !peerlbl_active)
5682 return NF_ACCEPT;
5683
5684 family = state->pf;
5685 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
5686 return NF_DROP;
5687
5688 ifindex = state->in->ifindex;
5689 ad_net_init_from_iif(&ad, &net, ifindex, family);
5690 if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
5691 return NF_DROP;
5692
5693 if (peerlbl_active) {
5694 int err;
5695
5696 err = selinux_inet_sys_rcv_skb(state->net, ifindex,
5697 addrp, family, peer_sid, &ad);
5698 if (err) {
5699 selinux_netlbl_err(skb, family, err, 1);
5700 return NF_DROP;
5701 }
5702 }
5703
5704 if (secmark_active)
5705 if (avc_has_perm(peer_sid, skb->secmark,
5706 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
5707 return NF_DROP;
5708
5709 if (netlbl_enabled())
5710 /* we do this in the FORWARD path and not the POST_ROUTING
5711 * path because we want to make sure we apply the necessary
5712 * labeling before IPsec is applied so we can leverage AH
5713 * protection */
5714 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
5715 return NF_DROP;
5716
5717 return NF_ACCEPT;
5718 }
5719
selinux_ip_output(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5720 static unsigned int selinux_ip_output(void *priv, struct sk_buff *skb,
5721 const struct nf_hook_state *state)
5722 {
5723 struct sock *sk;
5724 u32 sid;
5725
5726 if (!netlbl_enabled())
5727 return NF_ACCEPT;
5728
5729 /* we do this in the LOCAL_OUT path and not the POST_ROUTING path
5730 * because we want to make sure we apply the necessary labeling
5731 * before IPsec is applied so we can leverage AH protection */
5732 sk = skb->sk;
5733 if (sk) {
5734 struct sk_security_struct *sksec;
5735
5736 if (sk_listener(sk))
5737 /* if the socket is the listening state then this
5738 * packet is a SYN-ACK packet which means it needs to
5739 * be labeled based on the connection/request_sock and
5740 * not the parent socket. unfortunately, we can't
5741 * lookup the request_sock yet as it isn't queued on
5742 * the parent socket until after the SYN-ACK is sent.
5743 * the "solution" is to simply pass the packet as-is
5744 * as any IP option based labeling should be copied
5745 * from the initial connection request (in the IP
5746 * layer). it is far from ideal, but until we get a
5747 * security label in the packet itself this is the
5748 * best we can do. */
5749 return NF_ACCEPT;
5750
5751 /* standard practice, label using the parent socket */
5752 sksec = selinux_sock(sk);
5753 sid = sksec->sid;
5754 } else
5755 sid = SECINITSID_KERNEL;
5756 if (selinux_netlbl_skbuff_setsid(skb, state->pf, sid) != 0)
5757 return NF_DROP;
5758
5759 return NF_ACCEPT;
5760 }
5761
5762
selinux_ip_postroute_compat(struct sk_buff * skb,const struct nf_hook_state * state)5763 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
5764 const struct nf_hook_state *state)
5765 {
5766 struct sock *sk;
5767 struct sk_security_struct *sksec;
5768 struct common_audit_data ad;
5769 struct lsm_network_audit net;
5770 u8 proto = 0;
5771
5772 sk = skb_to_full_sk(skb);
5773 if (sk == NULL)
5774 return NF_ACCEPT;
5775 sksec = selinux_sock(sk);
5776
5777 ad_net_init_from_iif(&ad, &net, state->out->ifindex, state->pf);
5778 if (selinux_parse_skb(skb, &ad, NULL, 0, &proto))
5779 return NF_DROP;
5780
5781 if (selinux_secmark_enabled())
5782 if (avc_has_perm(sksec->sid, skb->secmark,
5783 SECCLASS_PACKET, PACKET__SEND, &ad))
5784 return NF_DROP_ERR(-ECONNREFUSED);
5785
5786 if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
5787 return NF_DROP_ERR(-ECONNREFUSED);
5788
5789 return NF_ACCEPT;
5790 }
5791
selinux_ip_postroute(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5792 static unsigned int selinux_ip_postroute(void *priv,
5793 struct sk_buff *skb,
5794 const struct nf_hook_state *state)
5795 {
5796 u16 family;
5797 u32 secmark_perm;
5798 u32 peer_sid;
5799 int ifindex;
5800 struct sock *sk;
5801 struct common_audit_data ad;
5802 struct lsm_network_audit net;
5803 char *addrp;
5804 int secmark_active, peerlbl_active;
5805
5806 /* If any sort of compatibility mode is enabled then handoff processing
5807 * to the selinux_ip_postroute_compat() function to deal with the
5808 * special handling. We do this in an attempt to keep this function
5809 * as fast and as clean as possible. */
5810 if (!selinux_policycap_netpeer())
5811 return selinux_ip_postroute_compat(skb, state);
5812
5813 secmark_active = selinux_secmark_enabled();
5814 peerlbl_active = selinux_peerlbl_enabled();
5815 if (!secmark_active && !peerlbl_active)
5816 return NF_ACCEPT;
5817
5818 sk = skb_to_full_sk(skb);
5819
5820 #ifdef CONFIG_XFRM
5821 /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
5822 * packet transformation so allow the packet to pass without any checks
5823 * since we'll have another chance to perform access control checks
5824 * when the packet is on it's final way out.
5825 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
5826 * is NULL, in this case go ahead and apply access control.
5827 * NOTE: if this is a local socket (skb->sk != NULL) that is in the
5828 * TCP listening state we cannot wait until the XFRM processing
5829 * is done as we will miss out on the SA label if we do;
5830 * unfortunately, this means more work, but it is only once per
5831 * connection. */
5832 if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&
5833 !(sk && sk_listener(sk)))
5834 return NF_ACCEPT;
5835 #endif
5836
5837 family = state->pf;
5838 if (sk == NULL) {
5839 /* Without an associated socket the packet is either coming
5840 * from the kernel or it is being forwarded; check the packet
5841 * to determine which and if the packet is being forwarded
5842 * query the packet directly to determine the security label. */
5843 if (skb->skb_iif) {
5844 secmark_perm = PACKET__FORWARD_OUT;
5845 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
5846 return NF_DROP;
5847 } else {
5848 secmark_perm = PACKET__SEND;
5849 peer_sid = SECINITSID_KERNEL;
5850 }
5851 } else if (sk_listener(sk)) {
5852 /* Locally generated packet but the associated socket is in the
5853 * listening state which means this is a SYN-ACK packet. In
5854 * this particular case the correct security label is assigned
5855 * to the connection/request_sock but unfortunately we can't
5856 * query the request_sock as it isn't queued on the parent
5857 * socket until after the SYN-ACK packet is sent; the only
5858 * viable choice is to regenerate the label like we do in
5859 * selinux_inet_conn_request(). See also selinux_ip_output()
5860 * for similar problems. */
5861 u32 skb_sid;
5862 struct sk_security_struct *sksec;
5863
5864 sksec = selinux_sock(sk);
5865 if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
5866 return NF_DROP;
5867 /* At this point, if the returned skb peerlbl is SECSID_NULL
5868 * and the packet has been through at least one XFRM
5869 * transformation then we must be dealing with the "final"
5870 * form of labeled IPsec packet; since we've already applied
5871 * all of our access controls on this packet we can safely
5872 * pass the packet. */
5873 if (skb_sid == SECSID_NULL) {
5874 switch (family) {
5875 case PF_INET:
5876 if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
5877 return NF_ACCEPT;
5878 break;
5879 case PF_INET6:
5880 if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
5881 return NF_ACCEPT;
5882 break;
5883 default:
5884 return NF_DROP_ERR(-ECONNREFUSED);
5885 }
5886 }
5887 if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
5888 return NF_DROP;
5889 secmark_perm = PACKET__SEND;
5890 } else {
5891 /* Locally generated packet, fetch the security label from the
5892 * associated socket. */
5893 struct sk_security_struct *sksec = selinux_sock(sk);
5894 peer_sid = sksec->sid;
5895 secmark_perm = PACKET__SEND;
5896 }
5897
5898 ifindex = state->out->ifindex;
5899 ad_net_init_from_iif(&ad, &net, ifindex, family);
5900 if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
5901 return NF_DROP;
5902
5903 if (secmark_active)
5904 if (avc_has_perm(peer_sid, skb->secmark,
5905 SECCLASS_PACKET, secmark_perm, &ad))
5906 return NF_DROP_ERR(-ECONNREFUSED);
5907
5908 if (peerlbl_active) {
5909 u32 if_sid;
5910 u32 node_sid;
5911
5912 if (sel_netif_sid(state->net, ifindex, &if_sid))
5913 return NF_DROP;
5914 if (avc_has_perm(peer_sid, if_sid,
5915 SECCLASS_NETIF, NETIF__EGRESS, &ad))
5916 return NF_DROP_ERR(-ECONNREFUSED);
5917
5918 if (sel_netnode_sid(addrp, family, &node_sid))
5919 return NF_DROP;
5920 if (avc_has_perm(peer_sid, node_sid,
5921 SECCLASS_NODE, NODE__SENDTO, &ad))
5922 return NF_DROP_ERR(-ECONNREFUSED);
5923 }
5924
5925 return NF_ACCEPT;
5926 }
5927 #endif /* CONFIG_NETFILTER */
5928
selinux_netlink_send(struct sock * sk,struct sk_buff * skb)5929 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
5930 {
5931 int rc = 0;
5932 unsigned int msg_len;
5933 unsigned int data_len = skb->len;
5934 unsigned char *data = skb->data;
5935 struct nlmsghdr *nlh;
5936 struct sk_security_struct *sksec = selinux_sock(sk);
5937 u16 sclass = sksec->sclass;
5938 u32 perm;
5939
5940 while (data_len >= nlmsg_total_size(0)) {
5941 nlh = (struct nlmsghdr *)data;
5942
5943 /* NOTE: the nlmsg_len field isn't reliably set by some netlink
5944 * users which means we can't reject skb's with bogus
5945 * length fields; our solution is to follow what
5946 * netlink_rcv_skb() does and simply skip processing at
5947 * messages with length fields that are clearly junk
5948 */
5949 if (nlh->nlmsg_len < NLMSG_HDRLEN || nlh->nlmsg_len > data_len)
5950 return 0;
5951
5952 rc = selinux_nlmsg_lookup(sclass, nlh->nlmsg_type, &perm);
5953 if (rc == 0) {
5954 rc = sock_has_perm(sk, perm);
5955 if (rc)
5956 return rc;
5957 } else if (rc == -EINVAL) {
5958 /* -EINVAL is a missing msg/perm mapping */
5959 pr_warn_ratelimited("SELinux: unrecognized netlink"
5960 " message: protocol=%hu nlmsg_type=%hu sclass=%s"
5961 " pid=%d comm=%s\n",
5962 sk->sk_protocol, nlh->nlmsg_type,
5963 secclass_map[sclass - 1].name,
5964 task_pid_nr(current), current->comm);
5965 if (enforcing_enabled() &&
5966 !security_get_allow_unknown())
5967 return rc;
5968 rc = 0;
5969 } else if (rc == -ENOENT) {
5970 /* -ENOENT is a missing socket/class mapping, ignore */
5971 rc = 0;
5972 } else {
5973 return rc;
5974 }
5975
5976 /* move to the next message after applying netlink padding */
5977 msg_len = NLMSG_ALIGN(nlh->nlmsg_len);
5978 if (msg_len >= data_len)
5979 return 0;
5980 data_len -= msg_len;
5981 data += msg_len;
5982 }
5983
5984 return rc;
5985 }
5986
ipc_init_security(struct ipc_security_struct * isec,u16 sclass)5987 static void ipc_init_security(struct ipc_security_struct *isec, u16 sclass)
5988 {
5989 isec->sclass = sclass;
5990 isec->sid = current_sid();
5991 }
5992
ipc_has_perm(struct kern_ipc_perm * ipc_perms,u32 perms)5993 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
5994 u32 perms)
5995 {
5996 struct ipc_security_struct *isec;
5997 struct common_audit_data ad;
5998 u32 sid = current_sid();
5999
6000 isec = selinux_ipc(ipc_perms);
6001
6002 ad.type = LSM_AUDIT_DATA_IPC;
6003 ad.u.ipc_id = ipc_perms->key;
6004
6005 return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
6006 }
6007
selinux_msg_msg_alloc_security(struct msg_msg * msg)6008 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
6009 {
6010 struct msg_security_struct *msec;
6011
6012 msec = selinux_msg_msg(msg);
6013 msec->sid = SECINITSID_UNLABELED;
6014
6015 return 0;
6016 }
6017
6018 /* message queue security operations */
selinux_msg_queue_alloc_security(struct kern_ipc_perm * msq)6019 static int selinux_msg_queue_alloc_security(struct kern_ipc_perm *msq)
6020 {
6021 struct ipc_security_struct *isec;
6022 struct common_audit_data ad;
6023 u32 sid = current_sid();
6024
6025 isec = selinux_ipc(msq);
6026 ipc_init_security(isec, SECCLASS_MSGQ);
6027
6028 ad.type = LSM_AUDIT_DATA_IPC;
6029 ad.u.ipc_id = msq->key;
6030
6031 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
6032 MSGQ__CREATE, &ad);
6033 }
6034
selinux_msg_queue_associate(struct kern_ipc_perm * msq,int msqflg)6035 static int selinux_msg_queue_associate(struct kern_ipc_perm *msq, int msqflg)
6036 {
6037 struct ipc_security_struct *isec;
6038 struct common_audit_data ad;
6039 u32 sid = current_sid();
6040
6041 isec = selinux_ipc(msq);
6042
6043 ad.type = LSM_AUDIT_DATA_IPC;
6044 ad.u.ipc_id = msq->key;
6045
6046 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
6047 MSGQ__ASSOCIATE, &ad);
6048 }
6049
selinux_msg_queue_msgctl(struct kern_ipc_perm * msq,int cmd)6050 static int selinux_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd)
6051 {
6052 u32 perms;
6053
6054 switch (cmd) {
6055 case IPC_INFO:
6056 case MSG_INFO:
6057 /* No specific object, just general system-wide information. */
6058 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
6059 SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6060 case IPC_STAT:
6061 case MSG_STAT:
6062 case MSG_STAT_ANY:
6063 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
6064 break;
6065 case IPC_SET:
6066 perms = MSGQ__SETATTR;
6067 break;
6068 case IPC_RMID:
6069 perms = MSGQ__DESTROY;
6070 break;
6071 default:
6072 return 0;
6073 }
6074
6075 return ipc_has_perm(msq, perms);
6076 }
6077
selinux_msg_queue_msgsnd(struct kern_ipc_perm * msq,struct msg_msg * msg,int msqflg)6078 static int selinux_msg_queue_msgsnd(struct kern_ipc_perm *msq, struct msg_msg *msg, int msqflg)
6079 {
6080 struct ipc_security_struct *isec;
6081 struct msg_security_struct *msec;
6082 struct common_audit_data ad;
6083 u32 sid = current_sid();
6084 int rc;
6085
6086 isec = selinux_ipc(msq);
6087 msec = selinux_msg_msg(msg);
6088
6089 /*
6090 * First time through, need to assign label to the message
6091 */
6092 if (msec->sid == SECINITSID_UNLABELED) {
6093 /*
6094 * Compute new sid based on current process and
6095 * message queue this message will be stored in
6096 */
6097 rc = security_transition_sid(sid, isec->sid,
6098 SECCLASS_MSG, NULL, &msec->sid);
6099 if (rc)
6100 return rc;
6101 }
6102
6103 ad.type = LSM_AUDIT_DATA_IPC;
6104 ad.u.ipc_id = msq->key;
6105
6106 /* Can this process write to the queue? */
6107 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
6108 MSGQ__WRITE, &ad);
6109 if (!rc)
6110 /* Can this process send the message */
6111 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
6112 MSG__SEND, &ad);
6113 if (!rc)
6114 /* Can the message be put in the queue? */
6115 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
6116 MSGQ__ENQUEUE, &ad);
6117
6118 return rc;
6119 }
6120
selinux_msg_queue_msgrcv(struct kern_ipc_perm * msq,struct msg_msg * msg,struct task_struct * target,long type,int mode)6121 static int selinux_msg_queue_msgrcv(struct kern_ipc_perm *msq, struct msg_msg *msg,
6122 struct task_struct *target,
6123 long type, int mode)
6124 {
6125 struct ipc_security_struct *isec;
6126 struct msg_security_struct *msec;
6127 struct common_audit_data ad;
6128 u32 sid = task_sid_obj(target);
6129 int rc;
6130
6131 isec = selinux_ipc(msq);
6132 msec = selinux_msg_msg(msg);
6133
6134 ad.type = LSM_AUDIT_DATA_IPC;
6135 ad.u.ipc_id = msq->key;
6136
6137 rc = avc_has_perm(sid, isec->sid,
6138 SECCLASS_MSGQ, MSGQ__READ, &ad);
6139 if (!rc)
6140 rc = avc_has_perm(sid, msec->sid,
6141 SECCLASS_MSG, MSG__RECEIVE, &ad);
6142 return rc;
6143 }
6144
6145 /* Shared Memory security operations */
selinux_shm_alloc_security(struct kern_ipc_perm * shp)6146 static int selinux_shm_alloc_security(struct kern_ipc_perm *shp)
6147 {
6148 struct ipc_security_struct *isec;
6149 struct common_audit_data ad;
6150 u32 sid = current_sid();
6151
6152 isec = selinux_ipc(shp);
6153 ipc_init_security(isec, SECCLASS_SHM);
6154
6155 ad.type = LSM_AUDIT_DATA_IPC;
6156 ad.u.ipc_id = shp->key;
6157
6158 return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
6159 SHM__CREATE, &ad);
6160 }
6161
selinux_shm_associate(struct kern_ipc_perm * shp,int shmflg)6162 static int selinux_shm_associate(struct kern_ipc_perm *shp, int shmflg)
6163 {
6164 struct ipc_security_struct *isec;
6165 struct common_audit_data ad;
6166 u32 sid = current_sid();
6167
6168 isec = selinux_ipc(shp);
6169
6170 ad.type = LSM_AUDIT_DATA_IPC;
6171 ad.u.ipc_id = shp->key;
6172
6173 return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
6174 SHM__ASSOCIATE, &ad);
6175 }
6176
6177 /* Note, at this point, shp is locked down */
selinux_shm_shmctl(struct kern_ipc_perm * shp,int cmd)6178 static int selinux_shm_shmctl(struct kern_ipc_perm *shp, int cmd)
6179 {
6180 u32 perms;
6181
6182 switch (cmd) {
6183 case IPC_INFO:
6184 case SHM_INFO:
6185 /* No specific object, just general system-wide information. */
6186 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
6187 SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6188 case IPC_STAT:
6189 case SHM_STAT:
6190 case SHM_STAT_ANY:
6191 perms = SHM__GETATTR | SHM__ASSOCIATE;
6192 break;
6193 case IPC_SET:
6194 perms = SHM__SETATTR;
6195 break;
6196 case SHM_LOCK:
6197 case SHM_UNLOCK:
6198 perms = SHM__LOCK;
6199 break;
6200 case IPC_RMID:
6201 perms = SHM__DESTROY;
6202 break;
6203 default:
6204 return 0;
6205 }
6206
6207 return ipc_has_perm(shp, perms);
6208 }
6209
selinux_shm_shmat(struct kern_ipc_perm * shp,char __user * shmaddr,int shmflg)6210 static int selinux_shm_shmat(struct kern_ipc_perm *shp,
6211 char __user *shmaddr, int shmflg)
6212 {
6213 u32 perms;
6214
6215 if (shmflg & SHM_RDONLY)
6216 perms = SHM__READ;
6217 else
6218 perms = SHM__READ | SHM__WRITE;
6219
6220 return ipc_has_perm(shp, perms);
6221 }
6222
6223 /* Semaphore security operations */
selinux_sem_alloc_security(struct kern_ipc_perm * sma)6224 static int selinux_sem_alloc_security(struct kern_ipc_perm *sma)
6225 {
6226 struct ipc_security_struct *isec;
6227 struct common_audit_data ad;
6228 u32 sid = current_sid();
6229
6230 isec = selinux_ipc(sma);
6231 ipc_init_security(isec, SECCLASS_SEM);
6232
6233 ad.type = LSM_AUDIT_DATA_IPC;
6234 ad.u.ipc_id = sma->key;
6235
6236 return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
6237 SEM__CREATE, &ad);
6238 }
6239
selinux_sem_associate(struct kern_ipc_perm * sma,int semflg)6240 static int selinux_sem_associate(struct kern_ipc_perm *sma, int semflg)
6241 {
6242 struct ipc_security_struct *isec;
6243 struct common_audit_data ad;
6244 u32 sid = current_sid();
6245
6246 isec = selinux_ipc(sma);
6247
6248 ad.type = LSM_AUDIT_DATA_IPC;
6249 ad.u.ipc_id = sma->key;
6250
6251 return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
6252 SEM__ASSOCIATE, &ad);
6253 }
6254
6255 /* Note, at this point, sma is locked down */
selinux_sem_semctl(struct kern_ipc_perm * sma,int cmd)6256 static int selinux_sem_semctl(struct kern_ipc_perm *sma, int cmd)
6257 {
6258 int err;
6259 u32 perms;
6260
6261 switch (cmd) {
6262 case IPC_INFO:
6263 case SEM_INFO:
6264 /* No specific object, just general system-wide information. */
6265 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
6266 SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6267 case GETPID:
6268 case GETNCNT:
6269 case GETZCNT:
6270 perms = SEM__GETATTR;
6271 break;
6272 case GETVAL:
6273 case GETALL:
6274 perms = SEM__READ;
6275 break;
6276 case SETVAL:
6277 case SETALL:
6278 perms = SEM__WRITE;
6279 break;
6280 case IPC_RMID:
6281 perms = SEM__DESTROY;
6282 break;
6283 case IPC_SET:
6284 perms = SEM__SETATTR;
6285 break;
6286 case IPC_STAT:
6287 case SEM_STAT:
6288 case SEM_STAT_ANY:
6289 perms = SEM__GETATTR | SEM__ASSOCIATE;
6290 break;
6291 default:
6292 return 0;
6293 }
6294
6295 err = ipc_has_perm(sma, perms);
6296 return err;
6297 }
6298
selinux_sem_semop(struct kern_ipc_perm * sma,struct sembuf * sops,unsigned nsops,int alter)6299 static int selinux_sem_semop(struct kern_ipc_perm *sma,
6300 struct sembuf *sops, unsigned nsops, int alter)
6301 {
6302 u32 perms;
6303
6304 if (alter)
6305 perms = SEM__READ | SEM__WRITE;
6306 else
6307 perms = SEM__READ;
6308
6309 return ipc_has_perm(sma, perms);
6310 }
6311
selinux_ipc_permission(struct kern_ipc_perm * ipcp,short flag)6312 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
6313 {
6314 u32 av = 0;
6315
6316 av = 0;
6317 if (flag & S_IRUGO)
6318 av |= IPC__UNIX_READ;
6319 if (flag & S_IWUGO)
6320 av |= IPC__UNIX_WRITE;
6321
6322 if (av == 0)
6323 return 0;
6324
6325 return ipc_has_perm(ipcp, av);
6326 }
6327
selinux_ipc_getsecid(struct kern_ipc_perm * ipcp,u32 * secid)6328 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
6329 {
6330 struct ipc_security_struct *isec = selinux_ipc(ipcp);
6331 *secid = isec->sid;
6332 }
6333
selinux_d_instantiate(struct dentry * dentry,struct inode * inode)6334 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
6335 {
6336 if (inode)
6337 inode_doinit_with_dentry(inode, dentry);
6338 }
6339
selinux_lsm_getattr(unsigned int attr,struct task_struct * p,char ** value)6340 static int selinux_lsm_getattr(unsigned int attr, struct task_struct *p,
6341 char **value)
6342 {
6343 const struct task_security_struct *tsec;
6344 int error;
6345 u32 sid;
6346 u32 len;
6347
6348 rcu_read_lock();
6349 tsec = selinux_cred(__task_cred(p));
6350 if (p != current) {
6351 error = avc_has_perm(current_sid(), tsec->sid,
6352 SECCLASS_PROCESS, PROCESS__GETATTR, NULL);
6353 if (error)
6354 goto err_unlock;
6355 }
6356 switch (attr) {
6357 case LSM_ATTR_CURRENT:
6358 sid = tsec->sid;
6359 break;
6360 case LSM_ATTR_PREV:
6361 sid = tsec->osid;
6362 break;
6363 case LSM_ATTR_EXEC:
6364 sid = tsec->exec_sid;
6365 break;
6366 case LSM_ATTR_FSCREATE:
6367 sid = tsec->create_sid;
6368 break;
6369 case LSM_ATTR_KEYCREATE:
6370 sid = tsec->keycreate_sid;
6371 break;
6372 case LSM_ATTR_SOCKCREATE:
6373 sid = tsec->sockcreate_sid;
6374 break;
6375 default:
6376 error = -EOPNOTSUPP;
6377 goto err_unlock;
6378 }
6379 rcu_read_unlock();
6380
6381 if (sid == SECSID_NULL) {
6382 *value = NULL;
6383 return 0;
6384 }
6385
6386 error = security_sid_to_context(sid, value, &len);
6387 if (error)
6388 return error;
6389 return len;
6390
6391 err_unlock:
6392 rcu_read_unlock();
6393 return error;
6394 }
6395
selinux_lsm_setattr(u64 attr,void * value,size_t size)6396 static int selinux_lsm_setattr(u64 attr, void *value, size_t size)
6397 {
6398 struct task_security_struct *tsec;
6399 struct cred *new;
6400 u32 mysid = current_sid(), sid = 0, ptsid;
6401 int error;
6402 char *str = value;
6403
6404 /*
6405 * Basic control over ability to set these attributes at all.
6406 */
6407 switch (attr) {
6408 case LSM_ATTR_EXEC:
6409 error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6410 PROCESS__SETEXEC, NULL);
6411 break;
6412 case LSM_ATTR_FSCREATE:
6413 error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6414 PROCESS__SETFSCREATE, NULL);
6415 break;
6416 case LSM_ATTR_KEYCREATE:
6417 error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6418 PROCESS__SETKEYCREATE, NULL);
6419 break;
6420 case LSM_ATTR_SOCKCREATE:
6421 error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6422 PROCESS__SETSOCKCREATE, NULL);
6423 break;
6424 case LSM_ATTR_CURRENT:
6425 error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6426 PROCESS__SETCURRENT, NULL);
6427 break;
6428 default:
6429 error = -EOPNOTSUPP;
6430 break;
6431 }
6432 if (error)
6433 return error;
6434
6435 /* Obtain a SID for the context, if one was specified. */
6436 if (size && str[0] && str[0] != '\n') {
6437 if (str[size-1] == '\n') {
6438 str[size-1] = 0;
6439 size--;
6440 }
6441 error = security_context_to_sid(value, size,
6442 &sid, GFP_KERNEL);
6443 if (error == -EINVAL && attr == LSM_ATTR_FSCREATE) {
6444 if (!has_cap_mac_admin(true)) {
6445 struct audit_buffer *ab;
6446 size_t audit_size;
6447
6448 /* We strip a nul only if it is at the end,
6449 * otherwise the context contains a nul and
6450 * we should audit that */
6451 if (str[size - 1] == '\0')
6452 audit_size = size - 1;
6453 else
6454 audit_size = size;
6455 ab = audit_log_start(audit_context(),
6456 GFP_ATOMIC,
6457 AUDIT_SELINUX_ERR);
6458 if (!ab)
6459 return error;
6460 audit_log_format(ab, "op=fscreate invalid_context=");
6461 audit_log_n_untrustedstring(ab, value,
6462 audit_size);
6463 audit_log_end(ab);
6464
6465 return error;
6466 }
6467 error = security_context_to_sid_force(value, size,
6468 &sid);
6469 }
6470 if (error)
6471 return error;
6472 }
6473
6474 new = prepare_creds();
6475 if (!new)
6476 return -ENOMEM;
6477
6478 /* Permission checking based on the specified context is
6479 performed during the actual operation (execve,
6480 open/mkdir/...), when we know the full context of the
6481 operation. See selinux_bprm_creds_for_exec for the execve
6482 checks and may_create for the file creation checks. The
6483 operation will then fail if the context is not permitted. */
6484 tsec = selinux_cred(new);
6485 if (attr == LSM_ATTR_EXEC) {
6486 tsec->exec_sid = sid;
6487 } else if (attr == LSM_ATTR_FSCREATE) {
6488 tsec->create_sid = sid;
6489 } else if (attr == LSM_ATTR_KEYCREATE) {
6490 if (sid) {
6491 error = avc_has_perm(mysid, sid,
6492 SECCLASS_KEY, KEY__CREATE, NULL);
6493 if (error)
6494 goto abort_change;
6495 }
6496 tsec->keycreate_sid = sid;
6497 } else if (attr == LSM_ATTR_SOCKCREATE) {
6498 tsec->sockcreate_sid = sid;
6499 } else if (attr == LSM_ATTR_CURRENT) {
6500 error = -EINVAL;
6501 if (sid == 0)
6502 goto abort_change;
6503
6504 if (!current_is_single_threaded()) {
6505 error = security_bounded_transition(tsec->sid, sid);
6506 if (error)
6507 goto abort_change;
6508 }
6509
6510 /* Check permissions for the transition. */
6511 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
6512 PROCESS__DYNTRANSITION, NULL);
6513 if (error)
6514 goto abort_change;
6515
6516 /* Check for ptracing, and update the task SID if ok.
6517 Otherwise, leave SID unchanged and fail. */
6518 ptsid = ptrace_parent_sid();
6519 if (ptsid != 0) {
6520 error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
6521 PROCESS__PTRACE, NULL);
6522 if (error)
6523 goto abort_change;
6524 }
6525
6526 tsec->sid = sid;
6527 } else {
6528 error = -EINVAL;
6529 goto abort_change;
6530 }
6531
6532 commit_creds(new);
6533 return size;
6534
6535 abort_change:
6536 abort_creds(new);
6537 return error;
6538 }
6539
6540 /**
6541 * selinux_getselfattr - Get SELinux current task attributes
6542 * @attr: the requested attribute
6543 * @ctx: buffer to receive the result
6544 * @size: buffer size (input), buffer size used (output)
6545 * @flags: unused
6546 *
6547 * Fill the passed user space @ctx with the details of the requested
6548 * attribute.
6549 *
6550 * Returns the number of attributes on success, an error code otherwise.
6551 * There will only ever be one attribute.
6552 */
selinux_getselfattr(unsigned int attr,struct lsm_ctx __user * ctx,u32 * size,u32 flags)6553 static int selinux_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx,
6554 u32 *size, u32 flags)
6555 {
6556 int rc;
6557 char *val = NULL;
6558 int val_len;
6559
6560 val_len = selinux_lsm_getattr(attr, current, &val);
6561 if (val_len < 0)
6562 return val_len;
6563 rc = lsm_fill_user_ctx(ctx, size, val, val_len, LSM_ID_SELINUX, 0);
6564 kfree(val);
6565 return (!rc ? 1 : rc);
6566 }
6567
selinux_setselfattr(unsigned int attr,struct lsm_ctx * ctx,u32 size,u32 flags)6568 static int selinux_setselfattr(unsigned int attr, struct lsm_ctx *ctx,
6569 u32 size, u32 flags)
6570 {
6571 int rc;
6572
6573 rc = selinux_lsm_setattr(attr, ctx->ctx, ctx->ctx_len);
6574 if (rc > 0)
6575 return 0;
6576 return rc;
6577 }
6578
selinux_getprocattr(struct task_struct * p,const char * name,char ** value)6579 static int selinux_getprocattr(struct task_struct *p,
6580 const char *name, char **value)
6581 {
6582 unsigned int attr = lsm_name_to_attr(name);
6583 int rc;
6584
6585 if (attr) {
6586 rc = selinux_lsm_getattr(attr, p, value);
6587 if (rc != -EOPNOTSUPP)
6588 return rc;
6589 }
6590
6591 return -EINVAL;
6592 }
6593
selinux_setprocattr(const char * name,void * value,size_t size)6594 static int selinux_setprocattr(const char *name, void *value, size_t size)
6595 {
6596 int attr = lsm_name_to_attr(name);
6597
6598 if (attr)
6599 return selinux_lsm_setattr(attr, value, size);
6600 return -EINVAL;
6601 }
6602
selinux_ismaclabel(const char * name)6603 static int selinux_ismaclabel(const char *name)
6604 {
6605 return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
6606 }
6607
selinux_secid_to_secctx(u32 secid,char ** secdata,u32 * seclen)6608 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
6609 {
6610 return security_sid_to_context(secid,
6611 secdata, seclen);
6612 }
6613
selinux_secctx_to_secid(const char * secdata,u32 seclen,u32 * secid)6614 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
6615 {
6616 return security_context_to_sid(secdata, seclen,
6617 secid, GFP_KERNEL);
6618 }
6619
selinux_release_secctx(char * secdata,u32 seclen)6620 static void selinux_release_secctx(char *secdata, u32 seclen)
6621 {
6622 kfree(secdata);
6623 }
6624
selinux_inode_invalidate_secctx(struct inode * inode)6625 static void selinux_inode_invalidate_secctx(struct inode *inode)
6626 {
6627 struct inode_security_struct *isec = selinux_inode(inode);
6628
6629 spin_lock(&isec->lock);
6630 isec->initialized = LABEL_INVALID;
6631 spin_unlock(&isec->lock);
6632 }
6633
6634 /*
6635 * called with inode->i_mutex locked
6636 */
selinux_inode_notifysecctx(struct inode * inode,void * ctx,u32 ctxlen)6637 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
6638 {
6639 int rc = selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX,
6640 ctx, ctxlen, 0);
6641 /* Do not return error when suppressing label (SBLABEL_MNT not set). */
6642 return rc == -EOPNOTSUPP ? 0 : rc;
6643 }
6644
6645 /*
6646 * called with inode->i_mutex locked
6647 */
selinux_inode_setsecctx(struct dentry * dentry,void * ctx,u32 ctxlen)6648 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
6649 {
6650 return __vfs_setxattr_locked(&nop_mnt_idmap, dentry, XATTR_NAME_SELINUX,
6651 ctx, ctxlen, 0, NULL);
6652 }
6653
selinux_inode_getsecctx(struct inode * inode,void ** ctx,u32 * ctxlen)6654 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
6655 {
6656 int len = 0;
6657 len = selinux_inode_getsecurity(&nop_mnt_idmap, inode,
6658 XATTR_SELINUX_SUFFIX, ctx, true);
6659 if (len < 0)
6660 return len;
6661 *ctxlen = len;
6662 return 0;
6663 }
6664 #ifdef CONFIG_KEYS
6665
selinux_key_alloc(struct key * k,const struct cred * cred,unsigned long flags)6666 static int selinux_key_alloc(struct key *k, const struct cred *cred,
6667 unsigned long flags)
6668 {
6669 const struct task_security_struct *tsec;
6670 struct key_security_struct *ksec = selinux_key(k);
6671
6672 tsec = selinux_cred(cred);
6673 if (tsec->keycreate_sid)
6674 ksec->sid = tsec->keycreate_sid;
6675 else
6676 ksec->sid = tsec->sid;
6677
6678 return 0;
6679 }
6680
selinux_key_permission(key_ref_t key_ref,const struct cred * cred,enum key_need_perm need_perm)6681 static int selinux_key_permission(key_ref_t key_ref,
6682 const struct cred *cred,
6683 enum key_need_perm need_perm)
6684 {
6685 struct key *key;
6686 struct key_security_struct *ksec;
6687 u32 perm, sid;
6688
6689 switch (need_perm) {
6690 case KEY_NEED_VIEW:
6691 perm = KEY__VIEW;
6692 break;
6693 case KEY_NEED_READ:
6694 perm = KEY__READ;
6695 break;
6696 case KEY_NEED_WRITE:
6697 perm = KEY__WRITE;
6698 break;
6699 case KEY_NEED_SEARCH:
6700 perm = KEY__SEARCH;
6701 break;
6702 case KEY_NEED_LINK:
6703 perm = KEY__LINK;
6704 break;
6705 case KEY_NEED_SETATTR:
6706 perm = KEY__SETATTR;
6707 break;
6708 case KEY_NEED_UNLINK:
6709 case KEY_SYSADMIN_OVERRIDE:
6710 case KEY_AUTHTOKEN_OVERRIDE:
6711 case KEY_DEFER_PERM_CHECK:
6712 return 0;
6713 default:
6714 WARN_ON(1);
6715 return -EPERM;
6716
6717 }
6718
6719 sid = cred_sid(cred);
6720 key = key_ref_to_ptr(key_ref);
6721 ksec = selinux_key(key);
6722
6723 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
6724 }
6725
selinux_key_getsecurity(struct key * key,char ** _buffer)6726 static int selinux_key_getsecurity(struct key *key, char **_buffer)
6727 {
6728 struct key_security_struct *ksec = selinux_key(key);
6729 char *context = NULL;
6730 unsigned len;
6731 int rc;
6732
6733 rc = security_sid_to_context(ksec->sid,
6734 &context, &len);
6735 if (!rc)
6736 rc = len;
6737 *_buffer = context;
6738 return rc;
6739 }
6740
6741 #ifdef CONFIG_KEY_NOTIFICATIONS
selinux_watch_key(struct key * key)6742 static int selinux_watch_key(struct key *key)
6743 {
6744 struct key_security_struct *ksec = selinux_key(key);
6745 u32 sid = current_sid();
6746
6747 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, KEY__VIEW, NULL);
6748 }
6749 #endif
6750 #endif
6751
6752 #ifdef CONFIG_SECURITY_INFINIBAND
selinux_ib_pkey_access(void * ib_sec,u64 subnet_prefix,u16 pkey_val)6753 static int selinux_ib_pkey_access(void *ib_sec, u64 subnet_prefix, u16 pkey_val)
6754 {
6755 struct common_audit_data ad;
6756 int err;
6757 u32 sid = 0;
6758 struct ib_security_struct *sec = ib_sec;
6759 struct lsm_ibpkey_audit ibpkey;
6760
6761 err = sel_ib_pkey_sid(subnet_prefix, pkey_val, &sid);
6762 if (err)
6763 return err;
6764
6765 ad.type = LSM_AUDIT_DATA_IBPKEY;
6766 ibpkey.subnet_prefix = subnet_prefix;
6767 ibpkey.pkey = pkey_val;
6768 ad.u.ibpkey = &ibpkey;
6769 return avc_has_perm(sec->sid, sid,
6770 SECCLASS_INFINIBAND_PKEY,
6771 INFINIBAND_PKEY__ACCESS, &ad);
6772 }
6773
selinux_ib_endport_manage_subnet(void * ib_sec,const char * dev_name,u8 port_num)6774 static int selinux_ib_endport_manage_subnet(void *ib_sec, const char *dev_name,
6775 u8 port_num)
6776 {
6777 struct common_audit_data ad;
6778 int err;
6779 u32 sid = 0;
6780 struct ib_security_struct *sec = ib_sec;
6781 struct lsm_ibendport_audit ibendport;
6782
6783 err = security_ib_endport_sid(dev_name, port_num,
6784 &sid);
6785
6786 if (err)
6787 return err;
6788
6789 ad.type = LSM_AUDIT_DATA_IBENDPORT;
6790 ibendport.dev_name = dev_name;
6791 ibendport.port = port_num;
6792 ad.u.ibendport = &ibendport;
6793 return avc_has_perm(sec->sid, sid,
6794 SECCLASS_INFINIBAND_ENDPORT,
6795 INFINIBAND_ENDPORT__MANAGE_SUBNET, &ad);
6796 }
6797
selinux_ib_alloc_security(void * ib_sec)6798 static int selinux_ib_alloc_security(void *ib_sec)
6799 {
6800 struct ib_security_struct *sec = selinux_ib(ib_sec);
6801
6802 sec->sid = current_sid();
6803 return 0;
6804 }
6805 #endif
6806
6807 #ifdef CONFIG_BPF_SYSCALL
selinux_bpf(int cmd,union bpf_attr * attr,unsigned int size)6808 static int selinux_bpf(int cmd, union bpf_attr *attr,
6809 unsigned int size)
6810 {
6811 u32 sid = current_sid();
6812 int ret;
6813
6814 switch (cmd) {
6815 case BPF_MAP_CREATE:
6816 ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__MAP_CREATE,
6817 NULL);
6818 break;
6819 case BPF_PROG_LOAD:
6820 ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__PROG_LOAD,
6821 NULL);
6822 break;
6823 default:
6824 ret = 0;
6825 break;
6826 }
6827
6828 return ret;
6829 }
6830
bpf_map_fmode_to_av(fmode_t fmode)6831 static u32 bpf_map_fmode_to_av(fmode_t fmode)
6832 {
6833 u32 av = 0;
6834
6835 if (fmode & FMODE_READ)
6836 av |= BPF__MAP_READ;
6837 if (fmode & FMODE_WRITE)
6838 av |= BPF__MAP_WRITE;
6839 return av;
6840 }
6841
6842 /* This function will check the file pass through unix socket or binder to see
6843 * if it is a bpf related object. And apply corresponding checks on the bpf
6844 * object based on the type. The bpf maps and programs, not like other files and
6845 * socket, are using a shared anonymous inode inside the kernel as their inode.
6846 * So checking that inode cannot identify if the process have privilege to
6847 * access the bpf object and that's why we have to add this additional check in
6848 * selinux_file_receive and selinux_binder_transfer_files.
6849 */
bpf_fd_pass(const struct file * file,u32 sid)6850 static int bpf_fd_pass(const struct file *file, u32 sid)
6851 {
6852 struct bpf_security_struct *bpfsec;
6853 struct bpf_prog *prog;
6854 struct bpf_map *map;
6855 int ret;
6856
6857 if (file->f_op == &bpf_map_fops) {
6858 map = file->private_data;
6859 bpfsec = map->security;
6860 ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6861 bpf_map_fmode_to_av(file->f_mode), NULL);
6862 if (ret)
6863 return ret;
6864 } else if (file->f_op == &bpf_prog_fops) {
6865 prog = file->private_data;
6866 bpfsec = prog->aux->security;
6867 ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6868 BPF__PROG_RUN, NULL);
6869 if (ret)
6870 return ret;
6871 }
6872 return 0;
6873 }
6874
selinux_bpf_map(struct bpf_map * map,fmode_t fmode)6875 static int selinux_bpf_map(struct bpf_map *map, fmode_t fmode)
6876 {
6877 u32 sid = current_sid();
6878 struct bpf_security_struct *bpfsec;
6879
6880 bpfsec = map->security;
6881 return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6882 bpf_map_fmode_to_av(fmode), NULL);
6883 }
6884
selinux_bpf_prog(struct bpf_prog * prog)6885 static int selinux_bpf_prog(struct bpf_prog *prog)
6886 {
6887 u32 sid = current_sid();
6888 struct bpf_security_struct *bpfsec;
6889
6890 bpfsec = prog->aux->security;
6891 return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6892 BPF__PROG_RUN, NULL);
6893 }
6894
selinux_bpf_map_create(struct bpf_map * map,union bpf_attr * attr,struct bpf_token * token)6895 static int selinux_bpf_map_create(struct bpf_map *map, union bpf_attr *attr,
6896 struct bpf_token *token)
6897 {
6898 struct bpf_security_struct *bpfsec;
6899
6900 bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
6901 if (!bpfsec)
6902 return -ENOMEM;
6903
6904 bpfsec->sid = current_sid();
6905 map->security = bpfsec;
6906
6907 return 0;
6908 }
6909
selinux_bpf_map_free(struct bpf_map * map)6910 static void selinux_bpf_map_free(struct bpf_map *map)
6911 {
6912 struct bpf_security_struct *bpfsec = map->security;
6913
6914 map->security = NULL;
6915 kfree(bpfsec);
6916 }
6917
selinux_bpf_prog_load(struct bpf_prog * prog,union bpf_attr * attr,struct bpf_token * token)6918 static int selinux_bpf_prog_load(struct bpf_prog *prog, union bpf_attr *attr,
6919 struct bpf_token *token)
6920 {
6921 struct bpf_security_struct *bpfsec;
6922
6923 bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
6924 if (!bpfsec)
6925 return -ENOMEM;
6926
6927 bpfsec->sid = current_sid();
6928 prog->aux->security = bpfsec;
6929
6930 return 0;
6931 }
6932
selinux_bpf_prog_free(struct bpf_prog * prog)6933 static void selinux_bpf_prog_free(struct bpf_prog *prog)
6934 {
6935 struct bpf_security_struct *bpfsec = prog->aux->security;
6936
6937 prog->aux->security = NULL;
6938 kfree(bpfsec);
6939 }
6940
selinux_bpf_token_create(struct bpf_token * token,union bpf_attr * attr,const struct path * path)6941 static int selinux_bpf_token_create(struct bpf_token *token, union bpf_attr *attr,
6942 const struct path *path)
6943 {
6944 struct bpf_security_struct *bpfsec;
6945
6946 bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
6947 if (!bpfsec)
6948 return -ENOMEM;
6949
6950 bpfsec->sid = current_sid();
6951 token->security = bpfsec;
6952
6953 return 0;
6954 }
6955
selinux_bpf_token_free(struct bpf_token * token)6956 static void selinux_bpf_token_free(struct bpf_token *token)
6957 {
6958 struct bpf_security_struct *bpfsec = token->security;
6959
6960 token->security = NULL;
6961 kfree(bpfsec);
6962 }
6963 #endif
6964
6965 struct lsm_blob_sizes selinux_blob_sizes __ro_after_init = {
6966 .lbs_cred = sizeof(struct task_security_struct),
6967 .lbs_file = sizeof(struct file_security_struct),
6968 .lbs_inode = sizeof(struct inode_security_struct),
6969 .lbs_ipc = sizeof(struct ipc_security_struct),
6970 .lbs_key = sizeof(struct key_security_struct),
6971 .lbs_msg_msg = sizeof(struct msg_security_struct),
6972 #ifdef CONFIG_PERF_EVENTS
6973 .lbs_perf_event = sizeof(struct perf_event_security_struct),
6974 #endif
6975 .lbs_sock = sizeof(struct sk_security_struct),
6976 .lbs_superblock = sizeof(struct superblock_security_struct),
6977 .lbs_xattr_count = SELINUX_INODE_INIT_XATTRS,
6978 .lbs_tun_dev = sizeof(struct tun_security_struct),
6979 .lbs_ib = sizeof(struct ib_security_struct),
6980 };
6981
6982 #ifdef CONFIG_PERF_EVENTS
selinux_perf_event_open(struct perf_event_attr * attr,int type)6983 static int selinux_perf_event_open(struct perf_event_attr *attr, int type)
6984 {
6985 u32 requested, sid = current_sid();
6986
6987 if (type == PERF_SECURITY_OPEN)
6988 requested = PERF_EVENT__OPEN;
6989 else if (type == PERF_SECURITY_CPU)
6990 requested = PERF_EVENT__CPU;
6991 else if (type == PERF_SECURITY_KERNEL)
6992 requested = PERF_EVENT__KERNEL;
6993 else if (type == PERF_SECURITY_TRACEPOINT)
6994 requested = PERF_EVENT__TRACEPOINT;
6995 else
6996 return -EINVAL;
6997
6998 return avc_has_perm(sid, sid, SECCLASS_PERF_EVENT,
6999 requested, NULL);
7000 }
7001
selinux_perf_event_alloc(struct perf_event * event)7002 static int selinux_perf_event_alloc(struct perf_event *event)
7003 {
7004 struct perf_event_security_struct *perfsec;
7005
7006 perfsec = selinux_perf_event(event->security);
7007 perfsec->sid = current_sid();
7008
7009 return 0;
7010 }
7011
selinux_perf_event_read(struct perf_event * event)7012 static int selinux_perf_event_read(struct perf_event *event)
7013 {
7014 struct perf_event_security_struct *perfsec = event->security;
7015 u32 sid = current_sid();
7016
7017 return avc_has_perm(sid, perfsec->sid,
7018 SECCLASS_PERF_EVENT, PERF_EVENT__READ, NULL);
7019 }
7020
selinux_perf_event_write(struct perf_event * event)7021 static int selinux_perf_event_write(struct perf_event *event)
7022 {
7023 struct perf_event_security_struct *perfsec = event->security;
7024 u32 sid = current_sid();
7025
7026 return avc_has_perm(sid, perfsec->sid,
7027 SECCLASS_PERF_EVENT, PERF_EVENT__WRITE, NULL);
7028 }
7029 #endif
7030
7031 #ifdef CONFIG_IO_URING
7032 /**
7033 * selinux_uring_override_creds - check the requested cred override
7034 * @new: the target creds
7035 *
7036 * Check to see if the current task is allowed to override it's credentials
7037 * to service an io_uring operation.
7038 */
selinux_uring_override_creds(const struct cred * new)7039 static int selinux_uring_override_creds(const struct cred *new)
7040 {
7041 return avc_has_perm(current_sid(), cred_sid(new),
7042 SECCLASS_IO_URING, IO_URING__OVERRIDE_CREDS, NULL);
7043 }
7044
7045 /**
7046 * selinux_uring_sqpoll - check if a io_uring polling thread can be created
7047 *
7048 * Check to see if the current task is allowed to create a new io_uring
7049 * kernel polling thread.
7050 */
selinux_uring_sqpoll(void)7051 static int selinux_uring_sqpoll(void)
7052 {
7053 u32 sid = current_sid();
7054
7055 return avc_has_perm(sid, sid,
7056 SECCLASS_IO_URING, IO_URING__SQPOLL, NULL);
7057 }
7058
7059 /**
7060 * selinux_uring_cmd - check if IORING_OP_URING_CMD is allowed
7061 * @ioucmd: the io_uring command structure
7062 *
7063 * Check to see if the current domain is allowed to execute an
7064 * IORING_OP_URING_CMD against the device/file specified in @ioucmd.
7065 *
7066 */
selinux_uring_cmd(struct io_uring_cmd * ioucmd)7067 static int selinux_uring_cmd(struct io_uring_cmd *ioucmd)
7068 {
7069 struct file *file = ioucmd->file;
7070 struct inode *inode = file_inode(file);
7071 struct inode_security_struct *isec = selinux_inode(inode);
7072 struct common_audit_data ad;
7073
7074 ad.type = LSM_AUDIT_DATA_FILE;
7075 ad.u.file = file;
7076
7077 return avc_has_perm(current_sid(), isec->sid,
7078 SECCLASS_IO_URING, IO_URING__CMD, &ad);
7079 }
7080 #endif /* CONFIG_IO_URING */
7081
7082 static const struct lsm_id selinux_lsmid = {
7083 .name = "selinux",
7084 .id = LSM_ID_SELINUX,
7085 };
7086
7087 /*
7088 * IMPORTANT NOTE: When adding new hooks, please be careful to keep this order:
7089 * 1. any hooks that don't belong to (2.) or (3.) below,
7090 * 2. hooks that both access structures allocated by other hooks, and allocate
7091 * structures that can be later accessed by other hooks (mostly "cloning"
7092 * hooks),
7093 * 3. hooks that only allocate structures that can be later accessed by other
7094 * hooks ("allocating" hooks).
7095 *
7096 * Please follow block comment delimiters in the list to keep this order.
7097 */
7098 static struct security_hook_list selinux_hooks[] __ro_after_init = {
7099 LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr),
7100 LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction),
7101 LSM_HOOK_INIT(binder_transfer_binder, selinux_binder_transfer_binder),
7102 LSM_HOOK_INIT(binder_transfer_file, selinux_binder_transfer_file),
7103
7104 LSM_HOOK_INIT(ptrace_access_check, selinux_ptrace_access_check),
7105 LSM_HOOK_INIT(ptrace_traceme, selinux_ptrace_traceme),
7106 LSM_HOOK_INIT(capget, selinux_capget),
7107 LSM_HOOK_INIT(capset, selinux_capset),
7108 LSM_HOOK_INIT(capable, selinux_capable),
7109 LSM_HOOK_INIT(quotactl, selinux_quotactl),
7110 LSM_HOOK_INIT(quota_on, selinux_quota_on),
7111 LSM_HOOK_INIT(syslog, selinux_syslog),
7112 LSM_HOOK_INIT(vm_enough_memory, selinux_vm_enough_memory),
7113
7114 LSM_HOOK_INIT(netlink_send, selinux_netlink_send),
7115
7116 LSM_HOOK_INIT(bprm_creds_for_exec, selinux_bprm_creds_for_exec),
7117 LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds),
7118 LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds),
7119
7120 LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts),
7121 LSM_HOOK_INIT(sb_mnt_opts_compat, selinux_sb_mnt_opts_compat),
7122 LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
7123 LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
7124 LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
7125 LSM_HOOK_INIT(sb_statfs, selinux_sb_statfs),
7126 LSM_HOOK_INIT(sb_mount, selinux_mount),
7127 LSM_HOOK_INIT(sb_umount, selinux_umount),
7128 LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts),
7129 LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
7130
7131 LSM_HOOK_INIT(move_mount, selinux_move_mount),
7132
7133 LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security),
7134 LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),
7135
7136 LSM_HOOK_INIT(inode_free_security, selinux_inode_free_security),
7137 LSM_HOOK_INIT(inode_init_security, selinux_inode_init_security),
7138 LSM_HOOK_INIT(inode_init_security_anon, selinux_inode_init_security_anon),
7139 LSM_HOOK_INIT(inode_create, selinux_inode_create),
7140 LSM_HOOK_INIT(inode_link, selinux_inode_link),
7141 LSM_HOOK_INIT(inode_unlink, selinux_inode_unlink),
7142 LSM_HOOK_INIT(inode_symlink, selinux_inode_symlink),
7143 LSM_HOOK_INIT(inode_mkdir, selinux_inode_mkdir),
7144 LSM_HOOK_INIT(inode_rmdir, selinux_inode_rmdir),
7145 LSM_HOOK_INIT(inode_mknod, selinux_inode_mknod),
7146 LSM_HOOK_INIT(inode_rename, selinux_inode_rename),
7147 LSM_HOOK_INIT(inode_readlink, selinux_inode_readlink),
7148 LSM_HOOK_INIT(inode_follow_link, selinux_inode_follow_link),
7149 LSM_HOOK_INIT(inode_permission, selinux_inode_permission),
7150 LSM_HOOK_INIT(inode_setattr, selinux_inode_setattr),
7151 LSM_HOOK_INIT(inode_getattr, selinux_inode_getattr),
7152 LSM_HOOK_INIT(inode_xattr_skipcap, selinux_inode_xattr_skipcap),
7153 LSM_HOOK_INIT(inode_setxattr, selinux_inode_setxattr),
7154 LSM_HOOK_INIT(inode_post_setxattr, selinux_inode_post_setxattr),
7155 LSM_HOOK_INIT(inode_getxattr, selinux_inode_getxattr),
7156 LSM_HOOK_INIT(inode_listxattr, selinux_inode_listxattr),
7157 LSM_HOOK_INIT(inode_removexattr, selinux_inode_removexattr),
7158 LSM_HOOK_INIT(inode_set_acl, selinux_inode_set_acl),
7159 LSM_HOOK_INIT(inode_get_acl, selinux_inode_get_acl),
7160 LSM_HOOK_INIT(inode_remove_acl, selinux_inode_remove_acl),
7161 LSM_HOOK_INIT(inode_getsecurity, selinux_inode_getsecurity),
7162 LSM_HOOK_INIT(inode_setsecurity, selinux_inode_setsecurity),
7163 LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity),
7164 LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid),
7165 LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
7166 LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
7167 LSM_HOOK_INIT(path_notify, selinux_path_notify),
7168
7169 LSM_HOOK_INIT(kernfs_init_security, selinux_kernfs_init_security),
7170
7171 LSM_HOOK_INIT(file_permission, selinux_file_permission),
7172 LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),
7173 LSM_HOOK_INIT(file_ioctl, selinux_file_ioctl),
7174 LSM_HOOK_INIT(file_ioctl_compat, selinux_file_ioctl_compat),
7175 LSM_HOOK_INIT(mmap_file, selinux_mmap_file),
7176 LSM_HOOK_INIT(mmap_addr, selinux_mmap_addr),
7177 LSM_HOOK_INIT(file_mprotect, selinux_file_mprotect),
7178 LSM_HOOK_INIT(file_lock, selinux_file_lock),
7179 LSM_HOOK_INIT(file_fcntl, selinux_file_fcntl),
7180 LSM_HOOK_INIT(file_set_fowner, selinux_file_set_fowner),
7181 LSM_HOOK_INIT(file_send_sigiotask, selinux_file_send_sigiotask),
7182 LSM_HOOK_INIT(file_receive, selinux_file_receive),
7183
7184 LSM_HOOK_INIT(file_open, selinux_file_open),
7185
7186 LSM_HOOK_INIT(task_alloc, selinux_task_alloc),
7187 LSM_HOOK_INIT(cred_prepare, selinux_cred_prepare),
7188 LSM_HOOK_INIT(cred_transfer, selinux_cred_transfer),
7189 LSM_HOOK_INIT(cred_getsecid, selinux_cred_getsecid),
7190 LSM_HOOK_INIT(kernel_act_as, selinux_kernel_act_as),
7191 LSM_HOOK_INIT(kernel_create_files_as, selinux_kernel_create_files_as),
7192 LSM_HOOK_INIT(kernel_module_request, selinux_kernel_module_request),
7193 LSM_HOOK_INIT(kernel_load_data, selinux_kernel_load_data),
7194 LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file),
7195 LSM_HOOK_INIT(task_setpgid, selinux_task_setpgid),
7196 LSM_HOOK_INIT(task_getpgid, selinux_task_getpgid),
7197 LSM_HOOK_INIT(task_getsid, selinux_task_getsid),
7198 LSM_HOOK_INIT(current_getsecid_subj, selinux_current_getsecid_subj),
7199 LSM_HOOK_INIT(task_getsecid_obj, selinux_task_getsecid_obj),
7200 LSM_HOOK_INIT(task_setnice, selinux_task_setnice),
7201 LSM_HOOK_INIT(task_setioprio, selinux_task_setioprio),
7202 LSM_HOOK_INIT(task_getioprio, selinux_task_getioprio),
7203 LSM_HOOK_INIT(task_prlimit, selinux_task_prlimit),
7204 LSM_HOOK_INIT(task_setrlimit, selinux_task_setrlimit),
7205 LSM_HOOK_INIT(task_setscheduler, selinux_task_setscheduler),
7206 LSM_HOOK_INIT(task_getscheduler, selinux_task_getscheduler),
7207 LSM_HOOK_INIT(task_movememory, selinux_task_movememory),
7208 LSM_HOOK_INIT(task_kill, selinux_task_kill),
7209 LSM_HOOK_INIT(task_to_inode, selinux_task_to_inode),
7210 LSM_HOOK_INIT(userns_create, selinux_userns_create),
7211
7212 LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission),
7213 LSM_HOOK_INIT(ipc_getsecid, selinux_ipc_getsecid),
7214
7215 LSM_HOOK_INIT(msg_queue_associate, selinux_msg_queue_associate),
7216 LSM_HOOK_INIT(msg_queue_msgctl, selinux_msg_queue_msgctl),
7217 LSM_HOOK_INIT(msg_queue_msgsnd, selinux_msg_queue_msgsnd),
7218 LSM_HOOK_INIT(msg_queue_msgrcv, selinux_msg_queue_msgrcv),
7219
7220 LSM_HOOK_INIT(shm_associate, selinux_shm_associate),
7221 LSM_HOOK_INIT(shm_shmctl, selinux_shm_shmctl),
7222 LSM_HOOK_INIT(shm_shmat, selinux_shm_shmat),
7223
7224 LSM_HOOK_INIT(sem_associate, selinux_sem_associate),
7225 LSM_HOOK_INIT(sem_semctl, selinux_sem_semctl),
7226 LSM_HOOK_INIT(sem_semop, selinux_sem_semop),
7227
7228 LSM_HOOK_INIT(d_instantiate, selinux_d_instantiate),
7229
7230 LSM_HOOK_INIT(getselfattr, selinux_getselfattr),
7231 LSM_HOOK_INIT(setselfattr, selinux_setselfattr),
7232 LSM_HOOK_INIT(getprocattr, selinux_getprocattr),
7233 LSM_HOOK_INIT(setprocattr, selinux_setprocattr),
7234
7235 LSM_HOOK_INIT(ismaclabel, selinux_ismaclabel),
7236 LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid),
7237 LSM_HOOK_INIT(release_secctx, selinux_release_secctx),
7238 LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx),
7239 LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx),
7240 LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx),
7241
7242 LSM_HOOK_INIT(unix_stream_connect, selinux_socket_unix_stream_connect),
7243 LSM_HOOK_INIT(unix_may_send, selinux_socket_unix_may_send),
7244
7245 LSM_HOOK_INIT(socket_create, selinux_socket_create),
7246 LSM_HOOK_INIT(socket_post_create, selinux_socket_post_create),
7247 LSM_HOOK_INIT(socket_socketpair, selinux_socket_socketpair),
7248 LSM_HOOK_INIT(socket_bind, selinux_socket_bind),
7249 LSM_HOOK_INIT(socket_connect, selinux_socket_connect),
7250 LSM_HOOK_INIT(socket_listen, selinux_socket_listen),
7251 LSM_HOOK_INIT(socket_accept, selinux_socket_accept),
7252 LSM_HOOK_INIT(socket_sendmsg, selinux_socket_sendmsg),
7253 LSM_HOOK_INIT(socket_recvmsg, selinux_socket_recvmsg),
7254 LSM_HOOK_INIT(socket_getsockname, selinux_socket_getsockname),
7255 LSM_HOOK_INIT(socket_getpeername, selinux_socket_getpeername),
7256 LSM_HOOK_INIT(socket_getsockopt, selinux_socket_getsockopt),
7257 LSM_HOOK_INIT(socket_setsockopt, selinux_socket_setsockopt),
7258 LSM_HOOK_INIT(socket_shutdown, selinux_socket_shutdown),
7259 LSM_HOOK_INIT(socket_sock_rcv_skb, selinux_socket_sock_rcv_skb),
7260 LSM_HOOK_INIT(socket_getpeersec_stream,
7261 selinux_socket_getpeersec_stream),
7262 LSM_HOOK_INIT(socket_getpeersec_dgram, selinux_socket_getpeersec_dgram),
7263 LSM_HOOK_INIT(sk_free_security, selinux_sk_free_security),
7264 LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security),
7265 LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid),
7266 LSM_HOOK_INIT(sock_graft, selinux_sock_graft),
7267 LSM_HOOK_INIT(sctp_assoc_request, selinux_sctp_assoc_request),
7268 LSM_HOOK_INIT(sctp_sk_clone, selinux_sctp_sk_clone),
7269 LSM_HOOK_INIT(sctp_bind_connect, selinux_sctp_bind_connect),
7270 LSM_HOOK_INIT(sctp_assoc_established, selinux_sctp_assoc_established),
7271 LSM_HOOK_INIT(mptcp_add_subflow, selinux_mptcp_add_subflow),
7272 LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request),
7273 LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone),
7274 LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established),
7275 LSM_HOOK_INIT(secmark_relabel_packet, selinux_secmark_relabel_packet),
7276 LSM_HOOK_INIT(secmark_refcount_inc, selinux_secmark_refcount_inc),
7277 LSM_HOOK_INIT(secmark_refcount_dec, selinux_secmark_refcount_dec),
7278 LSM_HOOK_INIT(req_classify_flow, selinux_req_classify_flow),
7279 LSM_HOOK_INIT(tun_dev_create, selinux_tun_dev_create),
7280 LSM_HOOK_INIT(tun_dev_attach_queue, selinux_tun_dev_attach_queue),
7281 LSM_HOOK_INIT(tun_dev_attach, selinux_tun_dev_attach),
7282 LSM_HOOK_INIT(tun_dev_open, selinux_tun_dev_open),
7283 #ifdef CONFIG_SECURITY_INFINIBAND
7284 LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access),
7285 LSM_HOOK_INIT(ib_endport_manage_subnet,
7286 selinux_ib_endport_manage_subnet),
7287 #endif
7288 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7289 LSM_HOOK_INIT(xfrm_policy_free_security, selinux_xfrm_policy_free),
7290 LSM_HOOK_INIT(xfrm_policy_delete_security, selinux_xfrm_policy_delete),
7291 LSM_HOOK_INIT(xfrm_state_free_security, selinux_xfrm_state_free),
7292 LSM_HOOK_INIT(xfrm_state_delete_security, selinux_xfrm_state_delete),
7293 LSM_HOOK_INIT(xfrm_policy_lookup, selinux_xfrm_policy_lookup),
7294 LSM_HOOK_INIT(xfrm_state_pol_flow_match,
7295 selinux_xfrm_state_pol_flow_match),
7296 LSM_HOOK_INIT(xfrm_decode_session, selinux_xfrm_decode_session),
7297 #endif
7298
7299 #ifdef CONFIG_KEYS
7300 LSM_HOOK_INIT(key_permission, selinux_key_permission),
7301 LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity),
7302 #ifdef CONFIG_KEY_NOTIFICATIONS
7303 LSM_HOOK_INIT(watch_key, selinux_watch_key),
7304 #endif
7305 #endif
7306
7307 #ifdef CONFIG_AUDIT
7308 LSM_HOOK_INIT(audit_rule_known, selinux_audit_rule_known),
7309 LSM_HOOK_INIT(audit_rule_match, selinux_audit_rule_match),
7310 LSM_HOOK_INIT(audit_rule_free, selinux_audit_rule_free),
7311 #endif
7312
7313 #ifdef CONFIG_BPF_SYSCALL
7314 LSM_HOOK_INIT(bpf, selinux_bpf),
7315 LSM_HOOK_INIT(bpf_map, selinux_bpf_map),
7316 LSM_HOOK_INIT(bpf_prog, selinux_bpf_prog),
7317 LSM_HOOK_INIT(bpf_map_free, selinux_bpf_map_free),
7318 LSM_HOOK_INIT(bpf_prog_free, selinux_bpf_prog_free),
7319 LSM_HOOK_INIT(bpf_token_free, selinux_bpf_token_free),
7320 #endif
7321
7322 #ifdef CONFIG_PERF_EVENTS
7323 LSM_HOOK_INIT(perf_event_open, selinux_perf_event_open),
7324 LSM_HOOK_INIT(perf_event_read, selinux_perf_event_read),
7325 LSM_HOOK_INIT(perf_event_write, selinux_perf_event_write),
7326 #endif
7327
7328 #ifdef CONFIG_IO_URING
7329 LSM_HOOK_INIT(uring_override_creds, selinux_uring_override_creds),
7330 LSM_HOOK_INIT(uring_sqpoll, selinux_uring_sqpoll),
7331 LSM_HOOK_INIT(uring_cmd, selinux_uring_cmd),
7332 #endif
7333
7334 /*
7335 * PUT "CLONING" (ACCESSING + ALLOCATING) HOOKS HERE
7336 */
7337 LSM_HOOK_INIT(fs_context_submount, selinux_fs_context_submount),
7338 LSM_HOOK_INIT(fs_context_dup, selinux_fs_context_dup),
7339 LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param),
7340 LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts),
7341 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7342 LSM_HOOK_INIT(xfrm_policy_clone_security, selinux_xfrm_policy_clone),
7343 #endif
7344
7345 /*
7346 * PUT "ALLOCATING" HOOKS HERE
7347 */
7348 LSM_HOOK_INIT(msg_msg_alloc_security, selinux_msg_msg_alloc_security),
7349 LSM_HOOK_INIT(msg_queue_alloc_security,
7350 selinux_msg_queue_alloc_security),
7351 LSM_HOOK_INIT(shm_alloc_security, selinux_shm_alloc_security),
7352 LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security),
7353 LSM_HOOK_INIT(inode_alloc_security, selinux_inode_alloc_security),
7354 LSM_HOOK_INIT(sem_alloc_security, selinux_sem_alloc_security),
7355 LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx),
7356 LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx),
7357 LSM_HOOK_INIT(sk_alloc_security, selinux_sk_alloc_security),
7358 LSM_HOOK_INIT(tun_dev_alloc_security, selinux_tun_dev_alloc_security),
7359 #ifdef CONFIG_SECURITY_INFINIBAND
7360 LSM_HOOK_INIT(ib_alloc_security, selinux_ib_alloc_security),
7361 #endif
7362 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7363 LSM_HOOK_INIT(xfrm_policy_alloc_security, selinux_xfrm_policy_alloc),
7364 LSM_HOOK_INIT(xfrm_state_alloc, selinux_xfrm_state_alloc),
7365 LSM_HOOK_INIT(xfrm_state_alloc_acquire,
7366 selinux_xfrm_state_alloc_acquire),
7367 #endif
7368 #ifdef CONFIG_KEYS
7369 LSM_HOOK_INIT(key_alloc, selinux_key_alloc),
7370 #endif
7371 #ifdef CONFIG_AUDIT
7372 LSM_HOOK_INIT(audit_rule_init, selinux_audit_rule_init),
7373 #endif
7374 #ifdef CONFIG_BPF_SYSCALL
7375 LSM_HOOK_INIT(bpf_map_create, selinux_bpf_map_create),
7376 LSM_HOOK_INIT(bpf_prog_load, selinux_bpf_prog_load),
7377 LSM_HOOK_INIT(bpf_token_create, selinux_bpf_token_create),
7378 #endif
7379 #ifdef CONFIG_PERF_EVENTS
7380 LSM_HOOK_INIT(perf_event_alloc, selinux_perf_event_alloc),
7381 #endif
7382 };
7383
selinux_init(void)7384 static __init int selinux_init(void)
7385 {
7386 pr_info("SELinux: Initializing.\n");
7387
7388 memset(&selinux_state, 0, sizeof(selinux_state));
7389 enforcing_set(selinux_enforcing_boot);
7390 selinux_avc_init();
7391 mutex_init(&selinux_state.status_lock);
7392 mutex_init(&selinux_state.policy_mutex);
7393
7394 /* Set the security state for the initial task. */
7395 cred_init_security();
7396
7397 default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
7398 if (!default_noexec)
7399 pr_notice("SELinux: virtual memory is executable by default\n");
7400
7401 avc_init();
7402
7403 avtab_cache_init();
7404
7405 ebitmap_cache_init();
7406
7407 hashtab_cache_init();
7408
7409 security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks),
7410 &selinux_lsmid);
7411
7412 if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
7413 panic("SELinux: Unable to register AVC netcache callback\n");
7414
7415 if (avc_add_callback(selinux_lsm_notifier_avc_callback, AVC_CALLBACK_RESET))
7416 panic("SELinux: Unable to register AVC LSM notifier callback\n");
7417
7418 if (selinux_enforcing_boot)
7419 pr_debug("SELinux: Starting in enforcing mode\n");
7420 else
7421 pr_debug("SELinux: Starting in permissive mode\n");
7422
7423 fs_validate_description("selinux", selinux_fs_parameters);
7424
7425 return 0;
7426 }
7427
delayed_superblock_init(struct super_block * sb,void * unused)7428 static void delayed_superblock_init(struct super_block *sb, void *unused)
7429 {
7430 selinux_set_mnt_opts(sb, NULL, 0, NULL);
7431 }
7432
selinux_complete_init(void)7433 void selinux_complete_init(void)
7434 {
7435 pr_debug("SELinux: Completing initialization.\n");
7436
7437 /* Set up any superblocks initialized prior to the policy load. */
7438 pr_debug("SELinux: Setting up existing superblocks.\n");
7439 iterate_supers(delayed_superblock_init, NULL);
7440 }
7441
7442 /* SELinux requires early initialization in order to label
7443 all processes and objects when they are created. */
7444 DEFINE_LSM(selinux) = {
7445 .name = "selinux",
7446 .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
7447 .enabled = &selinux_enabled_boot,
7448 .blobs = &selinux_blob_sizes,
7449 .init = selinux_init,
7450 };
7451
7452 #if defined(CONFIG_NETFILTER)
7453 static const struct nf_hook_ops selinux_nf_ops[] = {
7454 {
7455 .hook = selinux_ip_postroute,
7456 .pf = NFPROTO_IPV4,
7457 .hooknum = NF_INET_POST_ROUTING,
7458 .priority = NF_IP_PRI_SELINUX_LAST,
7459 },
7460 {
7461 .hook = selinux_ip_forward,
7462 .pf = NFPROTO_IPV4,
7463 .hooknum = NF_INET_FORWARD,
7464 .priority = NF_IP_PRI_SELINUX_FIRST,
7465 },
7466 {
7467 .hook = selinux_ip_output,
7468 .pf = NFPROTO_IPV4,
7469 .hooknum = NF_INET_LOCAL_OUT,
7470 .priority = NF_IP_PRI_SELINUX_FIRST,
7471 },
7472 #if IS_ENABLED(CONFIG_IPV6)
7473 {
7474 .hook = selinux_ip_postroute,
7475 .pf = NFPROTO_IPV6,
7476 .hooknum = NF_INET_POST_ROUTING,
7477 .priority = NF_IP6_PRI_SELINUX_LAST,
7478 },
7479 {
7480 .hook = selinux_ip_forward,
7481 .pf = NFPROTO_IPV6,
7482 .hooknum = NF_INET_FORWARD,
7483 .priority = NF_IP6_PRI_SELINUX_FIRST,
7484 },
7485 {
7486 .hook = selinux_ip_output,
7487 .pf = NFPROTO_IPV6,
7488 .hooknum = NF_INET_LOCAL_OUT,
7489 .priority = NF_IP6_PRI_SELINUX_FIRST,
7490 },
7491 #endif /* IPV6 */
7492 };
7493
selinux_nf_register(struct net * net)7494 static int __net_init selinux_nf_register(struct net *net)
7495 {
7496 return nf_register_net_hooks(net, selinux_nf_ops,
7497 ARRAY_SIZE(selinux_nf_ops));
7498 }
7499
selinux_nf_unregister(struct net * net)7500 static void __net_exit selinux_nf_unregister(struct net *net)
7501 {
7502 nf_unregister_net_hooks(net, selinux_nf_ops,
7503 ARRAY_SIZE(selinux_nf_ops));
7504 }
7505
7506 static struct pernet_operations selinux_net_ops = {
7507 .init = selinux_nf_register,
7508 .exit = selinux_nf_unregister,
7509 };
7510
selinux_nf_ip_init(void)7511 static int __init selinux_nf_ip_init(void)
7512 {
7513 int err;
7514
7515 if (!selinux_enabled_boot)
7516 return 0;
7517
7518 pr_debug("SELinux: Registering netfilter hooks\n");
7519
7520 err = register_pernet_subsys(&selinux_net_ops);
7521 if (err)
7522 panic("SELinux: register_pernet_subsys: error %d\n", err);
7523
7524 return 0;
7525 }
7526 __initcall(selinux_nf_ip_init);
7527 #endif /* CONFIG_NETFILTER */
7528