1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * NSA Security-Enhanced Linux (SELinux) security module
4 *
5 * This file contains the SELinux hook function implementations.
6 *
7 * Authors: Stephen Smalley, <sds@tycho.nsa.gov>
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/tracehook.h>
29 #include <linux/errno.h>
30 #include <linux/sched/signal.h>
31 #include <linux/sched/task.h>
32 #include <linux/lsm_hooks.h>
33 #include <linux/xattr.h>
34 #include <linux/capability.h>
35 #include <linux/unistd.h>
36 #include <linux/mm.h>
37 #include <linux/mman.h>
38 #include <linux/slab.h>
39 #include <linux/pagemap.h>
40 #include <linux/proc_fs.h>
41 #include <linux/swap.h>
42 #include <linux/spinlock.h>
43 #include <linux/syscalls.h>
44 #include <linux/dcache.h>
45 #include <linux/file.h>
46 #include <linux/fdtable.h>
47 #include <linux/namei.h>
48 #include <linux/mount.h>
49 #include <linux/fs_context.h>
50 #include <linux/fs_parser.h>
51 #include <linux/netfilter_ipv4.h>
52 #include <linux/netfilter_ipv6.h>
53 #include <linux/tty.h>
54 #include <net/icmp.h>
55 #include <net/ip.h> /* for local_port_range[] */
56 #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
57 #include <net/inet_connection_sock.h>
58 #include <net/net_namespace.h>
59 #include <net/netlabel.h>
60 #include <linux/uaccess.h>
61 #include <asm/ioctls.h>
62 #include <linux/atomic.h>
63 #include <linux/bitops.h>
64 #include <linux/interrupt.h>
65 #include <linux/netdevice.h> /* for network interface checks */
66 #include <net/netlink.h>
67 #include <linux/tcp.h>
68 #include <linux/udp.h>
69 #include <linux/dccp.h>
70 #include <linux/sctp.h>
71 #include <net/sctp/structs.h>
72 #include <linux/quota.h>
73 #include <linux/un.h> /* for Unix socket types */
74 #include <net/af_unix.h> /* for Unix socket types */
75 #include <linux/parser.h>
76 #include <linux/nfs_mount.h>
77 #include <net/ipv6.h>
78 #include <linux/hugetlb.h>
79 #include <linux/personality.h>
80 #include <linux/audit.h>
81 #include <linux/string.h>
82 #include <linux/mutex.h>
83 #include <linux/posix-timers.h>
84 #include <linux/syslog.h>
85 #include <linux/user_namespace.h>
86 #include <linux/export.h>
87 #include <linux/msg.h>
88 #include <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
96 #include "avc.h"
97 #include "objsec.h"
98 #include "netif.h"
99 #include "netnode.h"
100 #include "netport.h"
101 #include "ibpkey.h"
102 #include "xfrm.h"
103 #include "netlabel.h"
104 #include "audit.h"
105 #include "avc_ss.h"
106
107 struct selinux_state selinux_state;
108
109 /* SECMARK reference count */
110 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
111
112 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
113 static int selinux_enforcing_boot __initdata;
114
enforcing_setup(char * str)115 static int __init enforcing_setup(char *str)
116 {
117 unsigned long enforcing;
118 if (!kstrtoul(str, 0, &enforcing))
119 selinux_enforcing_boot = enforcing ? 1 : 0;
120 return 1;
121 }
122 __setup("enforcing=", enforcing_setup);
123 #else
124 #define selinux_enforcing_boot 1
125 #endif
126
127 int selinux_enabled_boot __initdata = 1;
128 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
selinux_enabled_setup(char * str)129 static int __init selinux_enabled_setup(char *str)
130 {
131 unsigned long enabled;
132 if (!kstrtoul(str, 0, &enabled))
133 selinux_enabled_boot = enabled ? 1 : 0;
134 return 1;
135 }
136 __setup("selinux=", selinux_enabled_setup);
137 #endif
138
139 static unsigned int selinux_checkreqprot_boot =
140 CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
141
checkreqprot_setup(char * str)142 static int __init checkreqprot_setup(char *str)
143 {
144 unsigned long checkreqprot;
145
146 if (!kstrtoul(str, 0, &checkreqprot)) {
147 selinux_checkreqprot_boot = checkreqprot ? 1 : 0;
148 if (checkreqprot)
149 pr_warn("SELinux: checkreqprot set to 1 via kernel parameter. This is deprecated and will be rejected in a future kernel release.\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 cred *cred = (struct cred *) current->real_cred;
215 struct task_security_struct *tsec;
216
217 tsec = selinux_cred(cred);
218 tsec->osid = tsec->sid = SECINITSID_KERNEL;
219 }
220
221 /*
222 * get the security ID of a set of credentials
223 */
cred_sid(const struct cred * cred)224 static inline u32 cred_sid(const struct cred *cred)
225 {
226 const struct task_security_struct *tsec;
227
228 tsec = selinux_cred(cred);
229 return tsec->sid;
230 }
231
232 /*
233 * get the objective security ID of a task
234 */
task_sid(const struct task_struct * task)235 static inline u32 task_sid(const struct task_struct *task)
236 {
237 u32 sid;
238
239 rcu_read_lock();
240 sid = cred_sid(__task_cred(task));
241 rcu_read_unlock();
242 return sid;
243 }
244
245 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
246
247 /*
248 * Try reloading inode security labels that have been marked as invalid. The
249 * @may_sleep parameter indicates when sleeping and thus reloading labels is
250 * allowed; when set to false, returns -ECHILD when the label is
251 * invalid. The @dentry parameter should be set to a dentry of the inode.
252 */
__inode_security_revalidate(struct inode * inode,struct dentry * dentry,bool may_sleep)253 static int __inode_security_revalidate(struct inode *inode,
254 struct dentry *dentry,
255 bool may_sleep)
256 {
257 struct inode_security_struct *isec = selinux_inode(inode);
258
259 might_sleep_if(may_sleep);
260
261 if (selinux_initialized(&selinux_state) &&
262 isec->initialized != LABEL_INITIALIZED) {
263 if (!may_sleep)
264 return -ECHILD;
265
266 /*
267 * Try reloading the inode security label. This will fail if
268 * @opt_dentry is NULL and no dentry for this inode can be
269 * found; in that case, continue using the old label.
270 */
271 inode_doinit_with_dentry(inode, dentry);
272 }
273 return 0;
274 }
275
inode_security_novalidate(struct inode * inode)276 static struct inode_security_struct *inode_security_novalidate(struct inode *inode)
277 {
278 return selinux_inode(inode);
279 }
280
inode_security_rcu(struct inode * inode,bool rcu)281 static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu)
282 {
283 int error;
284
285 error = __inode_security_revalidate(inode, NULL, !rcu);
286 if (error)
287 return ERR_PTR(error);
288 return selinux_inode(inode);
289 }
290
291 /*
292 * Get the security label of an inode.
293 */
inode_security(struct inode * inode)294 static struct inode_security_struct *inode_security(struct inode *inode)
295 {
296 __inode_security_revalidate(inode, NULL, true);
297 return selinux_inode(inode);
298 }
299
backing_inode_security_novalidate(struct dentry * dentry)300 static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry)
301 {
302 struct inode *inode = d_backing_inode(dentry);
303
304 return selinux_inode(inode);
305 }
306
307 /*
308 * Get the security label of a dentry's backing inode.
309 */
backing_inode_security(struct dentry * dentry)310 static struct inode_security_struct *backing_inode_security(struct dentry *dentry)
311 {
312 struct inode *inode = d_backing_inode(dentry);
313
314 __inode_security_revalidate(inode, dentry, true);
315 return selinux_inode(inode);
316 }
317
inode_free_security(struct inode * inode)318 static void inode_free_security(struct inode *inode)
319 {
320 struct inode_security_struct *isec = selinux_inode(inode);
321 struct superblock_security_struct *sbsec;
322
323 if (!isec)
324 return;
325 sbsec = inode->i_sb->s_security;
326 /*
327 * As not all inode security structures are in a list, we check for
328 * empty list outside of the lock to make sure that we won't waste
329 * time taking a lock doing nothing.
330 *
331 * The list_del_init() function can be safely called more than once.
332 * It should not be possible for this function to be called with
333 * concurrent list_add(), but for better safety against future changes
334 * in the code, we use list_empty_careful() here.
335 */
336 if (!list_empty_careful(&isec->list)) {
337 spin_lock(&sbsec->isec_lock);
338 list_del_init(&isec->list);
339 spin_unlock(&sbsec->isec_lock);
340 }
341 }
342
superblock_free_security(struct super_block * sb)343 static void superblock_free_security(struct super_block *sb)
344 {
345 struct superblock_security_struct *sbsec = sb->s_security;
346 sb->s_security = NULL;
347 kfree(sbsec);
348 }
349
350 struct selinux_mnt_opts {
351 const char *fscontext, *context, *rootcontext, *defcontext;
352 };
353
selinux_free_mnt_opts(void * mnt_opts)354 static void selinux_free_mnt_opts(void *mnt_opts)
355 {
356 struct selinux_mnt_opts *opts = mnt_opts;
357 kfree(opts->fscontext);
358 kfree(opts->context);
359 kfree(opts->rootcontext);
360 kfree(opts->defcontext);
361 kfree(opts);
362 }
363
364 enum {
365 Opt_error = -1,
366 Opt_context = 0,
367 Opt_defcontext = 1,
368 Opt_fscontext = 2,
369 Opt_rootcontext = 3,
370 Opt_seclabel = 4,
371 };
372
373 #define A(s, has_arg) {#s, sizeof(#s) - 1, Opt_##s, has_arg}
374 static struct {
375 const char *name;
376 int len;
377 int opt;
378 bool has_arg;
379 } tokens[] = {
380 A(context, true),
381 A(fscontext, true),
382 A(defcontext, true),
383 A(rootcontext, true),
384 A(seclabel, false),
385 };
386 #undef A
387
match_opt_prefix(char * s,int l,char ** arg)388 static int match_opt_prefix(char *s, int l, char **arg)
389 {
390 int i;
391
392 for (i = 0; i < ARRAY_SIZE(tokens); i++) {
393 size_t len = tokens[i].len;
394 if (len > l || memcmp(s, tokens[i].name, len))
395 continue;
396 if (tokens[i].has_arg) {
397 if (len == l || s[len] != '=')
398 continue;
399 *arg = s + len + 1;
400 } else if (len != l)
401 continue;
402 return tokens[i].opt;
403 }
404 return Opt_error;
405 }
406
407 #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
408
may_context_mount_sb_relabel(u32 sid,struct superblock_security_struct * sbsec,const struct cred * cred)409 static int may_context_mount_sb_relabel(u32 sid,
410 struct superblock_security_struct *sbsec,
411 const struct cred *cred)
412 {
413 const struct task_security_struct *tsec = selinux_cred(cred);
414 int rc;
415
416 rc = avc_has_perm(&selinux_state,
417 tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
418 FILESYSTEM__RELABELFROM, NULL);
419 if (rc)
420 return rc;
421
422 rc = avc_has_perm(&selinux_state,
423 tsec->sid, sid, SECCLASS_FILESYSTEM,
424 FILESYSTEM__RELABELTO, NULL);
425 return rc;
426 }
427
may_context_mount_inode_relabel(u32 sid,struct superblock_security_struct * sbsec,const struct cred * cred)428 static int may_context_mount_inode_relabel(u32 sid,
429 struct superblock_security_struct *sbsec,
430 const struct cred *cred)
431 {
432 const struct task_security_struct *tsec = selinux_cred(cred);
433 int rc;
434 rc = avc_has_perm(&selinux_state,
435 tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
436 FILESYSTEM__RELABELFROM, NULL);
437 if (rc)
438 return rc;
439
440 rc = avc_has_perm(&selinux_state,
441 sid, sbsec->sid, SECCLASS_FILESYSTEM,
442 FILESYSTEM__ASSOCIATE, NULL);
443 return rc;
444 }
445
selinux_is_genfs_special_handling(struct super_block * sb)446 static int selinux_is_genfs_special_handling(struct super_block *sb)
447 {
448 /* Special handling. Genfs but also in-core setxattr handler */
449 return !strcmp(sb->s_type->name, "sysfs") ||
450 !strcmp(sb->s_type->name, "pstore") ||
451 !strcmp(sb->s_type->name, "debugfs") ||
452 !strcmp(sb->s_type->name, "tracefs") ||
453 !strcmp(sb->s_type->name, "rootfs") ||
454 (selinux_policycap_cgroupseclabel() &&
455 (!strcmp(sb->s_type->name, "cgroup") ||
456 !strcmp(sb->s_type->name, "cgroup2")));
457 }
458
selinux_is_sblabel_mnt(struct super_block * sb)459 static int selinux_is_sblabel_mnt(struct super_block *sb)
460 {
461 struct superblock_security_struct *sbsec = sb->s_security;
462
463 /*
464 * IMPORTANT: Double-check logic in this function when adding a new
465 * SECURITY_FS_USE_* definition!
466 */
467 BUILD_BUG_ON(SECURITY_FS_USE_MAX != 7);
468
469 switch (sbsec->behavior) {
470 case SECURITY_FS_USE_XATTR:
471 case SECURITY_FS_USE_TRANS:
472 case SECURITY_FS_USE_TASK:
473 case SECURITY_FS_USE_NATIVE:
474 return 1;
475
476 case SECURITY_FS_USE_GENFS:
477 return selinux_is_genfs_special_handling(sb);
478
479 /* Never allow relabeling on context mounts */
480 case SECURITY_FS_USE_MNTPOINT:
481 case SECURITY_FS_USE_NONE:
482 default:
483 return 0;
484 }
485 }
486
sb_finish_set_opts(struct super_block * sb)487 static int sb_finish_set_opts(struct super_block *sb)
488 {
489 struct superblock_security_struct *sbsec = sb->s_security;
490 struct dentry *root = sb->s_root;
491 struct inode *root_inode = d_backing_inode(root);
492 int rc = 0;
493
494 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
495 /* Make sure that the xattr handler exists and that no
496 error other than -ENODATA is returned by getxattr on
497 the root directory. -ENODATA is ok, as this may be
498 the first boot of the SELinux kernel before we have
499 assigned xattr values to the filesystem. */
500 if (!(root_inode->i_opflags & IOP_XATTR)) {
501 pr_warn("SELinux: (dev %s, type %s) has no "
502 "xattr support\n", sb->s_id, sb->s_type->name);
503 rc = -EOPNOTSUPP;
504 goto out;
505 }
506
507 rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0);
508 if (rc < 0 && rc != -ENODATA) {
509 if (rc == -EOPNOTSUPP)
510 pr_warn("SELinux: (dev %s, type "
511 "%s) has no security xattr handler\n",
512 sb->s_id, sb->s_type->name);
513 else
514 pr_warn("SELinux: (dev %s, type "
515 "%s) getxattr errno %d\n", sb->s_id,
516 sb->s_type->name, -rc);
517 goto out;
518 }
519 }
520
521 sbsec->flags |= SE_SBINITIALIZED;
522
523 /*
524 * Explicitly set or clear SBLABEL_MNT. It's not sufficient to simply
525 * leave the flag untouched because sb_clone_mnt_opts might be handing
526 * us a superblock that needs the flag to be cleared.
527 */
528 if (selinux_is_sblabel_mnt(sb))
529 sbsec->flags |= SBLABEL_MNT;
530 else
531 sbsec->flags &= ~SBLABEL_MNT;
532
533 /* Initialize the root inode. */
534 rc = inode_doinit_with_dentry(root_inode, root);
535
536 /* Initialize any other inodes associated with the superblock, e.g.
537 inodes created prior to initial policy load or inodes created
538 during get_sb by a pseudo filesystem that directly
539 populates itself. */
540 spin_lock(&sbsec->isec_lock);
541 while (!list_empty(&sbsec->isec_head)) {
542 struct inode_security_struct *isec =
543 list_first_entry(&sbsec->isec_head,
544 struct inode_security_struct, list);
545 struct inode *inode = isec->inode;
546 list_del_init(&isec->list);
547 spin_unlock(&sbsec->isec_lock);
548 inode = igrab(inode);
549 if (inode) {
550 if (!IS_PRIVATE(inode))
551 inode_doinit_with_dentry(inode, NULL);
552 iput(inode);
553 }
554 spin_lock(&sbsec->isec_lock);
555 }
556 spin_unlock(&sbsec->isec_lock);
557 out:
558 return rc;
559 }
560
bad_option(struct superblock_security_struct * sbsec,char flag,u32 old_sid,u32 new_sid)561 static int bad_option(struct superblock_security_struct *sbsec, char flag,
562 u32 old_sid, u32 new_sid)
563 {
564 char mnt_flags = sbsec->flags & SE_MNTMASK;
565
566 /* check if the old mount command had the same options */
567 if (sbsec->flags & SE_SBINITIALIZED)
568 if (!(sbsec->flags & flag) ||
569 (old_sid != new_sid))
570 return 1;
571
572 /* check if we were passed the same options twice,
573 * aka someone passed context=a,context=b
574 */
575 if (!(sbsec->flags & SE_SBINITIALIZED))
576 if (mnt_flags & flag)
577 return 1;
578 return 0;
579 }
580
parse_sid(struct super_block * sb,const char * s,u32 * sid)581 static int parse_sid(struct super_block *sb, const char *s, u32 *sid)
582 {
583 int rc = security_context_str_to_sid(&selinux_state, s,
584 sid, GFP_KERNEL);
585 if (rc)
586 pr_warn("SELinux: security_context_str_to_sid"
587 "(%s) failed for (dev %s, type %s) errno=%d\n",
588 s, sb->s_id, sb->s_type->name, rc);
589 return rc;
590 }
591
592 /*
593 * Allow filesystems with binary mount data to explicitly set mount point
594 * labeling information.
595 */
selinux_set_mnt_opts(struct super_block * sb,void * mnt_opts,unsigned long kern_flags,unsigned long * set_kern_flags)596 static int selinux_set_mnt_opts(struct super_block *sb,
597 void *mnt_opts,
598 unsigned long kern_flags,
599 unsigned long *set_kern_flags)
600 {
601 const struct cred *cred = current_cred();
602 struct superblock_security_struct *sbsec = sb->s_security;
603 struct dentry *root = sbsec->sb->s_root;
604 struct selinux_mnt_opts *opts = mnt_opts;
605 struct inode_security_struct *root_isec;
606 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
607 u32 defcontext_sid = 0;
608 int rc = 0;
609
610 mutex_lock(&sbsec->lock);
611
612 if (!selinux_initialized(&selinux_state)) {
613 if (!opts) {
614 /* Defer initialization until selinux_complete_init,
615 after the initial policy is loaded and the security
616 server is ready to handle calls. */
617 goto out;
618 }
619 rc = -EINVAL;
620 pr_warn("SELinux: Unable to set superblock options "
621 "before the security server is initialized\n");
622 goto out;
623 }
624 if (kern_flags && !set_kern_flags) {
625 /* Specifying internal flags without providing a place to
626 * place the results is not allowed */
627 rc = -EINVAL;
628 goto out;
629 }
630
631 /*
632 * Binary mount data FS will come through this function twice. Once
633 * from an explicit call and once from the generic calls from the vfs.
634 * Since the generic VFS calls will not contain any security mount data
635 * we need to skip the double mount verification.
636 *
637 * This does open a hole in which we will not notice if the first
638 * mount using this sb set explict options and a second mount using
639 * this sb does not set any security options. (The first options
640 * will be used for both mounts)
641 */
642 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
643 && !opts)
644 goto out;
645
646 root_isec = backing_inode_security_novalidate(root);
647
648 /*
649 * parse the mount options, check if they are valid sids.
650 * also check if someone is trying to mount the same sb more
651 * than once with different security options.
652 */
653 if (opts) {
654 if (opts->fscontext) {
655 rc = parse_sid(sb, opts->fscontext, &fscontext_sid);
656 if (rc)
657 goto out;
658 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
659 fscontext_sid))
660 goto out_double_mount;
661 sbsec->flags |= FSCONTEXT_MNT;
662 }
663 if (opts->context) {
664 rc = parse_sid(sb, opts->context, &context_sid);
665 if (rc)
666 goto out;
667 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
668 context_sid))
669 goto out_double_mount;
670 sbsec->flags |= CONTEXT_MNT;
671 }
672 if (opts->rootcontext) {
673 rc = parse_sid(sb, opts->rootcontext, &rootcontext_sid);
674 if (rc)
675 goto out;
676 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
677 rootcontext_sid))
678 goto out_double_mount;
679 sbsec->flags |= ROOTCONTEXT_MNT;
680 }
681 if (opts->defcontext) {
682 rc = parse_sid(sb, opts->defcontext, &defcontext_sid);
683 if (rc)
684 goto out;
685 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
686 defcontext_sid))
687 goto out_double_mount;
688 sbsec->flags |= DEFCONTEXT_MNT;
689 }
690 }
691
692 if (sbsec->flags & SE_SBINITIALIZED) {
693 /* previously mounted with options, but not on this attempt? */
694 if ((sbsec->flags & SE_MNTMASK) && !opts)
695 goto out_double_mount;
696 rc = 0;
697 goto out;
698 }
699
700 if (strcmp(sb->s_type->name, "proc") == 0)
701 sbsec->flags |= SE_SBPROC | SE_SBGENFS;
702
703 if (!strcmp(sb->s_type->name, "debugfs") ||
704 !strcmp(sb->s_type->name, "tracefs") ||
705 !strcmp(sb->s_type->name, "binder") ||
706 !strcmp(sb->s_type->name, "bpf") ||
707 !strcmp(sb->s_type->name, "pstore"))
708 sbsec->flags |= SE_SBGENFS;
709
710 if (!strcmp(sb->s_type->name, "sysfs") ||
711 !strcmp(sb->s_type->name, "cgroup") ||
712 !strcmp(sb->s_type->name, "cgroup2"))
713 sbsec->flags |= SE_SBGENFS | SE_SBGENFS_XATTR;
714
715 if (!sbsec->behavior) {
716 /*
717 * Determine the labeling behavior to use for this
718 * filesystem type.
719 */
720 rc = security_fs_use(&selinux_state, sb);
721 if (rc) {
722 pr_warn("%s: security_fs_use(%s) returned %d\n",
723 __func__, sb->s_type->name, rc);
724 goto out;
725 }
726 }
727
728 /*
729 * If this is a user namespace mount and the filesystem type is not
730 * explicitly whitelisted, then no contexts are allowed on the command
731 * line and security labels must be ignored.
732 */
733 if (sb->s_user_ns != &init_user_ns &&
734 strcmp(sb->s_type->name, "tmpfs") &&
735 strcmp(sb->s_type->name, "ramfs") &&
736 strcmp(sb->s_type->name, "devpts")) {
737 if (context_sid || fscontext_sid || rootcontext_sid ||
738 defcontext_sid) {
739 rc = -EACCES;
740 goto out;
741 }
742 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
743 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
744 rc = security_transition_sid(&selinux_state,
745 current_sid(),
746 current_sid(),
747 SECCLASS_FILE, NULL,
748 &sbsec->mntpoint_sid);
749 if (rc)
750 goto out;
751 }
752 goto out_set_opts;
753 }
754
755 /* sets the context of the superblock for the fs being mounted. */
756 if (fscontext_sid) {
757 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
758 if (rc)
759 goto out;
760
761 sbsec->sid = fscontext_sid;
762 }
763
764 /*
765 * Switch to using mount point labeling behavior.
766 * sets the label used on all file below the mountpoint, and will set
767 * the superblock context if not already set.
768 */
769 if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
770 sbsec->behavior = SECURITY_FS_USE_NATIVE;
771 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
772 }
773
774 if (context_sid) {
775 if (!fscontext_sid) {
776 rc = may_context_mount_sb_relabel(context_sid, sbsec,
777 cred);
778 if (rc)
779 goto out;
780 sbsec->sid = context_sid;
781 } else {
782 rc = may_context_mount_inode_relabel(context_sid, sbsec,
783 cred);
784 if (rc)
785 goto out;
786 }
787 if (!rootcontext_sid)
788 rootcontext_sid = context_sid;
789
790 sbsec->mntpoint_sid = context_sid;
791 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
792 }
793
794 if (rootcontext_sid) {
795 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
796 cred);
797 if (rc)
798 goto out;
799
800 root_isec->sid = rootcontext_sid;
801 root_isec->initialized = LABEL_INITIALIZED;
802 }
803
804 if (defcontext_sid) {
805 if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
806 sbsec->behavior != SECURITY_FS_USE_NATIVE) {
807 rc = -EINVAL;
808 pr_warn("SELinux: defcontext option is "
809 "invalid for this filesystem type\n");
810 goto out;
811 }
812
813 if (defcontext_sid != sbsec->def_sid) {
814 rc = may_context_mount_inode_relabel(defcontext_sid,
815 sbsec, cred);
816 if (rc)
817 goto out;
818 }
819
820 sbsec->def_sid = defcontext_sid;
821 }
822
823 out_set_opts:
824 rc = sb_finish_set_opts(sb);
825 out:
826 mutex_unlock(&sbsec->lock);
827 return rc;
828 out_double_mount:
829 rc = -EINVAL;
830 pr_warn("SELinux: mount invalid. Same superblock, different "
831 "security settings for (dev %s, type %s)\n", sb->s_id,
832 sb->s_type->name);
833 goto out;
834 }
835
selinux_cmp_sb_context(const struct super_block * oldsb,const struct super_block * newsb)836 static int selinux_cmp_sb_context(const struct super_block *oldsb,
837 const struct super_block *newsb)
838 {
839 struct superblock_security_struct *old = oldsb->s_security;
840 struct superblock_security_struct *new = newsb->s_security;
841 char oldflags = old->flags & SE_MNTMASK;
842 char newflags = new->flags & SE_MNTMASK;
843
844 if (oldflags != newflags)
845 goto mismatch;
846 if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
847 goto mismatch;
848 if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
849 goto mismatch;
850 if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
851 goto mismatch;
852 if (oldflags & ROOTCONTEXT_MNT) {
853 struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root);
854 struct inode_security_struct *newroot = backing_inode_security(newsb->s_root);
855 if (oldroot->sid != newroot->sid)
856 goto mismatch;
857 }
858 return 0;
859 mismatch:
860 pr_warn("SELinux: mount invalid. Same superblock, "
861 "different security settings for (dev %s, "
862 "type %s)\n", newsb->s_id, newsb->s_type->name);
863 return -EBUSY;
864 }
865
selinux_sb_clone_mnt_opts(const struct super_block * oldsb,struct super_block * newsb,unsigned long kern_flags,unsigned long * set_kern_flags)866 static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
867 struct super_block *newsb,
868 unsigned long kern_flags,
869 unsigned long *set_kern_flags)
870 {
871 int rc = 0;
872 const struct superblock_security_struct *oldsbsec = oldsb->s_security;
873 struct superblock_security_struct *newsbsec = newsb->s_security;
874
875 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT);
876 int set_context = (oldsbsec->flags & CONTEXT_MNT);
877 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT);
878
879 /*
880 * if the parent was able to be mounted it clearly had no special lsm
881 * mount options. thus we can safely deal with this superblock later
882 */
883 if (!selinux_initialized(&selinux_state))
884 return 0;
885
886 /*
887 * Specifying internal flags without providing a place to
888 * place the results is not allowed.
889 */
890 if (kern_flags && !set_kern_flags)
891 return -EINVAL;
892
893 /* how can we clone if the old one wasn't set up?? */
894 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
895
896 /* if fs is reusing a sb, make sure that the contexts match */
897 if (newsbsec->flags & SE_SBINITIALIZED) {
898 if ((kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context)
899 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
900 return selinux_cmp_sb_context(oldsb, newsb);
901 }
902
903 mutex_lock(&newsbsec->lock);
904
905 newsbsec->flags = oldsbsec->flags;
906
907 newsbsec->sid = oldsbsec->sid;
908 newsbsec->def_sid = oldsbsec->def_sid;
909 newsbsec->behavior = oldsbsec->behavior;
910
911 if (newsbsec->behavior == SECURITY_FS_USE_NATIVE &&
912 !(kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) {
913 rc = security_fs_use(&selinux_state, newsb);
914 if (rc)
915 goto out;
916 }
917
918 if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !set_context) {
919 newsbsec->behavior = SECURITY_FS_USE_NATIVE;
920 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
921 }
922
923 if (set_context) {
924 u32 sid = oldsbsec->mntpoint_sid;
925
926 if (!set_fscontext)
927 newsbsec->sid = sid;
928 if (!set_rootcontext) {
929 struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
930 newisec->sid = sid;
931 }
932 newsbsec->mntpoint_sid = sid;
933 }
934 if (set_rootcontext) {
935 const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root);
936 struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
937
938 newisec->sid = oldisec->sid;
939 }
940
941 sb_finish_set_opts(newsb);
942 out:
943 mutex_unlock(&newsbsec->lock);
944 return rc;
945 }
946
selinux_add_opt(int token,const char * s,void ** mnt_opts)947 static int selinux_add_opt(int token, const char *s, void **mnt_opts)
948 {
949 struct selinux_mnt_opts *opts = *mnt_opts;
950
951 if (token == Opt_seclabel) /* eaten and completely ignored */
952 return 0;
953
954 if (!opts) {
955 opts = kzalloc(sizeof(struct selinux_mnt_opts), GFP_KERNEL);
956 if (!opts)
957 return -ENOMEM;
958 *mnt_opts = opts;
959 }
960 if (!s)
961 return -ENOMEM;
962 switch (token) {
963 case Opt_context:
964 if (opts->context || opts->defcontext)
965 goto Einval;
966 opts->context = s;
967 break;
968 case Opt_fscontext:
969 if (opts->fscontext)
970 goto Einval;
971 opts->fscontext = s;
972 break;
973 case Opt_rootcontext:
974 if (opts->rootcontext)
975 goto Einval;
976 opts->rootcontext = s;
977 break;
978 case Opt_defcontext:
979 if (opts->context || opts->defcontext)
980 goto Einval;
981 opts->defcontext = s;
982 break;
983 }
984 return 0;
985 Einval:
986 pr_warn(SEL_MOUNT_FAIL_MSG);
987 return -EINVAL;
988 }
989
selinux_add_mnt_opt(const char * option,const char * val,int len,void ** mnt_opts)990 static int selinux_add_mnt_opt(const char *option, const char *val, int len,
991 void **mnt_opts)
992 {
993 int token = Opt_error;
994 int rc, i;
995
996 for (i = 0; i < ARRAY_SIZE(tokens); i++) {
997 if (strcmp(option, tokens[i].name) == 0) {
998 token = tokens[i].opt;
999 break;
1000 }
1001 }
1002
1003 if (token == Opt_error)
1004 return -EINVAL;
1005
1006 if (token != Opt_seclabel) {
1007 val = kmemdup_nul(val, len, GFP_KERNEL);
1008 if (!val) {
1009 rc = -ENOMEM;
1010 goto free_opt;
1011 }
1012 }
1013 rc = selinux_add_opt(token, val, mnt_opts);
1014 if (unlikely(rc)) {
1015 kfree(val);
1016 goto free_opt;
1017 }
1018 return rc;
1019
1020 free_opt:
1021 if (*mnt_opts) {
1022 selinux_free_mnt_opts(*mnt_opts);
1023 *mnt_opts = NULL;
1024 }
1025 return rc;
1026 }
1027
show_sid(struct seq_file * m,u32 sid)1028 static int show_sid(struct seq_file *m, u32 sid)
1029 {
1030 char *context = NULL;
1031 u32 len;
1032 int rc;
1033
1034 rc = security_sid_to_context(&selinux_state, sid,
1035 &context, &len);
1036 if (!rc) {
1037 bool has_comma = context && strchr(context, ',');
1038
1039 seq_putc(m, '=');
1040 if (has_comma)
1041 seq_putc(m, '\"');
1042 seq_escape(m, context, "\"\n\\");
1043 if (has_comma)
1044 seq_putc(m, '\"');
1045 }
1046 kfree(context);
1047 return rc;
1048 }
1049
selinux_sb_show_options(struct seq_file * m,struct super_block * sb)1050 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1051 {
1052 struct superblock_security_struct *sbsec = sb->s_security;
1053 int rc;
1054
1055 if (!(sbsec->flags & SE_SBINITIALIZED))
1056 return 0;
1057
1058 if (!selinux_initialized(&selinux_state))
1059 return 0;
1060
1061 if (sbsec->flags & FSCONTEXT_MNT) {
1062 seq_putc(m, ',');
1063 seq_puts(m, FSCONTEXT_STR);
1064 rc = show_sid(m, sbsec->sid);
1065 if (rc)
1066 return rc;
1067 }
1068 if (sbsec->flags & CONTEXT_MNT) {
1069 seq_putc(m, ',');
1070 seq_puts(m, CONTEXT_STR);
1071 rc = show_sid(m, sbsec->mntpoint_sid);
1072 if (rc)
1073 return rc;
1074 }
1075 if (sbsec->flags & DEFCONTEXT_MNT) {
1076 seq_putc(m, ',');
1077 seq_puts(m, DEFCONTEXT_STR);
1078 rc = show_sid(m, sbsec->def_sid);
1079 if (rc)
1080 return rc;
1081 }
1082 if (sbsec->flags & ROOTCONTEXT_MNT) {
1083 struct dentry *root = sbsec->sb->s_root;
1084 struct inode_security_struct *isec = backing_inode_security(root);
1085 seq_putc(m, ',');
1086 seq_puts(m, ROOTCONTEXT_STR);
1087 rc = show_sid(m, isec->sid);
1088 if (rc)
1089 return rc;
1090 }
1091 if (sbsec->flags & SBLABEL_MNT) {
1092 seq_putc(m, ',');
1093 seq_puts(m, SECLABEL_STR);
1094 }
1095 return 0;
1096 }
1097
inode_mode_to_security_class(umode_t mode)1098 static inline u16 inode_mode_to_security_class(umode_t mode)
1099 {
1100 switch (mode & S_IFMT) {
1101 case S_IFSOCK:
1102 return SECCLASS_SOCK_FILE;
1103 case S_IFLNK:
1104 return SECCLASS_LNK_FILE;
1105 case S_IFREG:
1106 return SECCLASS_FILE;
1107 case S_IFBLK:
1108 return SECCLASS_BLK_FILE;
1109 case S_IFDIR:
1110 return SECCLASS_DIR;
1111 case S_IFCHR:
1112 return SECCLASS_CHR_FILE;
1113 case S_IFIFO:
1114 return SECCLASS_FIFO_FILE;
1115
1116 }
1117
1118 return SECCLASS_FILE;
1119 }
1120
default_protocol_stream(int protocol)1121 static inline int default_protocol_stream(int protocol)
1122 {
1123 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
1124 }
1125
default_protocol_dgram(int protocol)1126 static inline int default_protocol_dgram(int protocol)
1127 {
1128 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1129 }
1130
socket_type_to_security_class(int family,int type,int protocol)1131 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1132 {
1133 int extsockclass = selinux_policycap_extsockclass();
1134
1135 switch (family) {
1136 case PF_UNIX:
1137 switch (type) {
1138 case SOCK_STREAM:
1139 case SOCK_SEQPACKET:
1140 return SECCLASS_UNIX_STREAM_SOCKET;
1141 case SOCK_DGRAM:
1142 case SOCK_RAW:
1143 return SECCLASS_UNIX_DGRAM_SOCKET;
1144 }
1145 break;
1146 case PF_INET:
1147 case PF_INET6:
1148 switch (type) {
1149 case SOCK_STREAM:
1150 case SOCK_SEQPACKET:
1151 if (default_protocol_stream(protocol))
1152 return SECCLASS_TCP_SOCKET;
1153 else if (extsockclass && protocol == IPPROTO_SCTP)
1154 return SECCLASS_SCTP_SOCKET;
1155 else
1156 return SECCLASS_RAWIP_SOCKET;
1157 case SOCK_DGRAM:
1158 if (default_protocol_dgram(protocol))
1159 return SECCLASS_UDP_SOCKET;
1160 else if (extsockclass && (protocol == IPPROTO_ICMP ||
1161 protocol == IPPROTO_ICMPV6))
1162 return SECCLASS_ICMP_SOCKET;
1163 else
1164 return SECCLASS_RAWIP_SOCKET;
1165 case SOCK_DCCP:
1166 return SECCLASS_DCCP_SOCKET;
1167 default:
1168 return SECCLASS_RAWIP_SOCKET;
1169 }
1170 break;
1171 case PF_NETLINK:
1172 switch (protocol) {
1173 case NETLINK_ROUTE:
1174 return SECCLASS_NETLINK_ROUTE_SOCKET;
1175 case NETLINK_SOCK_DIAG:
1176 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1177 case NETLINK_NFLOG:
1178 return SECCLASS_NETLINK_NFLOG_SOCKET;
1179 case NETLINK_XFRM:
1180 return SECCLASS_NETLINK_XFRM_SOCKET;
1181 case NETLINK_SELINUX:
1182 return SECCLASS_NETLINK_SELINUX_SOCKET;
1183 case NETLINK_ISCSI:
1184 return SECCLASS_NETLINK_ISCSI_SOCKET;
1185 case NETLINK_AUDIT:
1186 return SECCLASS_NETLINK_AUDIT_SOCKET;
1187 case NETLINK_FIB_LOOKUP:
1188 return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET;
1189 case NETLINK_CONNECTOR:
1190 return SECCLASS_NETLINK_CONNECTOR_SOCKET;
1191 case NETLINK_NETFILTER:
1192 return SECCLASS_NETLINK_NETFILTER_SOCKET;
1193 case NETLINK_DNRTMSG:
1194 return SECCLASS_NETLINK_DNRT_SOCKET;
1195 case NETLINK_KOBJECT_UEVENT:
1196 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1197 case NETLINK_GENERIC:
1198 return SECCLASS_NETLINK_GENERIC_SOCKET;
1199 case NETLINK_SCSITRANSPORT:
1200 return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET;
1201 case NETLINK_RDMA:
1202 return SECCLASS_NETLINK_RDMA_SOCKET;
1203 case NETLINK_CRYPTO:
1204 return SECCLASS_NETLINK_CRYPTO_SOCKET;
1205 default:
1206 return SECCLASS_NETLINK_SOCKET;
1207 }
1208 case PF_PACKET:
1209 return SECCLASS_PACKET_SOCKET;
1210 case PF_KEY:
1211 return SECCLASS_KEY_SOCKET;
1212 case PF_APPLETALK:
1213 return SECCLASS_APPLETALK_SOCKET;
1214 }
1215
1216 if (extsockclass) {
1217 switch (family) {
1218 case PF_AX25:
1219 return SECCLASS_AX25_SOCKET;
1220 case PF_IPX:
1221 return SECCLASS_IPX_SOCKET;
1222 case PF_NETROM:
1223 return SECCLASS_NETROM_SOCKET;
1224 case PF_ATMPVC:
1225 return SECCLASS_ATMPVC_SOCKET;
1226 case PF_X25:
1227 return SECCLASS_X25_SOCKET;
1228 case PF_ROSE:
1229 return SECCLASS_ROSE_SOCKET;
1230 case PF_DECnet:
1231 return SECCLASS_DECNET_SOCKET;
1232 case PF_ATMSVC:
1233 return SECCLASS_ATMSVC_SOCKET;
1234 case PF_RDS:
1235 return SECCLASS_RDS_SOCKET;
1236 case PF_IRDA:
1237 return SECCLASS_IRDA_SOCKET;
1238 case PF_PPPOX:
1239 return SECCLASS_PPPOX_SOCKET;
1240 case PF_LLC:
1241 return SECCLASS_LLC_SOCKET;
1242 case PF_CAN:
1243 return SECCLASS_CAN_SOCKET;
1244 case PF_TIPC:
1245 return SECCLASS_TIPC_SOCKET;
1246 case PF_BLUETOOTH:
1247 return SECCLASS_BLUETOOTH_SOCKET;
1248 case PF_IUCV:
1249 return SECCLASS_IUCV_SOCKET;
1250 case PF_RXRPC:
1251 return SECCLASS_RXRPC_SOCKET;
1252 case PF_ISDN:
1253 return SECCLASS_ISDN_SOCKET;
1254 case PF_PHONET:
1255 return SECCLASS_PHONET_SOCKET;
1256 case PF_IEEE802154:
1257 return SECCLASS_IEEE802154_SOCKET;
1258 case PF_CAIF:
1259 return SECCLASS_CAIF_SOCKET;
1260 case PF_ALG:
1261 return SECCLASS_ALG_SOCKET;
1262 case PF_NFC:
1263 return SECCLASS_NFC_SOCKET;
1264 case PF_VSOCK:
1265 return SECCLASS_VSOCK_SOCKET;
1266 case PF_KCM:
1267 return SECCLASS_KCM_SOCKET;
1268 case PF_QIPCRTR:
1269 return SECCLASS_QIPCRTR_SOCKET;
1270 case PF_SMC:
1271 return SECCLASS_SMC_SOCKET;
1272 case PF_XDP:
1273 return SECCLASS_XDP_SOCKET;
1274 #if PF_MAX > 45
1275 #error New address family defined, please update this function.
1276 #endif
1277 }
1278 }
1279
1280 return SECCLASS_SOCKET;
1281 }
1282
selinux_genfs_get_sid(struct dentry * dentry,u16 tclass,u16 flags,u32 * sid)1283 static int selinux_genfs_get_sid(struct dentry *dentry,
1284 u16 tclass,
1285 u16 flags,
1286 u32 *sid)
1287 {
1288 int rc;
1289 struct super_block *sb = dentry->d_sb;
1290 char *buffer, *path;
1291
1292 buffer = (char *)__get_free_page(GFP_KERNEL);
1293 if (!buffer)
1294 return -ENOMEM;
1295
1296 path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1297 if (IS_ERR(path))
1298 rc = PTR_ERR(path);
1299 else {
1300 if (flags & SE_SBPROC) {
1301 /* each process gets a /proc/PID/ entry. Strip off the
1302 * PID part to get a valid selinux labeling.
1303 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1304 while (path[1] >= '0' && path[1] <= '9') {
1305 path[1] = '/';
1306 path++;
1307 }
1308 }
1309 rc = security_genfs_sid(&selinux_state, sb->s_type->name,
1310 path, tclass, sid);
1311 if (rc == -ENOENT) {
1312 /* No match in policy, mark as unlabeled. */
1313 *sid = SECINITSID_UNLABELED;
1314 rc = 0;
1315 }
1316 }
1317 free_page((unsigned long)buffer);
1318 return rc;
1319 }
1320
inode_doinit_use_xattr(struct inode * inode,struct dentry * dentry,u32 def_sid,u32 * sid)1321 static int inode_doinit_use_xattr(struct inode *inode, struct dentry *dentry,
1322 u32 def_sid, u32 *sid)
1323 {
1324 #define INITCONTEXTLEN 255
1325 char *context;
1326 unsigned int len;
1327 int rc;
1328
1329 len = INITCONTEXTLEN;
1330 context = kmalloc(len + 1, GFP_NOFS);
1331 if (!context)
1332 return -ENOMEM;
1333
1334 context[len] = '\0';
1335 rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
1336 if (rc == -ERANGE) {
1337 kfree(context);
1338
1339 /* Need a larger buffer. Query for the right size. */
1340 rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0);
1341 if (rc < 0)
1342 return rc;
1343
1344 len = rc;
1345 context = kmalloc(len + 1, GFP_NOFS);
1346 if (!context)
1347 return -ENOMEM;
1348
1349 context[len] = '\0';
1350 rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX,
1351 context, len);
1352 }
1353 if (rc < 0) {
1354 kfree(context);
1355 if (rc != -ENODATA) {
1356 pr_warn("SELinux: %s: getxattr returned %d for dev=%s ino=%ld\n",
1357 __func__, -rc, inode->i_sb->s_id, inode->i_ino);
1358 return rc;
1359 }
1360 *sid = def_sid;
1361 return 0;
1362 }
1363
1364 rc = security_context_to_sid_default(&selinux_state, context, rc, sid,
1365 def_sid, GFP_NOFS);
1366 if (rc) {
1367 char *dev = inode->i_sb->s_id;
1368 unsigned long ino = inode->i_ino;
1369
1370 if (rc == -EINVAL) {
1371 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",
1372 ino, dev, context);
1373 } else {
1374 pr_warn("SELinux: %s: context_to_sid(%s) returned %d for dev=%s ino=%ld\n",
1375 __func__, context, -rc, dev, ino);
1376 }
1377 }
1378 kfree(context);
1379 return 0;
1380 }
1381
1382 /* The inode's security attributes must be initialized before first use. */
inode_doinit_with_dentry(struct inode * inode,struct dentry * opt_dentry)1383 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1384 {
1385 struct superblock_security_struct *sbsec = NULL;
1386 struct inode_security_struct *isec = selinux_inode(inode);
1387 u32 task_sid, sid = 0;
1388 u16 sclass;
1389 struct dentry *dentry;
1390 int rc = 0;
1391
1392 if (isec->initialized == LABEL_INITIALIZED)
1393 return 0;
1394
1395 spin_lock(&isec->lock);
1396 if (isec->initialized == LABEL_INITIALIZED)
1397 goto out_unlock;
1398
1399 if (isec->sclass == SECCLASS_FILE)
1400 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1401
1402 sbsec = inode->i_sb->s_security;
1403 if (!(sbsec->flags & SE_SBINITIALIZED)) {
1404 /* Defer initialization until selinux_complete_init,
1405 after the initial policy is loaded and the security
1406 server is ready to handle calls. */
1407 spin_lock(&sbsec->isec_lock);
1408 if (list_empty(&isec->list))
1409 list_add(&isec->list, &sbsec->isec_head);
1410 spin_unlock(&sbsec->isec_lock);
1411 goto out_unlock;
1412 }
1413
1414 sclass = isec->sclass;
1415 task_sid = isec->task_sid;
1416 sid = isec->sid;
1417 isec->initialized = LABEL_PENDING;
1418 spin_unlock(&isec->lock);
1419
1420 switch (sbsec->behavior) {
1421 case SECURITY_FS_USE_NATIVE:
1422 break;
1423 case SECURITY_FS_USE_XATTR:
1424 if (!(inode->i_opflags & IOP_XATTR)) {
1425 sid = sbsec->def_sid;
1426 break;
1427 }
1428 /* Need a dentry, since the xattr API requires one.
1429 Life would be simpler if we could just pass the inode. */
1430 if (opt_dentry) {
1431 /* Called from d_instantiate or d_splice_alias. */
1432 dentry = dget(opt_dentry);
1433 } else {
1434 /*
1435 * Called from selinux_complete_init, try to find a dentry.
1436 * Some filesystems really want a connected one, so try
1437 * that first. We could split SECURITY_FS_USE_XATTR in
1438 * two, depending upon that...
1439 */
1440 dentry = d_find_alias(inode);
1441 if (!dentry)
1442 dentry = d_find_any_alias(inode);
1443 }
1444 if (!dentry) {
1445 /*
1446 * this is can be hit on boot when a file is accessed
1447 * before the policy is loaded. When we load policy we
1448 * may find inodes that have no dentry on the
1449 * sbsec->isec_head list. No reason to complain as these
1450 * will get fixed up the next time we go through
1451 * inode_doinit with a dentry, before these inodes could
1452 * be used again by userspace.
1453 */
1454 goto out_invalid;
1455 }
1456
1457 rc = inode_doinit_use_xattr(inode, dentry, sbsec->def_sid,
1458 &sid);
1459 dput(dentry);
1460 if (rc)
1461 goto out;
1462 break;
1463 case SECURITY_FS_USE_TASK:
1464 sid = task_sid;
1465 break;
1466 case SECURITY_FS_USE_TRANS:
1467 /* Default to the fs SID. */
1468 sid = sbsec->sid;
1469
1470 /* Try to obtain a transition SID. */
1471 rc = security_transition_sid(&selinux_state, task_sid, sid,
1472 sclass, NULL, &sid);
1473 if (rc)
1474 goto out;
1475 break;
1476 case SECURITY_FS_USE_MNTPOINT:
1477 sid = sbsec->mntpoint_sid;
1478 break;
1479 default:
1480 /* Default to the fs superblock SID. */
1481 sid = sbsec->sid;
1482
1483 if ((sbsec->flags & SE_SBGENFS) &&
1484 (!S_ISLNK(inode->i_mode) ||
1485 selinux_policycap_genfs_seclabel_symlinks())) {
1486 /* We must have a dentry to determine the label on
1487 * procfs inodes */
1488 if (opt_dentry) {
1489 /* Called from d_instantiate or
1490 * d_splice_alias. */
1491 dentry = dget(opt_dentry);
1492 } else {
1493 /* Called from selinux_complete_init, try to
1494 * find a dentry. Some filesystems really want
1495 * a connected one, so try that first.
1496 */
1497 dentry = d_find_alias(inode);
1498 if (!dentry)
1499 dentry = d_find_any_alias(inode);
1500 }
1501 /*
1502 * This can be hit on boot when a file is accessed
1503 * before the policy is loaded. When we load policy we
1504 * may find inodes that have no dentry on the
1505 * sbsec->isec_head list. No reason to complain as
1506 * these will get fixed up the next time we go through
1507 * inode_doinit() with a dentry, before these inodes
1508 * could be used again by userspace.
1509 */
1510 if (!dentry)
1511 goto out_invalid;
1512 rc = selinux_genfs_get_sid(dentry, sclass,
1513 sbsec->flags, &sid);
1514 if (rc) {
1515 dput(dentry);
1516 goto out;
1517 }
1518
1519 if ((sbsec->flags & SE_SBGENFS_XATTR) &&
1520 (inode->i_opflags & IOP_XATTR)) {
1521 rc = inode_doinit_use_xattr(inode, dentry,
1522 sid, &sid);
1523 if (rc) {
1524 dput(dentry);
1525 goto out;
1526 }
1527 }
1528 dput(dentry);
1529 }
1530 break;
1531 }
1532
1533 out:
1534 spin_lock(&isec->lock);
1535 if (isec->initialized == LABEL_PENDING) {
1536 if (rc) {
1537 isec->initialized = LABEL_INVALID;
1538 goto out_unlock;
1539 }
1540 isec->initialized = LABEL_INITIALIZED;
1541 isec->sid = sid;
1542 }
1543
1544 out_unlock:
1545 spin_unlock(&isec->lock);
1546 return rc;
1547
1548 out_invalid:
1549 spin_lock(&isec->lock);
1550 if (isec->initialized == LABEL_PENDING) {
1551 isec->initialized = LABEL_INVALID;
1552 isec->sid = sid;
1553 }
1554 spin_unlock(&isec->lock);
1555 return 0;
1556 }
1557
1558 /* Convert a Linux signal to an access vector. */
signal_to_av(int sig)1559 static inline u32 signal_to_av(int sig)
1560 {
1561 u32 perm = 0;
1562
1563 switch (sig) {
1564 case SIGCHLD:
1565 /* Commonly granted from child to parent. */
1566 perm = PROCESS__SIGCHLD;
1567 break;
1568 case SIGKILL:
1569 /* Cannot be caught or ignored */
1570 perm = PROCESS__SIGKILL;
1571 break;
1572 case SIGSTOP:
1573 /* Cannot be caught or ignored */
1574 perm = PROCESS__SIGSTOP;
1575 break;
1576 default:
1577 /* All other signals. */
1578 perm = PROCESS__SIGNAL;
1579 break;
1580 }
1581
1582 return perm;
1583 }
1584
1585 #if CAP_LAST_CAP > 63
1586 #error Fix SELinux to handle capabilities > 63.
1587 #endif
1588
1589 /* Check whether a task is allowed to use a capability. */
cred_has_capability(const struct cred * cred,int cap,unsigned int opts,bool initns)1590 static int cred_has_capability(const struct cred *cred,
1591 int cap, unsigned int opts, bool initns)
1592 {
1593 struct common_audit_data ad;
1594 struct av_decision avd;
1595 u16 sclass;
1596 u32 sid = cred_sid(cred);
1597 u32 av = CAP_TO_MASK(cap);
1598 int rc;
1599
1600 ad.type = LSM_AUDIT_DATA_CAP;
1601 ad.u.cap = cap;
1602
1603 switch (CAP_TO_INDEX(cap)) {
1604 case 0:
1605 sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS;
1606 break;
1607 case 1:
1608 sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS;
1609 break;
1610 default:
1611 pr_err("SELinux: out of range capability %d\n", cap);
1612 BUG();
1613 return -EINVAL;
1614 }
1615
1616 rc = avc_has_perm_noaudit(&selinux_state,
1617 sid, sid, sclass, av, 0, &avd);
1618 if (!(opts & CAP_OPT_NOAUDIT)) {
1619 int rc2 = avc_audit(&selinux_state,
1620 sid, sid, sclass, av, &avd, rc, &ad, 0);
1621 if (rc2)
1622 return rc2;
1623 }
1624 return rc;
1625 }
1626
1627 /* Check whether a task has a particular permission to an inode.
1628 The 'adp' parameter is optional and allows other audit
1629 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)1630 static int inode_has_perm(const struct cred *cred,
1631 struct inode *inode,
1632 u32 perms,
1633 struct common_audit_data *adp)
1634 {
1635 struct inode_security_struct *isec;
1636 u32 sid;
1637
1638 validate_creds(cred);
1639
1640 if (unlikely(IS_PRIVATE(inode)))
1641 return 0;
1642
1643 sid = cred_sid(cred);
1644 isec = selinux_inode(inode);
1645
1646 return avc_has_perm(&selinux_state,
1647 sid, isec->sid, isec->sclass, perms, adp);
1648 }
1649
1650 /* Same as inode_has_perm, but pass explicit audit data containing
1651 the dentry to help the auditing code to more easily generate the
1652 pathname if needed. */
dentry_has_perm(const struct cred * cred,struct dentry * dentry,u32 av)1653 static inline int dentry_has_perm(const struct cred *cred,
1654 struct dentry *dentry,
1655 u32 av)
1656 {
1657 struct inode *inode = d_backing_inode(dentry);
1658 struct common_audit_data ad;
1659
1660 ad.type = LSM_AUDIT_DATA_DENTRY;
1661 ad.u.dentry = dentry;
1662 __inode_security_revalidate(inode, dentry, true);
1663 return inode_has_perm(cred, inode, av, &ad);
1664 }
1665
1666 /* Same as inode_has_perm, but pass explicit audit data containing
1667 the path to help the auditing code to more easily generate the
1668 pathname if needed. */
path_has_perm(const struct cred * cred,const struct path * path,u32 av)1669 static inline int path_has_perm(const struct cred *cred,
1670 const struct path *path,
1671 u32 av)
1672 {
1673 struct inode *inode = d_backing_inode(path->dentry);
1674 struct common_audit_data ad;
1675
1676 ad.type = LSM_AUDIT_DATA_PATH;
1677 ad.u.path = *path;
1678 __inode_security_revalidate(inode, path->dentry, true);
1679 return inode_has_perm(cred, inode, av, &ad);
1680 }
1681
1682 /* 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)1683 static inline int file_path_has_perm(const struct cred *cred,
1684 struct file *file,
1685 u32 av)
1686 {
1687 struct common_audit_data ad;
1688
1689 ad.type = LSM_AUDIT_DATA_FILE;
1690 ad.u.file = file;
1691 return inode_has_perm(cred, file_inode(file), av, &ad);
1692 }
1693
1694 #ifdef CONFIG_BPF_SYSCALL
1695 static int bpf_fd_pass(struct file *file, u32 sid);
1696 #endif
1697
1698 /* Check whether a task can use an open file descriptor to
1699 access an inode in a given way. Check access to the
1700 descriptor itself, and then use dentry_has_perm to
1701 check a particular permission to the file.
1702 Access to the descriptor is implicitly granted if it
1703 has the same SID as the process. If av is zero, then
1704 access to the file is not checked, e.g. for cases
1705 where only the descriptor is affected like seek. */
file_has_perm(const struct cred * cred,struct file * file,u32 av)1706 static int file_has_perm(const struct cred *cred,
1707 struct file *file,
1708 u32 av)
1709 {
1710 struct file_security_struct *fsec = selinux_file(file);
1711 struct inode *inode = file_inode(file);
1712 struct common_audit_data ad;
1713 u32 sid = cred_sid(cred);
1714 int rc;
1715
1716 ad.type = LSM_AUDIT_DATA_FILE;
1717 ad.u.file = file;
1718
1719 if (sid != fsec->sid) {
1720 rc = avc_has_perm(&selinux_state,
1721 sid, fsec->sid,
1722 SECCLASS_FD,
1723 FD__USE,
1724 &ad);
1725 if (rc)
1726 goto out;
1727 }
1728
1729 #ifdef CONFIG_BPF_SYSCALL
1730 rc = bpf_fd_pass(file, cred_sid(cred));
1731 if (rc)
1732 return rc;
1733 #endif
1734
1735 /* av is zero if only checking access to the descriptor. */
1736 rc = 0;
1737 if (av)
1738 rc = inode_has_perm(cred, inode, av, &ad);
1739
1740 out:
1741 return rc;
1742 }
1743
1744 /*
1745 * Determine the label for an inode that might be unioned.
1746 */
1747 static int
selinux_determine_inode_label(const struct task_security_struct * tsec,struct inode * dir,const struct qstr * name,u16 tclass,u32 * _new_isid)1748 selinux_determine_inode_label(const struct task_security_struct *tsec,
1749 struct inode *dir,
1750 const struct qstr *name, u16 tclass,
1751 u32 *_new_isid)
1752 {
1753 const struct superblock_security_struct *sbsec = dir->i_sb->s_security;
1754
1755 if ((sbsec->flags & SE_SBINITIALIZED) &&
1756 (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
1757 *_new_isid = sbsec->mntpoint_sid;
1758 } else if ((sbsec->flags & SBLABEL_MNT) &&
1759 tsec->create_sid) {
1760 *_new_isid = tsec->create_sid;
1761 } else {
1762 const struct inode_security_struct *dsec = inode_security(dir);
1763 return security_transition_sid(&selinux_state, tsec->sid,
1764 dsec->sid, tclass,
1765 name, _new_isid);
1766 }
1767
1768 return 0;
1769 }
1770
1771 /* Check whether a task can create a file. */
may_create(struct inode * dir,struct dentry * dentry,u16 tclass)1772 static int may_create(struct inode *dir,
1773 struct dentry *dentry,
1774 u16 tclass)
1775 {
1776 const struct task_security_struct *tsec = selinux_cred(current_cred());
1777 struct inode_security_struct *dsec;
1778 struct superblock_security_struct *sbsec;
1779 u32 sid, newsid;
1780 struct common_audit_data ad;
1781 int rc;
1782
1783 dsec = inode_security(dir);
1784 sbsec = dir->i_sb->s_security;
1785
1786 sid = tsec->sid;
1787
1788 ad.type = LSM_AUDIT_DATA_DENTRY;
1789 ad.u.dentry = dentry;
1790
1791 rc = avc_has_perm(&selinux_state,
1792 sid, dsec->sid, SECCLASS_DIR,
1793 DIR__ADD_NAME | DIR__SEARCH,
1794 &ad);
1795 if (rc)
1796 return rc;
1797
1798 rc = selinux_determine_inode_label(tsec, dir, &dentry->d_name, tclass,
1799 &newsid);
1800 if (rc)
1801 return rc;
1802
1803 rc = avc_has_perm(&selinux_state,
1804 sid, newsid, tclass, FILE__CREATE, &ad);
1805 if (rc)
1806 return rc;
1807
1808 return avc_has_perm(&selinux_state,
1809 newsid, sbsec->sid,
1810 SECCLASS_FILESYSTEM,
1811 FILESYSTEM__ASSOCIATE, &ad);
1812 }
1813
1814 #define MAY_LINK 0
1815 #define MAY_UNLINK 1
1816 #define MAY_RMDIR 2
1817
1818 /* Check whether a task can link, unlink, or rmdir a file/directory. */
may_link(struct inode * dir,struct dentry * dentry,int kind)1819 static int may_link(struct inode *dir,
1820 struct dentry *dentry,
1821 int kind)
1822
1823 {
1824 struct inode_security_struct *dsec, *isec;
1825 struct common_audit_data ad;
1826 u32 sid = current_sid();
1827 u32 av;
1828 int rc;
1829
1830 dsec = inode_security(dir);
1831 isec = backing_inode_security(dentry);
1832
1833 ad.type = LSM_AUDIT_DATA_DENTRY;
1834 ad.u.dentry = dentry;
1835
1836 av = DIR__SEARCH;
1837 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1838 rc = avc_has_perm(&selinux_state,
1839 sid, dsec->sid, SECCLASS_DIR, av, &ad);
1840 if (rc)
1841 return rc;
1842
1843 switch (kind) {
1844 case MAY_LINK:
1845 av = FILE__LINK;
1846 break;
1847 case MAY_UNLINK:
1848 av = FILE__UNLINK;
1849 break;
1850 case MAY_RMDIR:
1851 av = DIR__RMDIR;
1852 break;
1853 default:
1854 pr_warn("SELinux: %s: unrecognized kind %d\n",
1855 __func__, kind);
1856 return 0;
1857 }
1858
1859 rc = avc_has_perm(&selinux_state,
1860 sid, isec->sid, isec->sclass, av, &ad);
1861 return rc;
1862 }
1863
may_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry)1864 static inline int may_rename(struct inode *old_dir,
1865 struct dentry *old_dentry,
1866 struct inode *new_dir,
1867 struct dentry *new_dentry)
1868 {
1869 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1870 struct common_audit_data ad;
1871 u32 sid = current_sid();
1872 u32 av;
1873 int old_is_dir, new_is_dir;
1874 int rc;
1875
1876 old_dsec = inode_security(old_dir);
1877 old_isec = backing_inode_security(old_dentry);
1878 old_is_dir = d_is_dir(old_dentry);
1879 new_dsec = inode_security(new_dir);
1880
1881 ad.type = LSM_AUDIT_DATA_DENTRY;
1882
1883 ad.u.dentry = old_dentry;
1884 rc = avc_has_perm(&selinux_state,
1885 sid, old_dsec->sid, SECCLASS_DIR,
1886 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1887 if (rc)
1888 return rc;
1889 rc = avc_has_perm(&selinux_state,
1890 sid, old_isec->sid,
1891 old_isec->sclass, FILE__RENAME, &ad);
1892 if (rc)
1893 return rc;
1894 if (old_is_dir && new_dir != old_dir) {
1895 rc = avc_has_perm(&selinux_state,
1896 sid, old_isec->sid,
1897 old_isec->sclass, DIR__REPARENT, &ad);
1898 if (rc)
1899 return rc;
1900 }
1901
1902 ad.u.dentry = new_dentry;
1903 av = DIR__ADD_NAME | DIR__SEARCH;
1904 if (d_is_positive(new_dentry))
1905 av |= DIR__REMOVE_NAME;
1906 rc = avc_has_perm(&selinux_state,
1907 sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1908 if (rc)
1909 return rc;
1910 if (d_is_positive(new_dentry)) {
1911 new_isec = backing_inode_security(new_dentry);
1912 new_is_dir = d_is_dir(new_dentry);
1913 rc = avc_has_perm(&selinux_state,
1914 sid, new_isec->sid,
1915 new_isec->sclass,
1916 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1917 if (rc)
1918 return rc;
1919 }
1920
1921 return 0;
1922 }
1923
1924 /* Check whether a task can perform a filesystem operation. */
superblock_has_perm(const struct cred * cred,struct super_block * sb,u32 perms,struct common_audit_data * ad)1925 static int superblock_has_perm(const struct cred *cred,
1926 struct super_block *sb,
1927 u32 perms,
1928 struct common_audit_data *ad)
1929 {
1930 struct superblock_security_struct *sbsec;
1931 u32 sid = cred_sid(cred);
1932
1933 sbsec = sb->s_security;
1934 return avc_has_perm(&selinux_state,
1935 sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1936 }
1937
1938 /* Convert a Linux mode and permission mask to an access vector. */
file_mask_to_av(int mode,int mask)1939 static inline u32 file_mask_to_av(int mode, int mask)
1940 {
1941 u32 av = 0;
1942
1943 if (!S_ISDIR(mode)) {
1944 if (mask & MAY_EXEC)
1945 av |= FILE__EXECUTE;
1946 if (mask & MAY_READ)
1947 av |= FILE__READ;
1948
1949 if (mask & MAY_APPEND)
1950 av |= FILE__APPEND;
1951 else if (mask & MAY_WRITE)
1952 av |= FILE__WRITE;
1953
1954 } else {
1955 if (mask & MAY_EXEC)
1956 av |= DIR__SEARCH;
1957 if (mask & MAY_WRITE)
1958 av |= DIR__WRITE;
1959 if (mask & MAY_READ)
1960 av |= DIR__READ;
1961 }
1962
1963 return av;
1964 }
1965
1966 /* Convert a Linux file to an access vector. */
file_to_av(struct file * file)1967 static inline u32 file_to_av(struct file *file)
1968 {
1969 u32 av = 0;
1970
1971 if (file->f_mode & FMODE_READ)
1972 av |= FILE__READ;
1973 if (file->f_mode & FMODE_WRITE) {
1974 if (file->f_flags & O_APPEND)
1975 av |= FILE__APPEND;
1976 else
1977 av |= FILE__WRITE;
1978 }
1979 if (!av) {
1980 /*
1981 * Special file opened with flags 3 for ioctl-only use.
1982 */
1983 av = FILE__IOCTL;
1984 }
1985
1986 return av;
1987 }
1988
1989 /*
1990 * Convert a file to an access vector and include the correct
1991 * open permission.
1992 */
open_file_to_av(struct file * file)1993 static inline u32 open_file_to_av(struct file *file)
1994 {
1995 u32 av = file_to_av(file);
1996 struct inode *inode = file_inode(file);
1997
1998 if (selinux_policycap_openperm() &&
1999 inode->i_sb->s_magic != SOCKFS_MAGIC)
2000 av |= FILE__OPEN;
2001
2002 return av;
2003 }
2004
2005 /* Hook functions begin here. */
2006
selinux_binder_set_context_mgr(const struct cred * mgr)2007 static int selinux_binder_set_context_mgr(const struct cred *mgr)
2008 {
2009 return avc_has_perm(&selinux_state,
2010 current_sid(), cred_sid(mgr), SECCLASS_BINDER,
2011 BINDER__SET_CONTEXT_MGR, NULL);
2012 }
2013
selinux_binder_transaction(const struct cred * from,const struct cred * to)2014 static int selinux_binder_transaction(const struct cred *from,
2015 const struct cred *to)
2016 {
2017 u32 mysid = current_sid();
2018 u32 fromsid = cred_sid(from);
2019 u32 tosid = cred_sid(to);
2020 int rc;
2021
2022 if (mysid != fromsid) {
2023 rc = avc_has_perm(&selinux_state,
2024 mysid, fromsid, SECCLASS_BINDER,
2025 BINDER__IMPERSONATE, NULL);
2026 if (rc)
2027 return rc;
2028 }
2029
2030 return avc_has_perm(&selinux_state, fromsid, tosid,
2031 SECCLASS_BINDER, BINDER__CALL, NULL);
2032 }
2033
selinux_binder_transfer_binder(const struct cred * from,const struct cred * to)2034 static int selinux_binder_transfer_binder(const struct cred *from,
2035 const struct cred *to)
2036 {
2037 return avc_has_perm(&selinux_state,
2038 cred_sid(from), cred_sid(to),
2039 SECCLASS_BINDER, BINDER__TRANSFER,
2040 NULL);
2041 }
2042
selinux_binder_transfer_file(const struct cred * from,const struct cred * to,struct file * file)2043 static int selinux_binder_transfer_file(const struct cred *from,
2044 const struct cred *to,
2045 struct file *file)
2046 {
2047 u32 sid = cred_sid(to);
2048 struct file_security_struct *fsec = selinux_file(file);
2049 struct dentry *dentry = file->f_path.dentry;
2050 struct inode_security_struct *isec;
2051 struct common_audit_data ad;
2052 int rc;
2053
2054 ad.type = LSM_AUDIT_DATA_PATH;
2055 ad.u.path = file->f_path;
2056
2057 if (sid != fsec->sid) {
2058 rc = avc_has_perm(&selinux_state,
2059 sid, fsec->sid,
2060 SECCLASS_FD,
2061 FD__USE,
2062 &ad);
2063 if (rc)
2064 return rc;
2065 }
2066
2067 #ifdef CONFIG_BPF_SYSCALL
2068 rc = bpf_fd_pass(file, sid);
2069 if (rc)
2070 return rc;
2071 #endif
2072
2073 if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
2074 return 0;
2075
2076 isec = backing_inode_security(dentry);
2077 return avc_has_perm(&selinux_state,
2078 sid, isec->sid, isec->sclass, file_to_av(file),
2079 &ad);
2080 }
2081
selinux_ptrace_access_check(struct task_struct * child,unsigned int mode)2082 static int selinux_ptrace_access_check(struct task_struct *child,
2083 unsigned int mode)
2084 {
2085 u32 sid = current_sid();
2086 u32 csid = task_sid(child);
2087
2088 if (mode & PTRACE_MODE_READ)
2089 return avc_has_perm(&selinux_state,
2090 sid, csid, SECCLASS_FILE, FILE__READ, NULL);
2091
2092 return avc_has_perm(&selinux_state,
2093 sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE, NULL);
2094 }
2095
selinux_ptrace_traceme(struct task_struct * parent)2096 static int selinux_ptrace_traceme(struct task_struct *parent)
2097 {
2098 return avc_has_perm(&selinux_state,
2099 task_sid(parent), current_sid(), SECCLASS_PROCESS,
2100 PROCESS__PTRACE, NULL);
2101 }
2102
selinux_capget(struct task_struct * target,kernel_cap_t * effective,kernel_cap_t * inheritable,kernel_cap_t * permitted)2103 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
2104 kernel_cap_t *inheritable, kernel_cap_t *permitted)
2105 {
2106 return avc_has_perm(&selinux_state,
2107 current_sid(), task_sid(target), SECCLASS_PROCESS,
2108 PROCESS__GETCAP, NULL);
2109 }
2110
selinux_capset(struct cred * new,const struct cred * old,const kernel_cap_t * effective,const kernel_cap_t * inheritable,const kernel_cap_t * permitted)2111 static int selinux_capset(struct cred *new, const struct cred *old,
2112 const kernel_cap_t *effective,
2113 const kernel_cap_t *inheritable,
2114 const kernel_cap_t *permitted)
2115 {
2116 return avc_has_perm(&selinux_state,
2117 cred_sid(old), cred_sid(new), SECCLASS_PROCESS,
2118 PROCESS__SETCAP, NULL);
2119 }
2120
2121 /*
2122 * (This comment used to live with the selinux_task_setuid hook,
2123 * which was removed).
2124 *
2125 * Since setuid only affects the current process, and since the SELinux
2126 * controls are not based on the Linux identity attributes, SELinux does not
2127 * need to control this operation. However, SELinux does control the use of
2128 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
2129 */
2130
selinux_capable(const struct cred * cred,struct user_namespace * ns,int cap,unsigned int opts)2131 static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
2132 int cap, unsigned int opts)
2133 {
2134 return cred_has_capability(cred, cap, opts, ns == &init_user_ns);
2135 }
2136
selinux_quotactl(int cmds,int type,int id,struct super_block * sb)2137 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
2138 {
2139 const struct cred *cred = current_cred();
2140 int rc = 0;
2141
2142 if (!sb)
2143 return 0;
2144
2145 switch (cmds) {
2146 case Q_SYNC:
2147 case Q_QUOTAON:
2148 case Q_QUOTAOFF:
2149 case Q_SETINFO:
2150 case Q_SETQUOTA:
2151 case Q_XQUOTAOFF:
2152 case Q_XQUOTAON:
2153 case Q_XSETQLIM:
2154 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
2155 break;
2156 case Q_GETFMT:
2157 case Q_GETINFO:
2158 case Q_GETQUOTA:
2159 case Q_XGETQUOTA:
2160 case Q_XGETQSTAT:
2161 case Q_XGETQSTATV:
2162 case Q_XGETNEXTQUOTA:
2163 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
2164 break;
2165 default:
2166 rc = 0; /* let the kernel handle invalid cmds */
2167 break;
2168 }
2169 return rc;
2170 }
2171
selinux_quota_on(struct dentry * dentry)2172 static int selinux_quota_on(struct dentry *dentry)
2173 {
2174 const struct cred *cred = current_cred();
2175
2176 return dentry_has_perm(cred, dentry, FILE__QUOTAON);
2177 }
2178
selinux_syslog(int type)2179 static int selinux_syslog(int type)
2180 {
2181 switch (type) {
2182 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */
2183 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */
2184 return avc_has_perm(&selinux_state,
2185 current_sid(), SECINITSID_KERNEL,
2186 SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL);
2187 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */
2188 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */
2189 /* Set level of messages printed to console */
2190 case SYSLOG_ACTION_CONSOLE_LEVEL:
2191 return avc_has_perm(&selinux_state,
2192 current_sid(), SECINITSID_KERNEL,
2193 SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE,
2194 NULL);
2195 }
2196 /* All other syslog types */
2197 return avc_has_perm(&selinux_state,
2198 current_sid(), SECINITSID_KERNEL,
2199 SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL);
2200 }
2201
2202 /*
2203 * Check that a process has enough memory to allocate a new virtual
2204 * mapping. 0 means there is enough memory for the allocation to
2205 * succeed and -ENOMEM implies there is not.
2206 *
2207 * Do not audit the selinux permission check, as this is applied to all
2208 * processes that allocate mappings.
2209 */
selinux_vm_enough_memory(struct mm_struct * mm,long pages)2210 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
2211 {
2212 int rc, cap_sys_admin = 0;
2213
2214 rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN,
2215 CAP_OPT_NOAUDIT, true);
2216 if (rc == 0)
2217 cap_sys_admin = 1;
2218
2219 return cap_sys_admin;
2220 }
2221
2222 /* binprm security operations */
2223
ptrace_parent_sid(void)2224 static u32 ptrace_parent_sid(void)
2225 {
2226 u32 sid = 0;
2227 struct task_struct *tracer;
2228
2229 rcu_read_lock();
2230 tracer = ptrace_parent(current);
2231 if (tracer)
2232 sid = task_sid(tracer);
2233 rcu_read_unlock();
2234
2235 return sid;
2236 }
2237
check_nnp_nosuid(const struct linux_binprm * bprm,const struct task_security_struct * old_tsec,const struct task_security_struct * new_tsec)2238 static int check_nnp_nosuid(const struct linux_binprm *bprm,
2239 const struct task_security_struct *old_tsec,
2240 const struct task_security_struct *new_tsec)
2241 {
2242 int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
2243 int nosuid = !mnt_may_suid(bprm->file->f_path.mnt);
2244 int rc;
2245 u32 av;
2246
2247 if (!nnp && !nosuid)
2248 return 0; /* neither NNP nor nosuid */
2249
2250 if (new_tsec->sid == old_tsec->sid)
2251 return 0; /* No change in credentials */
2252
2253 /*
2254 * If the policy enables the nnp_nosuid_transition policy capability,
2255 * then we permit transitions under NNP or nosuid if the
2256 * policy allows the corresponding permission between
2257 * the old and new contexts.
2258 */
2259 if (selinux_policycap_nnp_nosuid_transition()) {
2260 av = 0;
2261 if (nnp)
2262 av |= PROCESS2__NNP_TRANSITION;
2263 if (nosuid)
2264 av |= PROCESS2__NOSUID_TRANSITION;
2265 rc = avc_has_perm(&selinux_state,
2266 old_tsec->sid, new_tsec->sid,
2267 SECCLASS_PROCESS2, av, NULL);
2268 if (!rc)
2269 return 0;
2270 }
2271
2272 /*
2273 * We also permit NNP or nosuid transitions to bounded SIDs,
2274 * i.e. SIDs that are guaranteed to only be allowed a subset
2275 * of the permissions of the current SID.
2276 */
2277 rc = security_bounded_transition(&selinux_state, old_tsec->sid,
2278 new_tsec->sid);
2279 if (!rc)
2280 return 0;
2281
2282 /*
2283 * On failure, preserve the errno values for NNP vs nosuid.
2284 * NNP: Operation not permitted for caller.
2285 * nosuid: Permission denied to file.
2286 */
2287 if (nnp)
2288 return -EPERM;
2289 return -EACCES;
2290 }
2291
selinux_bprm_creds_for_exec(struct linux_binprm * bprm)2292 static int selinux_bprm_creds_for_exec(struct linux_binprm *bprm)
2293 {
2294 const struct task_security_struct *old_tsec;
2295 struct task_security_struct *new_tsec;
2296 struct inode_security_struct *isec;
2297 struct common_audit_data ad;
2298 struct inode *inode = file_inode(bprm->file);
2299 int rc;
2300
2301 /* SELinux context only depends on initial program or script and not
2302 * the script interpreter */
2303
2304 old_tsec = selinux_cred(current_cred());
2305 new_tsec = selinux_cred(bprm->cred);
2306 isec = inode_security(inode);
2307
2308 /* Default to the current task SID. */
2309 new_tsec->sid = old_tsec->sid;
2310 new_tsec->osid = old_tsec->sid;
2311
2312 /* Reset fs, key, and sock SIDs on execve. */
2313 new_tsec->create_sid = 0;
2314 new_tsec->keycreate_sid = 0;
2315 new_tsec->sockcreate_sid = 0;
2316
2317 if (old_tsec->exec_sid) {
2318 new_tsec->sid = old_tsec->exec_sid;
2319 /* Reset exec SID on execve. */
2320 new_tsec->exec_sid = 0;
2321
2322 /* Fail on NNP or nosuid if not an allowed transition. */
2323 rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2324 if (rc)
2325 return rc;
2326 } else {
2327 /* Check for a default transition on this program. */
2328 rc = security_transition_sid(&selinux_state, old_tsec->sid,
2329 isec->sid, SECCLASS_PROCESS, NULL,
2330 &new_tsec->sid);
2331 if (rc)
2332 return rc;
2333
2334 /*
2335 * Fallback to old SID on NNP or nosuid if not an allowed
2336 * transition.
2337 */
2338 rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2339 if (rc)
2340 new_tsec->sid = old_tsec->sid;
2341 }
2342
2343 ad.type = LSM_AUDIT_DATA_FILE;
2344 ad.u.file = bprm->file;
2345
2346 if (new_tsec->sid == old_tsec->sid) {
2347 rc = avc_has_perm(&selinux_state,
2348 old_tsec->sid, isec->sid,
2349 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2350 if (rc)
2351 return rc;
2352 } else {
2353 /* Check permissions for the transition. */
2354 rc = avc_has_perm(&selinux_state,
2355 old_tsec->sid, new_tsec->sid,
2356 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2357 if (rc)
2358 return rc;
2359
2360 rc = avc_has_perm(&selinux_state,
2361 new_tsec->sid, isec->sid,
2362 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2363 if (rc)
2364 return rc;
2365
2366 /* Check for shared state */
2367 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2368 rc = avc_has_perm(&selinux_state,
2369 old_tsec->sid, new_tsec->sid,
2370 SECCLASS_PROCESS, PROCESS__SHARE,
2371 NULL);
2372 if (rc)
2373 return -EPERM;
2374 }
2375
2376 /* Make sure that anyone attempting to ptrace over a task that
2377 * changes its SID has the appropriate permit */
2378 if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
2379 u32 ptsid = ptrace_parent_sid();
2380 if (ptsid != 0) {
2381 rc = avc_has_perm(&selinux_state,
2382 ptsid, new_tsec->sid,
2383 SECCLASS_PROCESS,
2384 PROCESS__PTRACE, NULL);
2385 if (rc)
2386 return -EPERM;
2387 }
2388 }
2389
2390 /* Clear any possibly unsafe personality bits on exec: */
2391 bprm->per_clear |= PER_CLEAR_ON_SETID;
2392
2393 /* Enable secure mode for SIDs transitions unless
2394 the noatsecure permission is granted between
2395 the two SIDs, i.e. ahp returns 0. */
2396 rc = avc_has_perm(&selinux_state,
2397 old_tsec->sid, new_tsec->sid,
2398 SECCLASS_PROCESS, PROCESS__NOATSECURE,
2399 NULL);
2400 bprm->secureexec |= !!rc;
2401 }
2402
2403 return 0;
2404 }
2405
match_file(const void * p,struct file * file,unsigned fd)2406 static int match_file(const void *p, struct file *file, unsigned fd)
2407 {
2408 return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0;
2409 }
2410
2411 /* Derived from fs/exec.c:flush_old_files. */
flush_unauthorized_files(const struct cred * cred,struct files_struct * files)2412 static inline void flush_unauthorized_files(const struct cred *cred,
2413 struct files_struct *files)
2414 {
2415 struct file *file, *devnull = NULL;
2416 struct tty_struct *tty;
2417 int drop_tty = 0;
2418 unsigned n;
2419
2420 tty = get_current_tty();
2421 if (tty) {
2422 spin_lock(&tty->files_lock);
2423 if (!list_empty(&tty->tty_files)) {
2424 struct tty_file_private *file_priv;
2425
2426 /* Revalidate access to controlling tty.
2427 Use file_path_has_perm on the tty path directly
2428 rather than using file_has_perm, as this particular
2429 open file may belong to another process and we are
2430 only interested in the inode-based check here. */
2431 file_priv = list_first_entry(&tty->tty_files,
2432 struct tty_file_private, list);
2433 file = file_priv->file;
2434 if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
2435 drop_tty = 1;
2436 }
2437 spin_unlock(&tty->files_lock);
2438 tty_kref_put(tty);
2439 }
2440 /* Reset controlling tty. */
2441 if (drop_tty)
2442 no_tty();
2443
2444 /* Revalidate access to inherited open files. */
2445 n = iterate_fd(files, 0, match_file, cred);
2446 if (!n) /* none found? */
2447 return;
2448
2449 devnull = dentry_open(&selinux_null, O_RDWR, cred);
2450 if (IS_ERR(devnull))
2451 devnull = NULL;
2452 /* replace all the matching ones with this */
2453 do {
2454 replace_fd(n - 1, devnull, 0);
2455 } while ((n = iterate_fd(files, n, match_file, cred)) != 0);
2456 if (devnull)
2457 fput(devnull);
2458 }
2459
2460 /*
2461 * Prepare a process for imminent new credential changes due to exec
2462 */
selinux_bprm_committing_creds(struct linux_binprm * bprm)2463 static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
2464 {
2465 struct task_security_struct *new_tsec;
2466 struct rlimit *rlim, *initrlim;
2467 int rc, i;
2468
2469 new_tsec = selinux_cred(bprm->cred);
2470 if (new_tsec->sid == new_tsec->osid)
2471 return;
2472
2473 /* Close files for which the new task SID is not authorized. */
2474 flush_unauthorized_files(bprm->cred, current->files);
2475
2476 /* Always clear parent death signal on SID transitions. */
2477 current->pdeath_signal = 0;
2478
2479 /* Check whether the new SID can inherit resource limits from the old
2480 * SID. If not, reset all soft limits to the lower of the current
2481 * task's hard limit and the init task's soft limit.
2482 *
2483 * Note that the setting of hard limits (even to lower them) can be
2484 * controlled by the setrlimit check. The inclusion of the init task's
2485 * soft limit into the computation is to avoid resetting soft limits
2486 * higher than the default soft limit for cases where the default is
2487 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2488 */
2489 rc = avc_has_perm(&selinux_state,
2490 new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2491 PROCESS__RLIMITINH, NULL);
2492 if (rc) {
2493 /* protect against do_prlimit() */
2494 task_lock(current);
2495 for (i = 0; i < RLIM_NLIMITS; i++) {
2496 rlim = current->signal->rlim + i;
2497 initrlim = init_task.signal->rlim + i;
2498 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2499 }
2500 task_unlock(current);
2501 if (IS_ENABLED(CONFIG_POSIX_TIMERS))
2502 update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
2503 }
2504 }
2505
2506 /*
2507 * Clean up the process immediately after the installation of new credentials
2508 * due to exec
2509 */
selinux_bprm_committed_creds(struct linux_binprm * bprm)2510 static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
2511 {
2512 const struct task_security_struct *tsec = selinux_cred(current_cred());
2513 u32 osid, sid;
2514 int rc;
2515
2516 osid = tsec->osid;
2517 sid = tsec->sid;
2518
2519 if (sid == osid)
2520 return;
2521
2522 /* Check whether the new SID can inherit signal state from the old SID.
2523 * If not, clear itimers to avoid subsequent signal generation and
2524 * flush and unblock signals.
2525 *
2526 * This must occur _after_ the task SID has been updated so that any
2527 * kill done after the flush will be checked against the new SID.
2528 */
2529 rc = avc_has_perm(&selinux_state,
2530 osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2531 if (rc) {
2532 clear_itimer();
2533
2534 spin_lock_irq(¤t->sighand->siglock);
2535 if (!fatal_signal_pending(current)) {
2536 flush_sigqueue(¤t->pending);
2537 flush_sigqueue(¤t->signal->shared_pending);
2538 flush_signal_handlers(current, 1);
2539 sigemptyset(¤t->blocked);
2540 recalc_sigpending();
2541 }
2542 spin_unlock_irq(¤t->sighand->siglock);
2543 }
2544
2545 /* Wake up the parent if it is waiting so that it can recheck
2546 * wait permission to the new task SID. */
2547 read_lock(&tasklist_lock);
2548 __wake_up_parent(current, current->real_parent);
2549 read_unlock(&tasklist_lock);
2550 }
2551
2552 /* superblock security operations */
2553
selinux_sb_alloc_security(struct super_block * sb)2554 static int selinux_sb_alloc_security(struct super_block *sb)
2555 {
2556 struct superblock_security_struct *sbsec;
2557
2558 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
2559 if (!sbsec)
2560 return -ENOMEM;
2561
2562 mutex_init(&sbsec->lock);
2563 INIT_LIST_HEAD(&sbsec->isec_head);
2564 spin_lock_init(&sbsec->isec_lock);
2565 sbsec->sb = sb;
2566 sbsec->sid = SECINITSID_UNLABELED;
2567 sbsec->def_sid = SECINITSID_FILE;
2568 sbsec->mntpoint_sid = SECINITSID_UNLABELED;
2569 sb->s_security = sbsec;
2570
2571 return 0;
2572 }
2573
selinux_sb_free_security(struct super_block * sb)2574 static void selinux_sb_free_security(struct super_block *sb)
2575 {
2576 superblock_free_security(sb);
2577 }
2578
opt_len(const char * s)2579 static inline int opt_len(const char *s)
2580 {
2581 bool open_quote = false;
2582 int len;
2583 char c;
2584
2585 for (len = 0; (c = s[len]) != '\0'; len++) {
2586 if (c == '"')
2587 open_quote = !open_quote;
2588 if (c == ',' && !open_quote)
2589 break;
2590 }
2591 return len;
2592 }
2593
selinux_sb_eat_lsm_opts(char * options,void ** mnt_opts)2594 static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
2595 {
2596 char *from = options;
2597 char *to = options;
2598 bool first = true;
2599 int rc;
2600
2601 while (1) {
2602 int len = opt_len(from);
2603 int token;
2604 char *arg = NULL;
2605
2606 token = match_opt_prefix(from, len, &arg);
2607
2608 if (token != Opt_error) {
2609 char *p, *q;
2610
2611 /* strip quotes */
2612 if (arg) {
2613 for (p = q = arg; p < from + len; p++) {
2614 char c = *p;
2615 if (c != '"')
2616 *q++ = c;
2617 }
2618 arg = kmemdup_nul(arg, q - arg, GFP_KERNEL);
2619 if (!arg) {
2620 rc = -ENOMEM;
2621 goto free_opt;
2622 }
2623 }
2624 rc = selinux_add_opt(token, arg, mnt_opts);
2625 if (unlikely(rc)) {
2626 kfree(arg);
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_remount(struct super_block * sb,void * mnt_opts)2654 static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
2655 {
2656 struct selinux_mnt_opts *opts = mnt_opts;
2657 struct superblock_security_struct *sbsec = sb->s_security;
2658 u32 sid;
2659 int rc;
2660
2661 if (!(sbsec->flags & SE_SBINITIALIZED))
2662 return 0;
2663
2664 if (!opts)
2665 return 0;
2666
2667 if (opts->fscontext) {
2668 rc = parse_sid(sb, opts->fscontext, &sid);
2669 if (rc)
2670 return rc;
2671 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
2672 goto out_bad_option;
2673 }
2674 if (opts->context) {
2675 rc = parse_sid(sb, opts->context, &sid);
2676 if (rc)
2677 return rc;
2678 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
2679 goto out_bad_option;
2680 }
2681 if (opts->rootcontext) {
2682 struct inode_security_struct *root_isec;
2683 root_isec = backing_inode_security(sb->s_root);
2684 rc = parse_sid(sb, opts->rootcontext, &sid);
2685 if (rc)
2686 return rc;
2687 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
2688 goto out_bad_option;
2689 }
2690 if (opts->defcontext) {
2691 rc = parse_sid(sb, opts->defcontext, &sid);
2692 if (rc)
2693 return rc;
2694 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
2695 goto out_bad_option;
2696 }
2697 return 0;
2698
2699 out_bad_option:
2700 pr_warn("SELinux: unable to change security options "
2701 "during remount (dev %s, type=%s)\n", sb->s_id,
2702 sb->s_type->name);
2703 return -EINVAL;
2704 }
2705
selinux_sb_kern_mount(struct super_block * sb)2706 static int selinux_sb_kern_mount(struct super_block *sb)
2707 {
2708 const struct cred *cred = current_cred();
2709 struct common_audit_data ad;
2710
2711 ad.type = LSM_AUDIT_DATA_DENTRY;
2712 ad.u.dentry = sb->s_root;
2713 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2714 }
2715
selinux_sb_statfs(struct dentry * dentry)2716 static int selinux_sb_statfs(struct dentry *dentry)
2717 {
2718 const struct cred *cred = current_cred();
2719 struct common_audit_data ad;
2720
2721 ad.type = LSM_AUDIT_DATA_DENTRY;
2722 ad.u.dentry = dentry->d_sb->s_root;
2723 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2724 }
2725
selinux_mount(const char * dev_name,const struct path * path,const char * type,unsigned long flags,void * data)2726 static int selinux_mount(const char *dev_name,
2727 const struct path *path,
2728 const char *type,
2729 unsigned long flags,
2730 void *data)
2731 {
2732 const struct cred *cred = current_cred();
2733
2734 if (flags & MS_REMOUNT)
2735 return superblock_has_perm(cred, path->dentry->d_sb,
2736 FILESYSTEM__REMOUNT, NULL);
2737 else
2738 return path_has_perm(cred, path, FILE__MOUNTON);
2739 }
2740
selinux_move_mount(const struct path * from_path,const struct path * to_path)2741 static int selinux_move_mount(const struct path *from_path,
2742 const struct path *to_path)
2743 {
2744 const struct cred *cred = current_cred();
2745
2746 return path_has_perm(cred, to_path, FILE__MOUNTON);
2747 }
2748
selinux_umount(struct vfsmount * mnt,int flags)2749 static int selinux_umount(struct vfsmount *mnt, int flags)
2750 {
2751 const struct cred *cred = current_cred();
2752
2753 return superblock_has_perm(cred, mnt->mnt_sb,
2754 FILESYSTEM__UNMOUNT, NULL);
2755 }
2756
selinux_fs_context_dup(struct fs_context * fc,struct fs_context * src_fc)2757 static int selinux_fs_context_dup(struct fs_context *fc,
2758 struct fs_context *src_fc)
2759 {
2760 const struct selinux_mnt_opts *src = src_fc->security;
2761 struct selinux_mnt_opts *opts;
2762
2763 if (!src)
2764 return 0;
2765
2766 fc->security = kzalloc(sizeof(struct selinux_mnt_opts), GFP_KERNEL);
2767 if (!fc->security)
2768 return -ENOMEM;
2769
2770 opts = fc->security;
2771
2772 if (src->fscontext) {
2773 opts->fscontext = kstrdup(src->fscontext, GFP_KERNEL);
2774 if (!opts->fscontext)
2775 return -ENOMEM;
2776 }
2777 if (src->context) {
2778 opts->context = kstrdup(src->context, GFP_KERNEL);
2779 if (!opts->context)
2780 return -ENOMEM;
2781 }
2782 if (src->rootcontext) {
2783 opts->rootcontext = kstrdup(src->rootcontext, GFP_KERNEL);
2784 if (!opts->rootcontext)
2785 return -ENOMEM;
2786 }
2787 if (src->defcontext) {
2788 opts->defcontext = kstrdup(src->defcontext, GFP_KERNEL);
2789 if (!opts->defcontext)
2790 return -ENOMEM;
2791 }
2792 return 0;
2793 }
2794
2795 static const struct fs_parameter_spec selinux_fs_parameters[] = {
2796 fsparam_string(CONTEXT_STR, Opt_context),
2797 fsparam_string(DEFCONTEXT_STR, Opt_defcontext),
2798 fsparam_string(FSCONTEXT_STR, Opt_fscontext),
2799 fsparam_string(ROOTCONTEXT_STR, Opt_rootcontext),
2800 fsparam_flag (SECLABEL_STR, Opt_seclabel),
2801 {}
2802 };
2803
selinux_fs_context_parse_param(struct fs_context * fc,struct fs_parameter * param)2804 static int selinux_fs_context_parse_param(struct fs_context *fc,
2805 struct fs_parameter *param)
2806 {
2807 struct fs_parse_result result;
2808 int opt, rc;
2809
2810 opt = fs_parse(fc, selinux_fs_parameters, param, &result);
2811 if (opt < 0)
2812 return opt;
2813
2814 rc = selinux_add_opt(opt, param->string, &fc->security);
2815 if (!rc) {
2816 param->string = NULL;
2817 rc = 1;
2818 }
2819 return rc;
2820 }
2821
2822 /* inode security operations */
2823
selinux_inode_alloc_security(struct inode * inode)2824 static int selinux_inode_alloc_security(struct inode *inode)
2825 {
2826 struct inode_security_struct *isec = selinux_inode(inode);
2827 u32 sid = current_sid();
2828
2829 spin_lock_init(&isec->lock);
2830 INIT_LIST_HEAD(&isec->list);
2831 isec->inode = inode;
2832 isec->sid = SECINITSID_UNLABELED;
2833 isec->sclass = SECCLASS_FILE;
2834 isec->task_sid = sid;
2835 isec->initialized = LABEL_INVALID;
2836
2837 return 0;
2838 }
2839
selinux_inode_free_security(struct inode * inode)2840 static void selinux_inode_free_security(struct inode *inode)
2841 {
2842 inode_free_security(inode);
2843 }
2844
selinux_dentry_init_security(struct dentry * dentry,int mode,const struct qstr * name,void ** ctx,u32 * ctxlen)2845 static int selinux_dentry_init_security(struct dentry *dentry, int mode,
2846 const struct qstr *name, void **ctx,
2847 u32 *ctxlen)
2848 {
2849 u32 newsid;
2850 int rc;
2851
2852 rc = selinux_determine_inode_label(selinux_cred(current_cred()),
2853 d_inode(dentry->d_parent), name,
2854 inode_mode_to_security_class(mode),
2855 &newsid);
2856 if (rc)
2857 return rc;
2858
2859 return security_sid_to_context(&selinux_state, newsid, (char **)ctx,
2860 ctxlen);
2861 }
2862
selinux_dentry_create_files_as(struct dentry * dentry,int mode,struct qstr * name,const struct cred * old,struct cred * new)2863 static int selinux_dentry_create_files_as(struct dentry *dentry, int mode,
2864 struct qstr *name,
2865 const struct cred *old,
2866 struct cred *new)
2867 {
2868 u32 newsid;
2869 int rc;
2870 struct task_security_struct *tsec;
2871
2872 rc = selinux_determine_inode_label(selinux_cred(old),
2873 d_inode(dentry->d_parent), name,
2874 inode_mode_to_security_class(mode),
2875 &newsid);
2876 if (rc)
2877 return rc;
2878
2879 tsec = selinux_cred(new);
2880 tsec->create_sid = newsid;
2881 return 0;
2882 }
2883
selinux_inode_init_security(struct inode * inode,struct inode * dir,const struct qstr * qstr,const char ** name,void ** value,size_t * len)2884 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2885 const struct qstr *qstr,
2886 const char **name,
2887 void **value, size_t *len)
2888 {
2889 const struct task_security_struct *tsec = selinux_cred(current_cred());
2890 struct superblock_security_struct *sbsec;
2891 u32 newsid, clen;
2892 int rc;
2893 char *context;
2894
2895 sbsec = dir->i_sb->s_security;
2896
2897 newsid = tsec->create_sid;
2898
2899 rc = selinux_determine_inode_label(tsec, dir, qstr,
2900 inode_mode_to_security_class(inode->i_mode),
2901 &newsid);
2902 if (rc)
2903 return rc;
2904
2905 /* Possibly defer initialization to selinux_complete_init. */
2906 if (sbsec->flags & SE_SBINITIALIZED) {
2907 struct inode_security_struct *isec = selinux_inode(inode);
2908 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2909 isec->sid = newsid;
2910 isec->initialized = LABEL_INITIALIZED;
2911 }
2912
2913 if (!selinux_initialized(&selinux_state) ||
2914 !(sbsec->flags & SBLABEL_MNT))
2915 return -EOPNOTSUPP;
2916
2917 if (name)
2918 *name = XATTR_SELINUX_SUFFIX;
2919
2920 if (value && len) {
2921 rc = security_sid_to_context_force(&selinux_state, newsid,
2922 &context, &clen);
2923 if (rc)
2924 return rc;
2925 *value = context;
2926 *len = clen;
2927 }
2928
2929 return 0;
2930 }
2931
selinux_inode_create(struct inode * dir,struct dentry * dentry,umode_t mode)2932 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
2933 {
2934 return may_create(dir, dentry, SECCLASS_FILE);
2935 }
2936
selinux_inode_link(struct dentry * old_dentry,struct inode * dir,struct dentry * new_dentry)2937 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2938 {
2939 return may_link(dir, old_dentry, MAY_LINK);
2940 }
2941
selinux_inode_unlink(struct inode * dir,struct dentry * dentry)2942 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2943 {
2944 return may_link(dir, dentry, MAY_UNLINK);
2945 }
2946
selinux_inode_symlink(struct inode * dir,struct dentry * dentry,const char * name)2947 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2948 {
2949 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2950 }
2951
selinux_inode_mkdir(struct inode * dir,struct dentry * dentry,umode_t mask)2952 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
2953 {
2954 return may_create(dir, dentry, SECCLASS_DIR);
2955 }
2956
selinux_inode_rmdir(struct inode * dir,struct dentry * dentry)2957 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2958 {
2959 return may_link(dir, dentry, MAY_RMDIR);
2960 }
2961
selinux_inode_mknod(struct inode * dir,struct dentry * dentry,umode_t mode,dev_t dev)2962 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
2963 {
2964 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2965 }
2966
selinux_inode_rename(struct inode * old_inode,struct dentry * old_dentry,struct inode * new_inode,struct dentry * new_dentry)2967 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2968 struct inode *new_inode, struct dentry *new_dentry)
2969 {
2970 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2971 }
2972
selinux_inode_readlink(struct dentry * dentry)2973 static int selinux_inode_readlink(struct dentry *dentry)
2974 {
2975 const struct cred *cred = current_cred();
2976
2977 return dentry_has_perm(cred, dentry, FILE__READ);
2978 }
2979
selinux_inode_follow_link(struct dentry * dentry,struct inode * inode,bool rcu)2980 static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
2981 bool rcu)
2982 {
2983 const struct cred *cred = current_cred();
2984 struct common_audit_data ad;
2985 struct inode_security_struct *isec;
2986 u32 sid;
2987
2988 validate_creds(cred);
2989
2990 ad.type = LSM_AUDIT_DATA_DENTRY;
2991 ad.u.dentry = dentry;
2992 sid = cred_sid(cred);
2993 isec = inode_security_rcu(inode, rcu);
2994 if (IS_ERR(isec))
2995 return PTR_ERR(isec);
2996
2997 return avc_has_perm_flags(&selinux_state,
2998 sid, isec->sid, isec->sclass, FILE__READ, &ad,
2999 rcu ? MAY_NOT_BLOCK : 0);
3000 }
3001
audit_inode_permission(struct inode * inode,u32 perms,u32 audited,u32 denied,int result)3002 static noinline int audit_inode_permission(struct inode *inode,
3003 u32 perms, u32 audited, u32 denied,
3004 int result)
3005 {
3006 struct common_audit_data ad;
3007 struct inode_security_struct *isec = selinux_inode(inode);
3008 int rc;
3009
3010 ad.type = LSM_AUDIT_DATA_INODE;
3011 ad.u.inode = inode;
3012
3013 rc = slow_avc_audit(&selinux_state,
3014 current_sid(), isec->sid, isec->sclass, perms,
3015 audited, denied, result, &ad);
3016 if (rc)
3017 return rc;
3018 return 0;
3019 }
3020
selinux_inode_permission(struct inode * inode,int mask)3021 static int selinux_inode_permission(struct inode *inode, int mask)
3022 {
3023 const struct cred *cred = current_cred();
3024 u32 perms;
3025 bool from_access;
3026 bool no_block = mask & MAY_NOT_BLOCK;
3027 struct inode_security_struct *isec;
3028 u32 sid;
3029 struct av_decision avd;
3030 int rc, rc2;
3031 u32 audited, denied;
3032
3033 from_access = mask & MAY_ACCESS;
3034 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
3035
3036 /* No permission to check. Existence test. */
3037 if (!mask)
3038 return 0;
3039
3040 validate_creds(cred);
3041
3042 if (unlikely(IS_PRIVATE(inode)))
3043 return 0;
3044
3045 perms = file_mask_to_av(inode->i_mode, mask);
3046
3047 sid = cred_sid(cred);
3048 isec = inode_security_rcu(inode, no_block);
3049 if (IS_ERR(isec))
3050 return PTR_ERR(isec);
3051
3052 rc = avc_has_perm_noaudit(&selinux_state,
3053 sid, isec->sid, isec->sclass, perms,
3054 no_block ? AVC_NONBLOCKING : 0,
3055 &avd);
3056 audited = avc_audit_required(perms, &avd, rc,
3057 from_access ? FILE__AUDIT_ACCESS : 0,
3058 &denied);
3059 if (likely(!audited))
3060 return rc;
3061
3062 /* fall back to ref-walk if we have to generate audit */
3063 if (no_block)
3064 return -ECHILD;
3065
3066 rc2 = audit_inode_permission(inode, perms, audited, denied, rc);
3067 if (rc2)
3068 return rc2;
3069 return rc;
3070 }
3071
selinux_inode_setattr(struct dentry * dentry,struct iattr * iattr)3072 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
3073 {
3074 const struct cred *cred = current_cred();
3075 struct inode *inode = d_backing_inode(dentry);
3076 unsigned int ia_valid = iattr->ia_valid;
3077 __u32 av = FILE__WRITE;
3078
3079 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
3080 if (ia_valid & ATTR_FORCE) {
3081 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
3082 ATTR_FORCE);
3083 if (!ia_valid)
3084 return 0;
3085 }
3086
3087 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
3088 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
3089 return dentry_has_perm(cred, dentry, FILE__SETATTR);
3090
3091 if (selinux_policycap_openperm() &&
3092 inode->i_sb->s_magic != SOCKFS_MAGIC &&
3093 (ia_valid & ATTR_SIZE) &&
3094 !(ia_valid & ATTR_FILE))
3095 av |= FILE__OPEN;
3096
3097 return dentry_has_perm(cred, dentry, av);
3098 }
3099
selinux_inode_getattr(const struct path * path)3100 static int selinux_inode_getattr(const struct path *path)
3101 {
3102 return path_has_perm(current_cred(), path, FILE__GETATTR);
3103 }
3104
has_cap_mac_admin(bool audit)3105 static bool has_cap_mac_admin(bool audit)
3106 {
3107 const struct cred *cred = current_cred();
3108 unsigned int opts = audit ? CAP_OPT_NONE : CAP_OPT_NOAUDIT;
3109
3110 if (cap_capable(cred, &init_user_ns, CAP_MAC_ADMIN, opts))
3111 return false;
3112 if (cred_has_capability(cred, CAP_MAC_ADMIN, opts, true))
3113 return false;
3114 return true;
3115 }
3116
selinux_inode_setxattr(struct dentry * dentry,const char * name,const void * value,size_t size,int flags)3117 static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
3118 const void *value, size_t size, int flags)
3119 {
3120 struct inode *inode = d_backing_inode(dentry);
3121 struct inode_security_struct *isec;
3122 struct superblock_security_struct *sbsec;
3123 struct common_audit_data ad;
3124 u32 newsid, sid = current_sid();
3125 int rc = 0;
3126
3127 if (strcmp(name, XATTR_NAME_SELINUX)) {
3128 rc = cap_inode_setxattr(dentry, name, value, size, flags);
3129 if (rc)
3130 return rc;
3131
3132 /* Not an attribute we recognize, so just check the
3133 ordinary setattr permission. */
3134 return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3135 }
3136
3137 if (!selinux_initialized(&selinux_state))
3138 return (inode_owner_or_capable(inode) ? 0 : -EPERM);
3139
3140 sbsec = inode->i_sb->s_security;
3141 if (!(sbsec->flags & SBLABEL_MNT))
3142 return -EOPNOTSUPP;
3143
3144 if (!inode_owner_or_capable(inode))
3145 return -EPERM;
3146
3147 ad.type = LSM_AUDIT_DATA_DENTRY;
3148 ad.u.dentry = dentry;
3149
3150 isec = backing_inode_security(dentry);
3151 rc = avc_has_perm(&selinux_state,
3152 sid, isec->sid, isec->sclass,
3153 FILE__RELABELFROM, &ad);
3154 if (rc)
3155 return rc;
3156
3157 rc = security_context_to_sid(&selinux_state, value, size, &newsid,
3158 GFP_KERNEL);
3159 if (rc == -EINVAL) {
3160 if (!has_cap_mac_admin(true)) {
3161 struct audit_buffer *ab;
3162 size_t audit_size;
3163
3164 /* We strip a nul only if it is at the end, otherwise the
3165 * context contains a nul and we should audit that */
3166 if (value) {
3167 const char *str = value;
3168
3169 if (str[size - 1] == '\0')
3170 audit_size = size - 1;
3171 else
3172 audit_size = size;
3173 } else {
3174 audit_size = 0;
3175 }
3176 ab = audit_log_start(audit_context(),
3177 GFP_ATOMIC, AUDIT_SELINUX_ERR);
3178 audit_log_format(ab, "op=setxattr invalid_context=");
3179 audit_log_n_untrustedstring(ab, value, audit_size);
3180 audit_log_end(ab);
3181
3182 return rc;
3183 }
3184 rc = security_context_to_sid_force(&selinux_state, value,
3185 size, &newsid);
3186 }
3187 if (rc)
3188 return rc;
3189
3190 rc = avc_has_perm(&selinux_state,
3191 sid, newsid, isec->sclass,
3192 FILE__RELABELTO, &ad);
3193 if (rc)
3194 return rc;
3195
3196 rc = security_validate_transition(&selinux_state, isec->sid, newsid,
3197 sid, isec->sclass);
3198 if (rc)
3199 return rc;
3200
3201 return avc_has_perm(&selinux_state,
3202 newsid,
3203 sbsec->sid,
3204 SECCLASS_FILESYSTEM,
3205 FILESYSTEM__ASSOCIATE,
3206 &ad);
3207 }
3208
selinux_inode_post_setxattr(struct dentry * dentry,const char * name,const void * value,size_t size,int flags)3209 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
3210 const void *value, size_t size,
3211 int flags)
3212 {
3213 struct inode *inode = d_backing_inode(dentry);
3214 struct inode_security_struct *isec;
3215 u32 newsid;
3216 int rc;
3217
3218 if (strcmp(name, XATTR_NAME_SELINUX)) {
3219 /* Not an attribute we recognize, so nothing to do. */
3220 return;
3221 }
3222
3223 if (!selinux_initialized(&selinux_state)) {
3224 /* If we haven't even been initialized, then we can't validate
3225 * against a policy, so leave the label as invalid. It may
3226 * resolve to a valid label on the next revalidation try if
3227 * we've since initialized.
3228 */
3229 return;
3230 }
3231
3232 rc = security_context_to_sid_force(&selinux_state, value, size,
3233 &newsid);
3234 if (rc) {
3235 pr_err("SELinux: unable to map context to SID"
3236 "for (%s, %lu), rc=%d\n",
3237 inode->i_sb->s_id, inode->i_ino, -rc);
3238 return;
3239 }
3240
3241 isec = backing_inode_security(dentry);
3242 spin_lock(&isec->lock);
3243 isec->sclass = inode_mode_to_security_class(inode->i_mode);
3244 isec->sid = newsid;
3245 isec->initialized = LABEL_INITIALIZED;
3246 spin_unlock(&isec->lock);
3247
3248 return;
3249 }
3250
selinux_inode_getxattr(struct dentry * dentry,const char * name)3251 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
3252 {
3253 const struct cred *cred = current_cred();
3254
3255 return dentry_has_perm(cred, dentry, FILE__GETATTR);
3256 }
3257
selinux_inode_listxattr(struct dentry * dentry)3258 static int selinux_inode_listxattr(struct dentry *dentry)
3259 {
3260 const struct cred *cred = current_cred();
3261
3262 return dentry_has_perm(cred, dentry, FILE__GETATTR);
3263 }
3264
selinux_inode_removexattr(struct dentry * dentry,const char * name)3265 static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
3266 {
3267 if (strcmp(name, XATTR_NAME_SELINUX)) {
3268 int rc = cap_inode_removexattr(dentry, name);
3269 if (rc)
3270 return rc;
3271
3272 /* Not an attribute we recognize, so just check the
3273 ordinary setattr permission. */
3274 return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3275 }
3276
3277 if (!selinux_initialized(&selinux_state))
3278 return 0;
3279
3280 /* No one is allowed to remove a SELinux security label.
3281 You can change the label, but all data must be labeled. */
3282 return -EACCES;
3283 }
3284
selinux_path_notify(const struct path * path,u64 mask,unsigned int obj_type)3285 static int selinux_path_notify(const struct path *path, u64 mask,
3286 unsigned int obj_type)
3287 {
3288 int ret;
3289 u32 perm;
3290
3291 struct common_audit_data ad;
3292
3293 ad.type = LSM_AUDIT_DATA_PATH;
3294 ad.u.path = *path;
3295
3296 /*
3297 * Set permission needed based on the type of mark being set.
3298 * Performs an additional check for sb watches.
3299 */
3300 switch (obj_type) {
3301 case FSNOTIFY_OBJ_TYPE_VFSMOUNT:
3302 perm = FILE__WATCH_MOUNT;
3303 break;
3304 case FSNOTIFY_OBJ_TYPE_SB:
3305 perm = FILE__WATCH_SB;
3306 ret = superblock_has_perm(current_cred(), path->dentry->d_sb,
3307 FILESYSTEM__WATCH, &ad);
3308 if (ret)
3309 return ret;
3310 break;
3311 case FSNOTIFY_OBJ_TYPE_INODE:
3312 perm = FILE__WATCH;
3313 break;
3314 default:
3315 return -EINVAL;
3316 }
3317
3318 /* blocking watches require the file:watch_with_perm permission */
3319 if (mask & (ALL_FSNOTIFY_PERM_EVENTS))
3320 perm |= FILE__WATCH_WITH_PERM;
3321
3322 /* watches on read-like events need the file:watch_reads permission */
3323 if (mask & (FS_ACCESS | FS_ACCESS_PERM | FS_CLOSE_NOWRITE))
3324 perm |= FILE__WATCH_READS;
3325
3326 return path_has_perm(current_cred(), path, perm);
3327 }
3328
3329 /*
3330 * Copy the inode security context value to the user.
3331 *
3332 * Permission check is handled by selinux_inode_getxattr hook.
3333 */
selinux_inode_getsecurity(struct inode * inode,const char * name,void ** buffer,bool alloc)3334 static int selinux_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc)
3335 {
3336 u32 size;
3337 int error;
3338 char *context = NULL;
3339 struct inode_security_struct *isec;
3340
3341 /*
3342 * If we're not initialized yet, then we can't validate contexts, so
3343 * just let vfs_getxattr fall back to using the on-disk xattr.
3344 */
3345 if (!selinux_initialized(&selinux_state) ||
3346 strcmp(name, XATTR_SELINUX_SUFFIX))
3347 return -EOPNOTSUPP;
3348
3349 /*
3350 * If the caller has CAP_MAC_ADMIN, then get the raw context
3351 * value even if it is not defined by current policy; otherwise,
3352 * use the in-core value under current policy.
3353 * Use the non-auditing forms of the permission checks since
3354 * getxattr may be called by unprivileged processes commonly
3355 * and lack of permission just means that we fall back to the
3356 * in-core context value, not a denial.
3357 */
3358 isec = inode_security(inode);
3359 if (has_cap_mac_admin(false))
3360 error = security_sid_to_context_force(&selinux_state,
3361 isec->sid, &context,
3362 &size);
3363 else
3364 error = security_sid_to_context(&selinux_state, isec->sid,
3365 &context, &size);
3366 if (error)
3367 return error;
3368 error = size;
3369 if (alloc) {
3370 *buffer = context;
3371 goto out_nofree;
3372 }
3373 kfree(context);
3374 out_nofree:
3375 return error;
3376 }
3377
selinux_inode_setsecurity(struct inode * inode,const char * name,const void * value,size_t size,int flags)3378 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
3379 const void *value, size_t size, int flags)
3380 {
3381 struct inode_security_struct *isec = inode_security_novalidate(inode);
3382 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
3383 u32 newsid;
3384 int rc;
3385
3386 if (strcmp(name, XATTR_SELINUX_SUFFIX))
3387 return -EOPNOTSUPP;
3388
3389 if (!(sbsec->flags & SBLABEL_MNT))
3390 return -EOPNOTSUPP;
3391
3392 if (!value || !size)
3393 return -EACCES;
3394
3395 rc = security_context_to_sid(&selinux_state, value, size, &newsid,
3396 GFP_KERNEL);
3397 if (rc)
3398 return rc;
3399
3400 spin_lock(&isec->lock);
3401 isec->sclass = inode_mode_to_security_class(inode->i_mode);
3402 isec->sid = newsid;
3403 isec->initialized = LABEL_INITIALIZED;
3404 spin_unlock(&isec->lock);
3405 return 0;
3406 }
3407
selinux_inode_listsecurity(struct inode * inode,char * buffer,size_t buffer_size)3408 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
3409 {
3410 const int len = sizeof(XATTR_NAME_SELINUX);
3411
3412 if (!selinux_initialized(&selinux_state))
3413 return 0;
3414
3415 if (buffer && len <= buffer_size)
3416 memcpy(buffer, XATTR_NAME_SELINUX, len);
3417 return len;
3418 }
3419
selinux_inode_getsecid(struct inode * inode,u32 * secid)3420 static void selinux_inode_getsecid(struct inode *inode, u32 *secid)
3421 {
3422 struct inode_security_struct *isec = inode_security_novalidate(inode);
3423 *secid = isec->sid;
3424 }
3425
selinux_inode_copy_up(struct dentry * src,struct cred ** new)3426 static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
3427 {
3428 u32 sid;
3429 struct task_security_struct *tsec;
3430 struct cred *new_creds = *new;
3431
3432 if (new_creds == NULL) {
3433 new_creds = prepare_creds();
3434 if (!new_creds)
3435 return -ENOMEM;
3436 }
3437
3438 tsec = selinux_cred(new_creds);
3439 /* Get label from overlay inode and set it in create_sid */
3440 selinux_inode_getsecid(d_inode(src), &sid);
3441 tsec->create_sid = sid;
3442 *new = new_creds;
3443 return 0;
3444 }
3445
selinux_inode_copy_up_xattr(const char * name)3446 static int selinux_inode_copy_up_xattr(const char *name)
3447 {
3448 /* The copy_up hook above sets the initial context on an inode, but we
3449 * don't then want to overwrite it by blindly copying all the lower
3450 * xattrs up. Instead, we have to filter out SELinux-related xattrs.
3451 */
3452 if (strcmp(name, XATTR_NAME_SELINUX) == 0)
3453 return 1; /* Discard */
3454 /*
3455 * Any other attribute apart from SELINUX is not claimed, supported
3456 * by selinux.
3457 */
3458 return -EOPNOTSUPP;
3459 }
3460
3461 /* kernfs node operations */
3462
selinux_kernfs_init_security(struct kernfs_node * kn_dir,struct kernfs_node * kn)3463 static int selinux_kernfs_init_security(struct kernfs_node *kn_dir,
3464 struct kernfs_node *kn)
3465 {
3466 const struct task_security_struct *tsec = selinux_cred(current_cred());
3467 u32 parent_sid, newsid, clen;
3468 int rc;
3469 char *context;
3470
3471 rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, NULL, 0);
3472 if (rc == -ENODATA)
3473 return 0;
3474 else if (rc < 0)
3475 return rc;
3476
3477 clen = (u32)rc;
3478 context = kmalloc(clen, GFP_KERNEL);
3479 if (!context)
3480 return -ENOMEM;
3481
3482 rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, context, clen);
3483 if (rc < 0) {
3484 kfree(context);
3485 return rc;
3486 }
3487
3488 rc = security_context_to_sid(&selinux_state, context, clen, &parent_sid,
3489 GFP_KERNEL);
3490 kfree(context);
3491 if (rc)
3492 return rc;
3493
3494 if (tsec->create_sid) {
3495 newsid = tsec->create_sid;
3496 } else {
3497 u16 secclass = inode_mode_to_security_class(kn->mode);
3498 struct qstr q;
3499
3500 q.name = kn->name;
3501 q.hash_len = hashlen_string(kn_dir, kn->name);
3502
3503 rc = security_transition_sid(&selinux_state, tsec->sid,
3504 parent_sid, secclass, &q,
3505 &newsid);
3506 if (rc)
3507 return rc;
3508 }
3509
3510 rc = security_sid_to_context_force(&selinux_state, newsid,
3511 &context, &clen);
3512 if (rc)
3513 return rc;
3514
3515 rc = kernfs_xattr_set(kn, XATTR_NAME_SELINUX, context, clen,
3516 XATTR_CREATE);
3517 kfree(context);
3518 return rc;
3519 }
3520
3521
3522 /* file security operations */
3523
selinux_revalidate_file_permission(struct file * file,int mask)3524 static int selinux_revalidate_file_permission(struct file *file, int mask)
3525 {
3526 const struct cred *cred = current_cred();
3527 struct inode *inode = file_inode(file);
3528
3529 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
3530 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
3531 mask |= MAY_APPEND;
3532
3533 return file_has_perm(cred, file,
3534 file_mask_to_av(inode->i_mode, mask));
3535 }
3536
selinux_file_permission(struct file * file,int mask)3537 static int selinux_file_permission(struct file *file, int mask)
3538 {
3539 struct inode *inode = file_inode(file);
3540 struct file_security_struct *fsec = selinux_file(file);
3541 struct inode_security_struct *isec;
3542 u32 sid = current_sid();
3543
3544 if (!mask)
3545 /* No permission to check. Existence test. */
3546 return 0;
3547
3548 isec = inode_security(inode);
3549 if (sid == fsec->sid && fsec->isid == isec->sid &&
3550 fsec->pseqno == avc_policy_seqno(&selinux_state))
3551 /* No change since file_open check. */
3552 return 0;
3553
3554 return selinux_revalidate_file_permission(file, mask);
3555 }
3556
selinux_file_alloc_security(struct file * file)3557 static int selinux_file_alloc_security(struct file *file)
3558 {
3559 struct file_security_struct *fsec = selinux_file(file);
3560 u32 sid = current_sid();
3561
3562 fsec->sid = sid;
3563 fsec->fown_sid = sid;
3564
3565 return 0;
3566 }
3567
3568 /*
3569 * Check whether a task has the ioctl permission and cmd
3570 * operation to an inode.
3571 */
ioctl_has_perm(const struct cred * cred,struct file * file,u32 requested,u16 cmd)3572 static int ioctl_has_perm(const struct cred *cred, struct file *file,
3573 u32 requested, u16 cmd)
3574 {
3575 struct common_audit_data ad;
3576 struct file_security_struct *fsec = selinux_file(file);
3577 struct inode *inode = file_inode(file);
3578 struct inode_security_struct *isec;
3579 struct lsm_ioctlop_audit ioctl;
3580 u32 ssid = cred_sid(cred);
3581 int rc;
3582 u8 driver = cmd >> 8;
3583 u8 xperm = cmd & 0xff;
3584
3585 ad.type = LSM_AUDIT_DATA_IOCTL_OP;
3586 ad.u.op = &ioctl;
3587 ad.u.op->cmd = cmd;
3588 ad.u.op->path = file->f_path;
3589
3590 if (ssid != fsec->sid) {
3591 rc = avc_has_perm(&selinux_state,
3592 ssid, fsec->sid,
3593 SECCLASS_FD,
3594 FD__USE,
3595 &ad);
3596 if (rc)
3597 goto out;
3598 }
3599
3600 if (unlikely(IS_PRIVATE(inode)))
3601 return 0;
3602
3603 isec = inode_security(inode);
3604 rc = avc_has_extended_perms(&selinux_state,
3605 ssid, isec->sid, isec->sclass,
3606 requested, driver, xperm, &ad);
3607 out:
3608 return rc;
3609 }
3610
selinux_file_ioctl(struct file * file,unsigned int cmd,unsigned long arg)3611 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
3612 unsigned long arg)
3613 {
3614 const struct cred *cred = current_cred();
3615 int error = 0;
3616
3617 switch (cmd) {
3618 case FIONREAD:
3619 case FIBMAP:
3620 case FIGETBSZ:
3621 case FS_IOC_GETFLAGS:
3622 case FS_IOC_GETVERSION:
3623 error = file_has_perm(cred, file, FILE__GETATTR);
3624 break;
3625
3626 case FS_IOC_SETFLAGS:
3627 case FS_IOC_SETVERSION:
3628 error = file_has_perm(cred, file, FILE__SETATTR);
3629 break;
3630
3631 /* sys_ioctl() checks */
3632 case FIONBIO:
3633 case FIOASYNC:
3634 error = file_has_perm(cred, file, 0);
3635 break;
3636
3637 case KDSKBENT:
3638 case KDSKBSENT:
3639 error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3640 CAP_OPT_NONE, true);
3641 break;
3642
3643 /* default case assumes that the command will go
3644 * to the file's ioctl() function.
3645 */
3646 default:
3647 error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3648 }
3649 return error;
3650 }
3651
3652 static int default_noexec __ro_after_init;
3653
file_map_prot_check(struct file * file,unsigned long prot,int shared)3654 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3655 {
3656 const struct cred *cred = current_cred();
3657 u32 sid = cred_sid(cred);
3658 int rc = 0;
3659
3660 if (default_noexec &&
3661 (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) ||
3662 (!shared && (prot & PROT_WRITE)))) {
3663 /*
3664 * We are making executable an anonymous mapping or a
3665 * private file mapping that will also be writable.
3666 * This has an additional check.
3667 */
3668 rc = avc_has_perm(&selinux_state,
3669 sid, sid, SECCLASS_PROCESS,
3670 PROCESS__EXECMEM, NULL);
3671 if (rc)
3672 goto error;
3673 }
3674
3675 if (file) {
3676 /* read access is always possible with a mapping */
3677 u32 av = FILE__READ;
3678
3679 /* write access only matters if the mapping is shared */
3680 if (shared && (prot & PROT_WRITE))
3681 av |= FILE__WRITE;
3682
3683 if (prot & PROT_EXEC)
3684 av |= FILE__EXECUTE;
3685
3686 return file_has_perm(cred, file, av);
3687 }
3688
3689 error:
3690 return rc;
3691 }
3692
selinux_mmap_addr(unsigned long addr)3693 static int selinux_mmap_addr(unsigned long addr)
3694 {
3695 int rc = 0;
3696
3697 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3698 u32 sid = current_sid();
3699 rc = avc_has_perm(&selinux_state,
3700 sid, sid, SECCLASS_MEMPROTECT,
3701 MEMPROTECT__MMAP_ZERO, NULL);
3702 }
3703
3704 return rc;
3705 }
3706
selinux_mmap_file(struct file * file,unsigned long reqprot,unsigned long prot,unsigned long flags)3707 static int selinux_mmap_file(struct file *file, unsigned long reqprot,
3708 unsigned long prot, unsigned long flags)
3709 {
3710 struct common_audit_data ad;
3711 int rc;
3712
3713 if (file) {
3714 ad.type = LSM_AUDIT_DATA_FILE;
3715 ad.u.file = file;
3716 rc = inode_has_perm(current_cred(), file_inode(file),
3717 FILE__MAP, &ad);
3718 if (rc)
3719 return rc;
3720 }
3721
3722 if (checkreqprot_get(&selinux_state))
3723 prot = reqprot;
3724
3725 return file_map_prot_check(file, prot,
3726 (flags & MAP_TYPE) == MAP_SHARED);
3727 }
3728
selinux_file_mprotect(struct vm_area_struct * vma,unsigned long reqprot,unsigned long prot)3729 static int selinux_file_mprotect(struct vm_area_struct *vma,
3730 unsigned long reqprot,
3731 unsigned long prot)
3732 {
3733 const struct cred *cred = current_cred();
3734 u32 sid = cred_sid(cred);
3735
3736 if (checkreqprot_get(&selinux_state))
3737 prot = reqprot;
3738
3739 if (default_noexec &&
3740 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3741 int rc = 0;
3742 if (vma->vm_start >= vma->vm_mm->start_brk &&
3743 vma->vm_end <= vma->vm_mm->brk) {
3744 rc = avc_has_perm(&selinux_state,
3745 sid, sid, SECCLASS_PROCESS,
3746 PROCESS__EXECHEAP, NULL);
3747 } else if (!vma->vm_file &&
3748 ((vma->vm_start <= vma->vm_mm->start_stack &&
3749 vma->vm_end >= vma->vm_mm->start_stack) ||
3750 vma_is_stack_for_current(vma))) {
3751 rc = avc_has_perm(&selinux_state,
3752 sid, sid, SECCLASS_PROCESS,
3753 PROCESS__EXECSTACK, NULL);
3754 } else if (vma->vm_file && vma->anon_vma) {
3755 /*
3756 * We are making executable a file mapping that has
3757 * had some COW done. Since pages might have been
3758 * written, check ability to execute the possibly
3759 * modified content. This typically should only
3760 * occur for text relocations.
3761 */
3762 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3763 }
3764 if (rc)
3765 return rc;
3766 }
3767
3768 return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3769 }
3770
selinux_file_lock(struct file * file,unsigned int cmd)3771 static int selinux_file_lock(struct file *file, unsigned int cmd)
3772 {
3773 const struct cred *cred = current_cred();
3774
3775 return file_has_perm(cred, file, FILE__LOCK);
3776 }
3777
selinux_file_fcntl(struct file * file,unsigned int cmd,unsigned long arg)3778 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3779 unsigned long arg)
3780 {
3781 const struct cred *cred = current_cred();
3782 int err = 0;
3783
3784 switch (cmd) {
3785 case F_SETFL:
3786 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3787 err = file_has_perm(cred, file, FILE__WRITE);
3788 break;
3789 }
3790 fallthrough;
3791 case F_SETOWN:
3792 case F_SETSIG:
3793 case F_GETFL:
3794 case F_GETOWN:
3795 case F_GETSIG:
3796 case F_GETOWNER_UIDS:
3797 /* Just check FD__USE permission */
3798 err = file_has_perm(cred, file, 0);
3799 break;
3800 case F_GETLK:
3801 case F_SETLK:
3802 case F_SETLKW:
3803 case F_OFD_GETLK:
3804 case F_OFD_SETLK:
3805 case F_OFD_SETLKW:
3806 #if BITS_PER_LONG == 32
3807 case F_GETLK64:
3808 case F_SETLK64:
3809 case F_SETLKW64:
3810 #endif
3811 err = file_has_perm(cred, file, FILE__LOCK);
3812 break;
3813 }
3814
3815 return err;
3816 }
3817
selinux_file_set_fowner(struct file * file)3818 static void selinux_file_set_fowner(struct file *file)
3819 {
3820 struct file_security_struct *fsec;
3821
3822 fsec = selinux_file(file);
3823 fsec->fown_sid = current_sid();
3824 }
3825
selinux_file_send_sigiotask(struct task_struct * tsk,struct fown_struct * fown,int signum)3826 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3827 struct fown_struct *fown, int signum)
3828 {
3829 struct file *file;
3830 u32 sid = task_sid(tsk);
3831 u32 perm;
3832 struct file_security_struct *fsec;
3833
3834 /* struct fown_struct is never outside the context of a struct file */
3835 file = container_of(fown, struct file, f_owner);
3836
3837 fsec = selinux_file(file);
3838
3839 if (!signum)
3840 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3841 else
3842 perm = signal_to_av(signum);
3843
3844 return avc_has_perm(&selinux_state,
3845 fsec->fown_sid, sid,
3846 SECCLASS_PROCESS, perm, NULL);
3847 }
3848
selinux_file_receive(struct file * file)3849 static int selinux_file_receive(struct file *file)
3850 {
3851 const struct cred *cred = current_cred();
3852
3853 return file_has_perm(cred, file, file_to_av(file));
3854 }
3855
selinux_file_open(struct file * file)3856 static int selinux_file_open(struct file *file)
3857 {
3858 struct file_security_struct *fsec;
3859 struct inode_security_struct *isec;
3860
3861 fsec = selinux_file(file);
3862 isec = inode_security(file_inode(file));
3863 /*
3864 * Save inode label and policy sequence number
3865 * at open-time so that selinux_file_permission
3866 * can determine whether revalidation is necessary.
3867 * Task label is already saved in the file security
3868 * struct as its SID.
3869 */
3870 fsec->isid = isec->sid;
3871 fsec->pseqno = avc_policy_seqno(&selinux_state);
3872 /*
3873 * Since the inode label or policy seqno may have changed
3874 * between the selinux_inode_permission check and the saving
3875 * of state above, recheck that access is still permitted.
3876 * Otherwise, access might never be revalidated against the
3877 * new inode label or new policy.
3878 * This check is not redundant - do not remove.
3879 */
3880 return file_path_has_perm(file->f_cred, file, open_file_to_av(file));
3881 }
3882
3883 /* task security operations */
3884
selinux_task_alloc(struct task_struct * task,unsigned long clone_flags)3885 static int selinux_task_alloc(struct task_struct *task,
3886 unsigned long clone_flags)
3887 {
3888 u32 sid = current_sid();
3889
3890 return avc_has_perm(&selinux_state,
3891 sid, sid, SECCLASS_PROCESS, PROCESS__FORK, NULL);
3892 }
3893
3894 /*
3895 * prepare a new set of credentials for modification
3896 */
selinux_cred_prepare(struct cred * new,const struct cred * old,gfp_t gfp)3897 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3898 gfp_t gfp)
3899 {
3900 const struct task_security_struct *old_tsec = selinux_cred(old);
3901 struct task_security_struct *tsec = selinux_cred(new);
3902
3903 *tsec = *old_tsec;
3904 return 0;
3905 }
3906
3907 /*
3908 * transfer the SELinux data to a blank set of creds
3909 */
selinux_cred_transfer(struct cred * new,const struct cred * old)3910 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
3911 {
3912 const struct task_security_struct *old_tsec = selinux_cred(old);
3913 struct task_security_struct *tsec = selinux_cred(new);
3914
3915 *tsec = *old_tsec;
3916 }
3917
selinux_cred_getsecid(const struct cred * c,u32 * secid)3918 static void selinux_cred_getsecid(const struct cred *c, u32 *secid)
3919 {
3920 *secid = cred_sid(c);
3921 }
3922
3923 /*
3924 * set the security data for a kernel service
3925 * - all the creation contexts are set to unlabelled
3926 */
selinux_kernel_act_as(struct cred * new,u32 secid)3927 static int selinux_kernel_act_as(struct cred *new, u32 secid)
3928 {
3929 struct task_security_struct *tsec = selinux_cred(new);
3930 u32 sid = current_sid();
3931 int ret;
3932
3933 ret = avc_has_perm(&selinux_state,
3934 sid, secid,
3935 SECCLASS_KERNEL_SERVICE,
3936 KERNEL_SERVICE__USE_AS_OVERRIDE,
3937 NULL);
3938 if (ret == 0) {
3939 tsec->sid = secid;
3940 tsec->create_sid = 0;
3941 tsec->keycreate_sid = 0;
3942 tsec->sockcreate_sid = 0;
3943 }
3944 return ret;
3945 }
3946
3947 /*
3948 * set the file creation context in a security record to the same as the
3949 * objective context of the specified inode
3950 */
selinux_kernel_create_files_as(struct cred * new,struct inode * inode)3951 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
3952 {
3953 struct inode_security_struct *isec = inode_security(inode);
3954 struct task_security_struct *tsec = selinux_cred(new);
3955 u32 sid = current_sid();
3956 int ret;
3957
3958 ret = avc_has_perm(&selinux_state,
3959 sid, isec->sid,
3960 SECCLASS_KERNEL_SERVICE,
3961 KERNEL_SERVICE__CREATE_FILES_AS,
3962 NULL);
3963
3964 if (ret == 0)
3965 tsec->create_sid = isec->sid;
3966 return ret;
3967 }
3968
selinux_kernel_module_request(char * kmod_name)3969 static int selinux_kernel_module_request(char *kmod_name)
3970 {
3971 struct common_audit_data ad;
3972
3973 ad.type = LSM_AUDIT_DATA_KMOD;
3974 ad.u.kmod_name = kmod_name;
3975
3976 return avc_has_perm(&selinux_state,
3977 current_sid(), SECINITSID_KERNEL, SECCLASS_SYSTEM,
3978 SYSTEM__MODULE_REQUEST, &ad);
3979 }
3980
selinux_kernel_module_from_file(struct file * file)3981 static int selinux_kernel_module_from_file(struct file *file)
3982 {
3983 struct common_audit_data ad;
3984 struct inode_security_struct *isec;
3985 struct file_security_struct *fsec;
3986 u32 sid = current_sid();
3987 int rc;
3988
3989 /* init_module */
3990 if (file == NULL)
3991 return avc_has_perm(&selinux_state,
3992 sid, sid, SECCLASS_SYSTEM,
3993 SYSTEM__MODULE_LOAD, NULL);
3994
3995 /* finit_module */
3996
3997 ad.type = LSM_AUDIT_DATA_FILE;
3998 ad.u.file = file;
3999
4000 fsec = selinux_file(file);
4001 if (sid != fsec->sid) {
4002 rc = avc_has_perm(&selinux_state,
4003 sid, fsec->sid, SECCLASS_FD, FD__USE, &ad);
4004 if (rc)
4005 return rc;
4006 }
4007
4008 isec = inode_security(file_inode(file));
4009 return avc_has_perm(&selinux_state,
4010 sid, isec->sid, SECCLASS_SYSTEM,
4011 SYSTEM__MODULE_LOAD, &ad);
4012 }
4013
selinux_kernel_read_file(struct file * file,enum kernel_read_file_id id,bool contents)4014 static int selinux_kernel_read_file(struct file *file,
4015 enum kernel_read_file_id id,
4016 bool contents)
4017 {
4018 int rc = 0;
4019
4020 switch (id) {
4021 case READING_MODULE:
4022 rc = selinux_kernel_module_from_file(contents ? file : NULL);
4023 break;
4024 default:
4025 break;
4026 }
4027
4028 return rc;
4029 }
4030
selinux_kernel_load_data(enum kernel_load_data_id id,bool contents)4031 static int selinux_kernel_load_data(enum kernel_load_data_id id, bool contents)
4032 {
4033 int rc = 0;
4034
4035 switch (id) {
4036 case LOADING_MODULE:
4037 rc = selinux_kernel_module_from_file(NULL);
4038 default:
4039 break;
4040 }
4041
4042 return rc;
4043 }
4044
selinux_task_setpgid(struct task_struct * p,pid_t pgid)4045 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
4046 {
4047 return avc_has_perm(&selinux_state,
4048 current_sid(), task_sid(p), SECCLASS_PROCESS,
4049 PROCESS__SETPGID, NULL);
4050 }
4051
selinux_task_getpgid(struct task_struct * p)4052 static int selinux_task_getpgid(struct task_struct *p)
4053 {
4054 return avc_has_perm(&selinux_state,
4055 current_sid(), task_sid(p), SECCLASS_PROCESS,
4056 PROCESS__GETPGID, NULL);
4057 }
4058
selinux_task_getsid(struct task_struct * p)4059 static int selinux_task_getsid(struct task_struct *p)
4060 {
4061 return avc_has_perm(&selinux_state,
4062 current_sid(), task_sid(p), SECCLASS_PROCESS,
4063 PROCESS__GETSESSION, NULL);
4064 }
4065
selinux_task_getsecid(struct task_struct * p,u32 * secid)4066 static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
4067 {
4068 *secid = task_sid(p);
4069 }
4070
selinux_task_setnice(struct task_struct * p,int nice)4071 static int selinux_task_setnice(struct task_struct *p, int nice)
4072 {
4073 return avc_has_perm(&selinux_state,
4074 current_sid(), task_sid(p), SECCLASS_PROCESS,
4075 PROCESS__SETSCHED, NULL);
4076 }
4077
selinux_task_setioprio(struct task_struct * p,int ioprio)4078 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
4079 {
4080 return avc_has_perm(&selinux_state,
4081 current_sid(), task_sid(p), SECCLASS_PROCESS,
4082 PROCESS__SETSCHED, NULL);
4083 }
4084
selinux_task_getioprio(struct task_struct * p)4085 static int selinux_task_getioprio(struct task_struct *p)
4086 {
4087 return avc_has_perm(&selinux_state,
4088 current_sid(), task_sid(p), SECCLASS_PROCESS,
4089 PROCESS__GETSCHED, NULL);
4090 }
4091
selinux_task_prlimit(const struct cred * cred,const struct cred * tcred,unsigned int flags)4092 static int selinux_task_prlimit(const struct cred *cred, const struct cred *tcred,
4093 unsigned int flags)
4094 {
4095 u32 av = 0;
4096
4097 if (!flags)
4098 return 0;
4099 if (flags & LSM_PRLIMIT_WRITE)
4100 av |= PROCESS__SETRLIMIT;
4101 if (flags & LSM_PRLIMIT_READ)
4102 av |= PROCESS__GETRLIMIT;
4103 return avc_has_perm(&selinux_state,
4104 cred_sid(cred), cred_sid(tcred),
4105 SECCLASS_PROCESS, av, NULL);
4106 }
4107
selinux_task_setrlimit(struct task_struct * p,unsigned int resource,struct rlimit * new_rlim)4108 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
4109 struct rlimit *new_rlim)
4110 {
4111 struct rlimit *old_rlim = p->signal->rlim + resource;
4112
4113 /* Control the ability to change the hard limit (whether
4114 lowering or raising it), so that the hard limit can
4115 later be used as a safe reset point for the soft limit
4116 upon context transitions. See selinux_bprm_committing_creds. */
4117 if (old_rlim->rlim_max != new_rlim->rlim_max)
4118 return avc_has_perm(&selinux_state,
4119 current_sid(), task_sid(p),
4120 SECCLASS_PROCESS, PROCESS__SETRLIMIT, NULL);
4121
4122 return 0;
4123 }
4124
selinux_task_setscheduler(struct task_struct * p)4125 static int selinux_task_setscheduler(struct task_struct *p)
4126 {
4127 return avc_has_perm(&selinux_state,
4128 current_sid(), task_sid(p), SECCLASS_PROCESS,
4129 PROCESS__SETSCHED, NULL);
4130 }
4131
selinux_task_getscheduler(struct task_struct * p)4132 static int selinux_task_getscheduler(struct task_struct *p)
4133 {
4134 return avc_has_perm(&selinux_state,
4135 current_sid(), task_sid(p), SECCLASS_PROCESS,
4136 PROCESS__GETSCHED, NULL);
4137 }
4138
selinux_task_movememory(struct task_struct * p)4139 static int selinux_task_movememory(struct task_struct *p)
4140 {
4141 return avc_has_perm(&selinux_state,
4142 current_sid(), task_sid(p), SECCLASS_PROCESS,
4143 PROCESS__SETSCHED, NULL);
4144 }
4145
selinux_task_kill(struct task_struct * p,struct kernel_siginfo * info,int sig,const struct cred * cred)4146 static int selinux_task_kill(struct task_struct *p, struct kernel_siginfo *info,
4147 int sig, const struct cred *cred)
4148 {
4149 u32 secid;
4150 u32 perm;
4151
4152 if (!sig)
4153 perm = PROCESS__SIGNULL; /* null signal; existence test */
4154 else
4155 perm = signal_to_av(sig);
4156 if (!cred)
4157 secid = current_sid();
4158 else
4159 secid = cred_sid(cred);
4160 return avc_has_perm(&selinux_state,
4161 secid, task_sid(p), SECCLASS_PROCESS, perm, NULL);
4162 }
4163
selinux_task_to_inode(struct task_struct * p,struct inode * inode)4164 static void selinux_task_to_inode(struct task_struct *p,
4165 struct inode *inode)
4166 {
4167 struct inode_security_struct *isec = selinux_inode(inode);
4168 u32 sid = task_sid(p);
4169
4170 spin_lock(&isec->lock);
4171 isec->sclass = inode_mode_to_security_class(inode->i_mode);
4172 isec->sid = sid;
4173 isec->initialized = LABEL_INITIALIZED;
4174 spin_unlock(&isec->lock);
4175 }
4176
4177 /* Returns error only if unable to parse addresses */
selinux_parse_skb_ipv4(struct sk_buff * skb,struct common_audit_data * ad,u8 * proto)4178 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
4179 struct common_audit_data *ad, u8 *proto)
4180 {
4181 int offset, ihlen, ret = -EINVAL;
4182 struct iphdr _iph, *ih;
4183
4184 offset = skb_network_offset(skb);
4185 ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
4186 if (ih == NULL)
4187 goto out;
4188
4189 ihlen = ih->ihl * 4;
4190 if (ihlen < sizeof(_iph))
4191 goto out;
4192
4193 ad->u.net->v4info.saddr = ih->saddr;
4194 ad->u.net->v4info.daddr = ih->daddr;
4195 ret = 0;
4196
4197 if (proto)
4198 *proto = ih->protocol;
4199
4200 switch (ih->protocol) {
4201 case IPPROTO_TCP: {
4202 struct tcphdr _tcph, *th;
4203
4204 if (ntohs(ih->frag_off) & IP_OFFSET)
4205 break;
4206
4207 offset += ihlen;
4208 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4209 if (th == NULL)
4210 break;
4211
4212 ad->u.net->sport = th->source;
4213 ad->u.net->dport = th->dest;
4214 break;
4215 }
4216
4217 case IPPROTO_UDP: {
4218 struct udphdr _udph, *uh;
4219
4220 if (ntohs(ih->frag_off) & IP_OFFSET)
4221 break;
4222
4223 offset += ihlen;
4224 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4225 if (uh == NULL)
4226 break;
4227
4228 ad->u.net->sport = uh->source;
4229 ad->u.net->dport = uh->dest;
4230 break;
4231 }
4232
4233 case IPPROTO_DCCP: {
4234 struct dccp_hdr _dccph, *dh;
4235
4236 if (ntohs(ih->frag_off) & IP_OFFSET)
4237 break;
4238
4239 offset += ihlen;
4240 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4241 if (dh == NULL)
4242 break;
4243
4244 ad->u.net->sport = dh->dccph_sport;
4245 ad->u.net->dport = dh->dccph_dport;
4246 break;
4247 }
4248
4249 #if IS_ENABLED(CONFIG_IP_SCTP)
4250 case IPPROTO_SCTP: {
4251 struct sctphdr _sctph, *sh;
4252
4253 if (ntohs(ih->frag_off) & IP_OFFSET)
4254 break;
4255
4256 offset += ihlen;
4257 sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
4258 if (sh == NULL)
4259 break;
4260
4261 ad->u.net->sport = sh->source;
4262 ad->u.net->dport = sh->dest;
4263 break;
4264 }
4265 #endif
4266 default:
4267 break;
4268 }
4269 out:
4270 return ret;
4271 }
4272
4273 #if IS_ENABLED(CONFIG_IPV6)
4274
4275 /* Returns error only if unable to parse addresses */
selinux_parse_skb_ipv6(struct sk_buff * skb,struct common_audit_data * ad,u8 * proto)4276 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
4277 struct common_audit_data *ad, u8 *proto)
4278 {
4279 u8 nexthdr;
4280 int ret = -EINVAL, offset;
4281 struct ipv6hdr _ipv6h, *ip6;
4282 __be16 frag_off;
4283
4284 offset = skb_network_offset(skb);
4285 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
4286 if (ip6 == NULL)
4287 goto out;
4288
4289 ad->u.net->v6info.saddr = ip6->saddr;
4290 ad->u.net->v6info.daddr = ip6->daddr;
4291 ret = 0;
4292
4293 nexthdr = ip6->nexthdr;
4294 offset += sizeof(_ipv6h);
4295 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
4296 if (offset < 0)
4297 goto out;
4298
4299 if (proto)
4300 *proto = nexthdr;
4301
4302 switch (nexthdr) {
4303 case IPPROTO_TCP: {
4304 struct tcphdr _tcph, *th;
4305
4306 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4307 if (th == NULL)
4308 break;
4309
4310 ad->u.net->sport = th->source;
4311 ad->u.net->dport = th->dest;
4312 break;
4313 }
4314
4315 case IPPROTO_UDP: {
4316 struct udphdr _udph, *uh;
4317
4318 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4319 if (uh == NULL)
4320 break;
4321
4322 ad->u.net->sport = uh->source;
4323 ad->u.net->dport = uh->dest;
4324 break;
4325 }
4326
4327 case IPPROTO_DCCP: {
4328 struct dccp_hdr _dccph, *dh;
4329
4330 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4331 if (dh == NULL)
4332 break;
4333
4334 ad->u.net->sport = dh->dccph_sport;
4335 ad->u.net->dport = dh->dccph_dport;
4336 break;
4337 }
4338
4339 #if IS_ENABLED(CONFIG_IP_SCTP)
4340 case IPPROTO_SCTP: {
4341 struct sctphdr _sctph, *sh;
4342
4343 sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
4344 if (sh == NULL)
4345 break;
4346
4347 ad->u.net->sport = sh->source;
4348 ad->u.net->dport = sh->dest;
4349 break;
4350 }
4351 #endif
4352 /* includes fragments */
4353 default:
4354 break;
4355 }
4356 out:
4357 return ret;
4358 }
4359
4360 #endif /* IPV6 */
4361
selinux_parse_skb(struct sk_buff * skb,struct common_audit_data * ad,char ** _addrp,int src,u8 * proto)4362 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
4363 char **_addrp, int src, u8 *proto)
4364 {
4365 char *addrp;
4366 int ret;
4367
4368 switch (ad->u.net->family) {
4369 case PF_INET:
4370 ret = selinux_parse_skb_ipv4(skb, ad, proto);
4371 if (ret)
4372 goto parse_error;
4373 addrp = (char *)(src ? &ad->u.net->v4info.saddr :
4374 &ad->u.net->v4info.daddr);
4375 goto okay;
4376
4377 #if IS_ENABLED(CONFIG_IPV6)
4378 case PF_INET6:
4379 ret = selinux_parse_skb_ipv6(skb, ad, proto);
4380 if (ret)
4381 goto parse_error;
4382 addrp = (char *)(src ? &ad->u.net->v6info.saddr :
4383 &ad->u.net->v6info.daddr);
4384 goto okay;
4385 #endif /* IPV6 */
4386 default:
4387 addrp = NULL;
4388 goto okay;
4389 }
4390
4391 parse_error:
4392 pr_warn(
4393 "SELinux: failure in selinux_parse_skb(),"
4394 " unable to parse packet\n");
4395 return ret;
4396
4397 okay:
4398 if (_addrp)
4399 *_addrp = addrp;
4400 return 0;
4401 }
4402
4403 /**
4404 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
4405 * @skb: the packet
4406 * @family: protocol family
4407 * @sid: the packet's peer label SID
4408 *
4409 * Description:
4410 * Check the various different forms of network peer labeling and determine
4411 * the peer label/SID for the packet; most of the magic actually occurs in
4412 * the security server function security_net_peersid_cmp(). The function
4413 * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
4414 * or -EACCES if @sid is invalid due to inconsistencies with the different
4415 * peer labels.
4416 *
4417 */
selinux_skb_peerlbl_sid(struct sk_buff * skb,u16 family,u32 * sid)4418 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
4419 {
4420 int err;
4421 u32 xfrm_sid;
4422 u32 nlbl_sid;
4423 u32 nlbl_type;
4424
4425 err = selinux_xfrm_skb_sid(skb, &xfrm_sid);
4426 if (unlikely(err))
4427 return -EACCES;
4428 err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
4429 if (unlikely(err))
4430 return -EACCES;
4431
4432 err = security_net_peersid_resolve(&selinux_state, nlbl_sid,
4433 nlbl_type, xfrm_sid, sid);
4434 if (unlikely(err)) {
4435 pr_warn(
4436 "SELinux: failure in selinux_skb_peerlbl_sid(),"
4437 " unable to determine packet's peer label\n");
4438 return -EACCES;
4439 }
4440
4441 return 0;
4442 }
4443
4444 /**
4445 * selinux_conn_sid - Determine the child socket label for a connection
4446 * @sk_sid: the parent socket's SID
4447 * @skb_sid: the packet's SID
4448 * @conn_sid: the resulting connection SID
4449 *
4450 * If @skb_sid is valid then the user:role:type information from @sk_sid is
4451 * combined with the MLS information from @skb_sid in order to create
4452 * @conn_sid. If @skb_sid is not valid then @conn_sid is simply a copy
4453 * of @sk_sid. Returns zero on success, negative values on failure.
4454 *
4455 */
selinux_conn_sid(u32 sk_sid,u32 skb_sid,u32 * conn_sid)4456 static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid)
4457 {
4458 int err = 0;
4459
4460 if (skb_sid != SECSID_NULL)
4461 err = security_sid_mls_copy(&selinux_state, sk_sid, skb_sid,
4462 conn_sid);
4463 else
4464 *conn_sid = sk_sid;
4465
4466 return err;
4467 }
4468
4469 /* socket security operations */
4470
socket_sockcreate_sid(const struct task_security_struct * tsec,u16 secclass,u32 * socksid)4471 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
4472 u16 secclass, u32 *socksid)
4473 {
4474 if (tsec->sockcreate_sid > SECSID_NULL) {
4475 *socksid = tsec->sockcreate_sid;
4476 return 0;
4477 }
4478
4479 return security_transition_sid(&selinux_state, tsec->sid, tsec->sid,
4480 secclass, NULL, socksid);
4481 }
4482
sock_has_perm(struct sock * sk,u32 perms)4483 static int sock_has_perm(struct sock *sk, u32 perms)
4484 {
4485 struct sk_security_struct *sksec = sk->sk_security;
4486 struct common_audit_data ad;
4487 struct lsm_network_audit net = {0,};
4488
4489 if (sksec->sid == SECINITSID_KERNEL)
4490 return 0;
4491
4492 ad.type = LSM_AUDIT_DATA_NET;
4493 ad.u.net = &net;
4494 ad.u.net->sk = sk;
4495
4496 return avc_has_perm(&selinux_state,
4497 current_sid(), sksec->sid, sksec->sclass, perms,
4498 &ad);
4499 }
4500
selinux_socket_create(int family,int type,int protocol,int kern)4501 static int selinux_socket_create(int family, int type,
4502 int protocol, int kern)
4503 {
4504 const struct task_security_struct *tsec = selinux_cred(current_cred());
4505 u32 newsid;
4506 u16 secclass;
4507 int rc;
4508
4509 if (kern)
4510 return 0;
4511
4512 secclass = socket_type_to_security_class(family, type, protocol);
4513 rc = socket_sockcreate_sid(tsec, secclass, &newsid);
4514 if (rc)
4515 return rc;
4516
4517 return avc_has_perm(&selinux_state,
4518 tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
4519 }
4520
selinux_socket_post_create(struct socket * sock,int family,int type,int protocol,int kern)4521 static int selinux_socket_post_create(struct socket *sock, int family,
4522 int type, int protocol, int kern)
4523 {
4524 const struct task_security_struct *tsec = selinux_cred(current_cred());
4525 struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
4526 struct sk_security_struct *sksec;
4527 u16 sclass = socket_type_to_security_class(family, type, protocol);
4528 u32 sid = SECINITSID_KERNEL;
4529 int err = 0;
4530
4531 if (!kern) {
4532 err = socket_sockcreate_sid(tsec, sclass, &sid);
4533 if (err)
4534 return err;
4535 }
4536
4537 isec->sclass = sclass;
4538 isec->sid = sid;
4539 isec->initialized = LABEL_INITIALIZED;
4540
4541 if (sock->sk) {
4542 sksec = sock->sk->sk_security;
4543 sksec->sclass = sclass;
4544 sksec->sid = sid;
4545 /* Allows detection of the first association on this socket */
4546 if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4547 sksec->sctp_assoc_state = SCTP_ASSOC_UNSET;
4548
4549 err = selinux_netlbl_socket_post_create(sock->sk, family);
4550 }
4551
4552 return err;
4553 }
4554
selinux_socket_socketpair(struct socket * socka,struct socket * sockb)4555 static int selinux_socket_socketpair(struct socket *socka,
4556 struct socket *sockb)
4557 {
4558 struct sk_security_struct *sksec_a = socka->sk->sk_security;
4559 struct sk_security_struct *sksec_b = sockb->sk->sk_security;
4560
4561 sksec_a->peer_sid = sksec_b->sid;
4562 sksec_b->peer_sid = sksec_a->sid;
4563
4564 return 0;
4565 }
4566
4567 /* Range of port numbers used to automatically bind.
4568 Need to determine whether we should perform a name_bind
4569 permission check between the socket and the port number. */
4570
selinux_socket_bind(struct socket * sock,struct sockaddr * address,int addrlen)4571 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
4572 {
4573 struct sock *sk = sock->sk;
4574 struct sk_security_struct *sksec = sk->sk_security;
4575 u16 family;
4576 int err;
4577
4578 err = sock_has_perm(sk, SOCKET__BIND);
4579 if (err)
4580 goto out;
4581
4582 /* If PF_INET or PF_INET6, check name_bind permission for the port. */
4583 family = sk->sk_family;
4584 if (family == PF_INET || family == PF_INET6) {
4585 char *addrp;
4586 struct common_audit_data ad;
4587 struct lsm_network_audit net = {0,};
4588 struct sockaddr_in *addr4 = NULL;
4589 struct sockaddr_in6 *addr6 = NULL;
4590 u16 family_sa;
4591 unsigned short snum;
4592 u32 sid, node_perm;
4593
4594 /*
4595 * sctp_bindx(3) calls via selinux_sctp_bind_connect()
4596 * that validates multiple binding addresses. Because of this
4597 * need to check address->sa_family as it is possible to have
4598 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
4599 */
4600 if (addrlen < offsetofend(struct sockaddr, sa_family))
4601 return -EINVAL;
4602 family_sa = address->sa_family;
4603 switch (family_sa) {
4604 case AF_UNSPEC:
4605 case AF_INET:
4606 if (addrlen < sizeof(struct sockaddr_in))
4607 return -EINVAL;
4608 addr4 = (struct sockaddr_in *)address;
4609 if (family_sa == AF_UNSPEC) {
4610 /* see __inet_bind(), we only want to allow
4611 * AF_UNSPEC if the address is INADDR_ANY
4612 */
4613 if (addr4->sin_addr.s_addr != htonl(INADDR_ANY))
4614 goto err_af;
4615 family_sa = AF_INET;
4616 }
4617 snum = ntohs(addr4->sin_port);
4618 addrp = (char *)&addr4->sin_addr.s_addr;
4619 break;
4620 case AF_INET6:
4621 if (addrlen < SIN6_LEN_RFC2133)
4622 return -EINVAL;
4623 addr6 = (struct sockaddr_in6 *)address;
4624 snum = ntohs(addr6->sin6_port);
4625 addrp = (char *)&addr6->sin6_addr.s6_addr;
4626 break;
4627 default:
4628 goto err_af;
4629 }
4630
4631 ad.type = LSM_AUDIT_DATA_NET;
4632 ad.u.net = &net;
4633 ad.u.net->sport = htons(snum);
4634 ad.u.net->family = family_sa;
4635
4636 if (snum) {
4637 int low, high;
4638
4639 inet_get_local_port_range(sock_net(sk), &low, &high);
4640
4641 if (inet_port_requires_bind_service(sock_net(sk), snum) ||
4642 snum < low || snum > high) {
4643 err = sel_netport_sid(sk->sk_protocol,
4644 snum, &sid);
4645 if (err)
4646 goto out;
4647 err = avc_has_perm(&selinux_state,
4648 sksec->sid, sid,
4649 sksec->sclass,
4650 SOCKET__NAME_BIND, &ad);
4651 if (err)
4652 goto out;
4653 }
4654 }
4655
4656 switch (sksec->sclass) {
4657 case SECCLASS_TCP_SOCKET:
4658 node_perm = TCP_SOCKET__NODE_BIND;
4659 break;
4660
4661 case SECCLASS_UDP_SOCKET:
4662 node_perm = UDP_SOCKET__NODE_BIND;
4663 break;
4664
4665 case SECCLASS_DCCP_SOCKET:
4666 node_perm = DCCP_SOCKET__NODE_BIND;
4667 break;
4668
4669 case SECCLASS_SCTP_SOCKET:
4670 node_perm = SCTP_SOCKET__NODE_BIND;
4671 break;
4672
4673 default:
4674 node_perm = RAWIP_SOCKET__NODE_BIND;
4675 break;
4676 }
4677
4678 err = sel_netnode_sid(addrp, family_sa, &sid);
4679 if (err)
4680 goto out;
4681
4682 if (family_sa == AF_INET)
4683 ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
4684 else
4685 ad.u.net->v6info.saddr = addr6->sin6_addr;
4686
4687 err = avc_has_perm(&selinux_state,
4688 sksec->sid, sid,
4689 sksec->sclass, node_perm, &ad);
4690 if (err)
4691 goto out;
4692 }
4693 out:
4694 return err;
4695 err_af:
4696 /* Note that SCTP services expect -EINVAL, others -EAFNOSUPPORT. */
4697 if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4698 return -EINVAL;
4699 return -EAFNOSUPPORT;
4700 }
4701
4702 /* This supports connect(2) and SCTP connect services such as sctp_connectx(3)
4703 * and sctp_sendmsg(3) as described in Documentation/security/SCTP.rst
4704 */
selinux_socket_connect_helper(struct socket * sock,struct sockaddr * address,int addrlen)4705 static int selinux_socket_connect_helper(struct socket *sock,
4706 struct sockaddr *address, int addrlen)
4707 {
4708 struct sock *sk = sock->sk;
4709 struct sk_security_struct *sksec = sk->sk_security;
4710 int err;
4711
4712 err = sock_has_perm(sk, SOCKET__CONNECT);
4713 if (err)
4714 return err;
4715 if (addrlen < offsetofend(struct sockaddr, sa_family))
4716 return -EINVAL;
4717
4718 /* connect(AF_UNSPEC) has special handling, as it is a documented
4719 * way to disconnect the socket
4720 */
4721 if (address->sa_family == AF_UNSPEC)
4722 return 0;
4723
4724 /*
4725 * If a TCP, DCCP or SCTP socket, check name_connect permission
4726 * for the port.
4727 */
4728 if (sksec->sclass == SECCLASS_TCP_SOCKET ||
4729 sksec->sclass == SECCLASS_DCCP_SOCKET ||
4730 sksec->sclass == SECCLASS_SCTP_SOCKET) {
4731 struct common_audit_data ad;
4732 struct lsm_network_audit net = {0,};
4733 struct sockaddr_in *addr4 = NULL;
4734 struct sockaddr_in6 *addr6 = NULL;
4735 unsigned short snum;
4736 u32 sid, perm;
4737
4738 /* sctp_connectx(3) calls via selinux_sctp_bind_connect()
4739 * that validates multiple connect addresses. Because of this
4740 * need to check address->sa_family as it is possible to have
4741 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
4742 */
4743 switch (address->sa_family) {
4744 case AF_INET:
4745 addr4 = (struct sockaddr_in *)address;
4746 if (addrlen < sizeof(struct sockaddr_in))
4747 return -EINVAL;
4748 snum = ntohs(addr4->sin_port);
4749 break;
4750 case AF_INET6:
4751 addr6 = (struct sockaddr_in6 *)address;
4752 if (addrlen < SIN6_LEN_RFC2133)
4753 return -EINVAL;
4754 snum = ntohs(addr6->sin6_port);
4755 break;
4756 default:
4757 /* Note that SCTP services expect -EINVAL, whereas
4758 * others expect -EAFNOSUPPORT.
4759 */
4760 if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4761 return -EINVAL;
4762 else
4763 return -EAFNOSUPPORT;
4764 }
4765
4766 err = sel_netport_sid(sk->sk_protocol, snum, &sid);
4767 if (err)
4768 return err;
4769
4770 switch (sksec->sclass) {
4771 case SECCLASS_TCP_SOCKET:
4772 perm = TCP_SOCKET__NAME_CONNECT;
4773 break;
4774 case SECCLASS_DCCP_SOCKET:
4775 perm = DCCP_SOCKET__NAME_CONNECT;
4776 break;
4777 case SECCLASS_SCTP_SOCKET:
4778 perm = SCTP_SOCKET__NAME_CONNECT;
4779 break;
4780 }
4781
4782 ad.type = LSM_AUDIT_DATA_NET;
4783 ad.u.net = &net;
4784 ad.u.net->dport = htons(snum);
4785 ad.u.net->family = address->sa_family;
4786 err = avc_has_perm(&selinux_state,
4787 sksec->sid, sid, sksec->sclass, perm, &ad);
4788 if (err)
4789 return err;
4790 }
4791
4792 return 0;
4793 }
4794
4795 /* Supports connect(2), see comments in selinux_socket_connect_helper() */
selinux_socket_connect(struct socket * sock,struct sockaddr * address,int addrlen)4796 static int selinux_socket_connect(struct socket *sock,
4797 struct sockaddr *address, int addrlen)
4798 {
4799 int err;
4800 struct sock *sk = sock->sk;
4801
4802 err = selinux_socket_connect_helper(sock, address, addrlen);
4803 if (err)
4804 return err;
4805
4806 return selinux_netlbl_socket_connect(sk, address);
4807 }
4808
selinux_socket_listen(struct socket * sock,int backlog)4809 static int selinux_socket_listen(struct socket *sock, int backlog)
4810 {
4811 return sock_has_perm(sock->sk, SOCKET__LISTEN);
4812 }
4813
selinux_socket_accept(struct socket * sock,struct socket * newsock)4814 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
4815 {
4816 int err;
4817 struct inode_security_struct *isec;
4818 struct inode_security_struct *newisec;
4819 u16 sclass;
4820 u32 sid;
4821
4822 err = sock_has_perm(sock->sk, SOCKET__ACCEPT);
4823 if (err)
4824 return err;
4825
4826 isec = inode_security_novalidate(SOCK_INODE(sock));
4827 spin_lock(&isec->lock);
4828 sclass = isec->sclass;
4829 sid = isec->sid;
4830 spin_unlock(&isec->lock);
4831
4832 newisec = inode_security_novalidate(SOCK_INODE(newsock));
4833 newisec->sclass = sclass;
4834 newisec->sid = sid;
4835 newisec->initialized = LABEL_INITIALIZED;
4836
4837 return 0;
4838 }
4839
selinux_socket_sendmsg(struct socket * sock,struct msghdr * msg,int size)4840 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4841 int size)
4842 {
4843 return sock_has_perm(sock->sk, SOCKET__WRITE);
4844 }
4845
selinux_socket_recvmsg(struct socket * sock,struct msghdr * msg,int size,int flags)4846 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
4847 int size, int flags)
4848 {
4849 return sock_has_perm(sock->sk, SOCKET__READ);
4850 }
4851
selinux_socket_getsockname(struct socket * sock)4852 static int selinux_socket_getsockname(struct socket *sock)
4853 {
4854 return sock_has_perm(sock->sk, SOCKET__GETATTR);
4855 }
4856
selinux_socket_getpeername(struct socket * sock)4857 static int selinux_socket_getpeername(struct socket *sock)
4858 {
4859 return sock_has_perm(sock->sk, SOCKET__GETATTR);
4860 }
4861
selinux_socket_setsockopt(struct socket * sock,int level,int optname)4862 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
4863 {
4864 int err;
4865
4866 err = sock_has_perm(sock->sk, SOCKET__SETOPT);
4867 if (err)
4868 return err;
4869
4870 return selinux_netlbl_socket_setsockopt(sock, level, optname);
4871 }
4872
selinux_socket_getsockopt(struct socket * sock,int level,int optname)4873 static int selinux_socket_getsockopt(struct socket *sock, int level,
4874 int optname)
4875 {
4876 return sock_has_perm(sock->sk, SOCKET__GETOPT);
4877 }
4878
selinux_socket_shutdown(struct socket * sock,int how)4879 static int selinux_socket_shutdown(struct socket *sock, int how)
4880 {
4881 return sock_has_perm(sock->sk, SOCKET__SHUTDOWN);
4882 }
4883
selinux_socket_unix_stream_connect(struct sock * sock,struct sock * other,struct sock * newsk)4884 static int selinux_socket_unix_stream_connect(struct sock *sock,
4885 struct sock *other,
4886 struct sock *newsk)
4887 {
4888 struct sk_security_struct *sksec_sock = sock->sk_security;
4889 struct sk_security_struct *sksec_other = other->sk_security;
4890 struct sk_security_struct *sksec_new = newsk->sk_security;
4891 struct common_audit_data ad;
4892 struct lsm_network_audit net = {0,};
4893 int err;
4894
4895 ad.type = LSM_AUDIT_DATA_NET;
4896 ad.u.net = &net;
4897 ad.u.net->sk = other;
4898
4899 err = avc_has_perm(&selinux_state,
4900 sksec_sock->sid, sksec_other->sid,
4901 sksec_other->sclass,
4902 UNIX_STREAM_SOCKET__CONNECTTO, &ad);
4903 if (err)
4904 return err;
4905
4906 /* server child socket */
4907 sksec_new->peer_sid = sksec_sock->sid;
4908 err = security_sid_mls_copy(&selinux_state, sksec_other->sid,
4909 sksec_sock->sid, &sksec_new->sid);
4910 if (err)
4911 return err;
4912
4913 /* connecting socket */
4914 sksec_sock->peer_sid = sksec_new->sid;
4915
4916 return 0;
4917 }
4918
selinux_socket_unix_may_send(struct socket * sock,struct socket * other)4919 static int selinux_socket_unix_may_send(struct socket *sock,
4920 struct socket *other)
4921 {
4922 struct sk_security_struct *ssec = sock->sk->sk_security;
4923 struct sk_security_struct *osec = other->sk->sk_security;
4924 struct common_audit_data ad;
4925 struct lsm_network_audit net = {0,};
4926
4927 ad.type = LSM_AUDIT_DATA_NET;
4928 ad.u.net = &net;
4929 ad.u.net->sk = other->sk;
4930
4931 return avc_has_perm(&selinux_state,
4932 ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
4933 &ad);
4934 }
4935
selinux_inet_sys_rcv_skb(struct net * ns,int ifindex,char * addrp,u16 family,u32 peer_sid,struct common_audit_data * ad)4936 static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
4937 char *addrp, u16 family, u32 peer_sid,
4938 struct common_audit_data *ad)
4939 {
4940 int err;
4941 u32 if_sid;
4942 u32 node_sid;
4943
4944 err = sel_netif_sid(ns, ifindex, &if_sid);
4945 if (err)
4946 return err;
4947 err = avc_has_perm(&selinux_state,
4948 peer_sid, if_sid,
4949 SECCLASS_NETIF, NETIF__INGRESS, ad);
4950 if (err)
4951 return err;
4952
4953 err = sel_netnode_sid(addrp, family, &node_sid);
4954 if (err)
4955 return err;
4956 return avc_has_perm(&selinux_state,
4957 peer_sid, node_sid,
4958 SECCLASS_NODE, NODE__RECVFROM, ad);
4959 }
4960
selinux_sock_rcv_skb_compat(struct sock * sk,struct sk_buff * skb,u16 family)4961 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4962 u16 family)
4963 {
4964 int err = 0;
4965 struct sk_security_struct *sksec = sk->sk_security;
4966 u32 sk_sid = sksec->sid;
4967 struct common_audit_data ad;
4968 struct lsm_network_audit net = {0,};
4969 char *addrp;
4970
4971 ad.type = LSM_AUDIT_DATA_NET;
4972 ad.u.net = &net;
4973 ad.u.net->netif = skb->skb_iif;
4974 ad.u.net->family = family;
4975 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4976 if (err)
4977 return err;
4978
4979 if (selinux_secmark_enabled()) {
4980 err = avc_has_perm(&selinux_state,
4981 sk_sid, skb->secmark, SECCLASS_PACKET,
4982 PACKET__RECV, &ad);
4983 if (err)
4984 return err;
4985 }
4986
4987 err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
4988 if (err)
4989 return err;
4990 err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4991
4992 return err;
4993 }
4994
selinux_socket_sock_rcv_skb(struct sock * sk,struct sk_buff * skb)4995 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
4996 {
4997 int err;
4998 struct sk_security_struct *sksec = sk->sk_security;
4999 u16 family = sk->sk_family;
5000 u32 sk_sid = sksec->sid;
5001 struct common_audit_data ad;
5002 struct lsm_network_audit net = {0,};
5003 char *addrp;
5004 u8 secmark_active;
5005 u8 peerlbl_active;
5006
5007 if (family != PF_INET && family != PF_INET6)
5008 return 0;
5009
5010 /* Handle mapped IPv4 packets arriving via IPv6 sockets */
5011 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5012 family = PF_INET;
5013
5014 /* If any sort of compatibility mode is enabled then handoff processing
5015 * to the selinux_sock_rcv_skb_compat() function to deal with the
5016 * special handling. We do this in an attempt to keep this function
5017 * as fast and as clean as possible. */
5018 if (!selinux_policycap_netpeer())
5019 return selinux_sock_rcv_skb_compat(sk, skb, family);
5020
5021 secmark_active = selinux_secmark_enabled();
5022 peerlbl_active = selinux_peerlbl_enabled();
5023 if (!secmark_active && !peerlbl_active)
5024 return 0;
5025
5026 ad.type = LSM_AUDIT_DATA_NET;
5027 ad.u.net = &net;
5028 ad.u.net->netif = skb->skb_iif;
5029 ad.u.net->family = family;
5030 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
5031 if (err)
5032 return err;
5033
5034 if (peerlbl_active) {
5035 u32 peer_sid;
5036
5037 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
5038 if (err)
5039 return err;
5040 err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
5041 addrp, family, peer_sid, &ad);
5042 if (err) {
5043 selinux_netlbl_err(skb, family, err, 0);
5044 return err;
5045 }
5046 err = avc_has_perm(&selinux_state,
5047 sk_sid, peer_sid, SECCLASS_PEER,
5048 PEER__RECV, &ad);
5049 if (err) {
5050 selinux_netlbl_err(skb, family, err, 0);
5051 return err;
5052 }
5053 }
5054
5055 if (secmark_active) {
5056 err = avc_has_perm(&selinux_state,
5057 sk_sid, skb->secmark, SECCLASS_PACKET,
5058 PACKET__RECV, &ad);
5059 if (err)
5060 return err;
5061 }
5062
5063 return err;
5064 }
5065
selinux_socket_getpeersec_stream(struct socket * sock,char __user * optval,int __user * optlen,unsigned len)5066 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
5067 int __user *optlen, unsigned len)
5068 {
5069 int err = 0;
5070 char *scontext;
5071 u32 scontext_len;
5072 struct sk_security_struct *sksec = sock->sk->sk_security;
5073 u32 peer_sid = SECSID_NULL;
5074
5075 if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
5076 sksec->sclass == SECCLASS_TCP_SOCKET ||
5077 sksec->sclass == SECCLASS_SCTP_SOCKET)
5078 peer_sid = sksec->peer_sid;
5079 if (peer_sid == SECSID_NULL)
5080 return -ENOPROTOOPT;
5081
5082 err = security_sid_to_context(&selinux_state, peer_sid, &scontext,
5083 &scontext_len);
5084 if (err)
5085 return err;
5086
5087 if (scontext_len > len) {
5088 err = -ERANGE;
5089 goto out_len;
5090 }
5091
5092 if (copy_to_user(optval, scontext, scontext_len))
5093 err = -EFAULT;
5094
5095 out_len:
5096 if (put_user(scontext_len, optlen))
5097 err = -EFAULT;
5098 kfree(scontext);
5099 return err;
5100 }
5101
selinux_socket_getpeersec_dgram(struct socket * sock,struct sk_buff * skb,u32 * secid)5102 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
5103 {
5104 u32 peer_secid = SECSID_NULL;
5105 u16 family;
5106 struct inode_security_struct *isec;
5107
5108 if (skb && skb->protocol == htons(ETH_P_IP))
5109 family = PF_INET;
5110 else if (skb && skb->protocol == htons(ETH_P_IPV6))
5111 family = PF_INET6;
5112 else if (sock)
5113 family = sock->sk->sk_family;
5114 else
5115 goto out;
5116
5117 if (sock && family == PF_UNIX) {
5118 isec = inode_security_novalidate(SOCK_INODE(sock));
5119 peer_secid = isec->sid;
5120 } else if (skb)
5121 selinux_skb_peerlbl_sid(skb, family, &peer_secid);
5122
5123 out:
5124 *secid = peer_secid;
5125 if (peer_secid == SECSID_NULL)
5126 return -EINVAL;
5127 return 0;
5128 }
5129
selinux_sk_alloc_security(struct sock * sk,int family,gfp_t priority)5130 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
5131 {
5132 struct sk_security_struct *sksec;
5133
5134 sksec = kzalloc(sizeof(*sksec), priority);
5135 if (!sksec)
5136 return -ENOMEM;
5137
5138 sksec->peer_sid = SECINITSID_UNLABELED;
5139 sksec->sid = SECINITSID_UNLABELED;
5140 sksec->sclass = SECCLASS_SOCKET;
5141 selinux_netlbl_sk_security_reset(sksec);
5142 sk->sk_security = sksec;
5143
5144 return 0;
5145 }
5146
selinux_sk_free_security(struct sock * sk)5147 static void selinux_sk_free_security(struct sock *sk)
5148 {
5149 struct sk_security_struct *sksec = sk->sk_security;
5150
5151 sk->sk_security = NULL;
5152 selinux_netlbl_sk_security_free(sksec);
5153 kfree(sksec);
5154 }
5155
selinux_sk_clone_security(const struct sock * sk,struct sock * newsk)5156 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
5157 {
5158 struct sk_security_struct *sksec = sk->sk_security;
5159 struct sk_security_struct *newsksec = newsk->sk_security;
5160
5161 newsksec->sid = sksec->sid;
5162 newsksec->peer_sid = sksec->peer_sid;
5163 newsksec->sclass = sksec->sclass;
5164
5165 selinux_netlbl_sk_security_reset(newsksec);
5166 }
5167
selinux_sk_getsecid(struct sock * sk,u32 * secid)5168 static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
5169 {
5170 if (!sk)
5171 *secid = SECINITSID_ANY_SOCKET;
5172 else {
5173 struct sk_security_struct *sksec = sk->sk_security;
5174
5175 *secid = sksec->sid;
5176 }
5177 }
5178
selinux_sock_graft(struct sock * sk,struct socket * parent)5179 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
5180 {
5181 struct inode_security_struct *isec =
5182 inode_security_novalidate(SOCK_INODE(parent));
5183 struct sk_security_struct *sksec = sk->sk_security;
5184
5185 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
5186 sk->sk_family == PF_UNIX)
5187 isec->sid = sksec->sid;
5188 sksec->sclass = isec->sclass;
5189 }
5190
5191 /* Called whenever SCTP receives an INIT chunk. This happens when an incoming
5192 * connect(2), sctp_connectx(3) or sctp_sendmsg(3) (with no association
5193 * already present).
5194 */
selinux_sctp_assoc_request(struct sctp_endpoint * ep,struct sk_buff * skb)5195 static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
5196 struct sk_buff *skb)
5197 {
5198 struct sk_security_struct *sksec = ep->base.sk->sk_security;
5199 struct common_audit_data ad;
5200 struct lsm_network_audit net = {0,};
5201 u8 peerlbl_active;
5202 u32 peer_sid = SECINITSID_UNLABELED;
5203 u32 conn_sid;
5204 int err = 0;
5205
5206 if (!selinux_policycap_extsockclass())
5207 return 0;
5208
5209 peerlbl_active = selinux_peerlbl_enabled();
5210
5211 if (peerlbl_active) {
5212 /* This will return peer_sid = SECSID_NULL if there are
5213 * no peer labels, see security_net_peersid_resolve().
5214 */
5215 err = selinux_skb_peerlbl_sid(skb, ep->base.sk->sk_family,
5216 &peer_sid);
5217 if (err)
5218 return err;
5219
5220 if (peer_sid == SECSID_NULL)
5221 peer_sid = SECINITSID_UNLABELED;
5222 }
5223
5224 if (sksec->sctp_assoc_state == SCTP_ASSOC_UNSET) {
5225 sksec->sctp_assoc_state = SCTP_ASSOC_SET;
5226
5227 /* Here as first association on socket. As the peer SID
5228 * was allowed by peer recv (and the netif/node checks),
5229 * then it is approved by policy and used as the primary
5230 * peer SID for getpeercon(3).
5231 */
5232 sksec->peer_sid = peer_sid;
5233 } else if (sksec->peer_sid != peer_sid) {
5234 /* Other association peer SIDs are checked to enforce
5235 * consistency among the peer SIDs.
5236 */
5237 ad.type = LSM_AUDIT_DATA_NET;
5238 ad.u.net = &net;
5239 ad.u.net->sk = ep->base.sk;
5240 err = avc_has_perm(&selinux_state,
5241 sksec->peer_sid, peer_sid, sksec->sclass,
5242 SCTP_SOCKET__ASSOCIATION, &ad);
5243 if (err)
5244 return err;
5245 }
5246
5247 /* Compute the MLS component for the connection and store
5248 * the information in ep. This will be used by SCTP TCP type
5249 * sockets and peeled off connections as they cause a new
5250 * socket to be generated. selinux_sctp_sk_clone() will then
5251 * plug this into the new socket.
5252 */
5253 err = selinux_conn_sid(sksec->sid, peer_sid, &conn_sid);
5254 if (err)
5255 return err;
5256
5257 ep->secid = conn_sid;
5258 ep->peer_secid = peer_sid;
5259
5260 /* Set any NetLabel labels including CIPSO/CALIPSO options. */
5261 return selinux_netlbl_sctp_assoc_request(ep, skb);
5262 }
5263
5264 /* Check if sctp IPv4/IPv6 addresses are valid for binding or connecting
5265 * based on their @optname.
5266 */
selinux_sctp_bind_connect(struct sock * sk,int optname,struct sockaddr * address,int addrlen)5267 static int selinux_sctp_bind_connect(struct sock *sk, int optname,
5268 struct sockaddr *address,
5269 int addrlen)
5270 {
5271 int len, err = 0, walk_size = 0;
5272 void *addr_buf;
5273 struct sockaddr *addr;
5274 struct socket *sock;
5275
5276 if (!selinux_policycap_extsockclass())
5277 return 0;
5278
5279 /* Process one or more addresses that may be IPv4 or IPv6 */
5280 sock = sk->sk_socket;
5281 addr_buf = address;
5282
5283 while (walk_size < addrlen) {
5284 if (walk_size + sizeof(sa_family_t) > addrlen)
5285 return -EINVAL;
5286
5287 addr = addr_buf;
5288 switch (addr->sa_family) {
5289 case AF_UNSPEC:
5290 case AF_INET:
5291 len = sizeof(struct sockaddr_in);
5292 break;
5293 case AF_INET6:
5294 len = sizeof(struct sockaddr_in6);
5295 break;
5296 default:
5297 return -EINVAL;
5298 }
5299
5300 if (walk_size + len > addrlen)
5301 return -EINVAL;
5302
5303 err = -EINVAL;
5304 switch (optname) {
5305 /* Bind checks */
5306 case SCTP_PRIMARY_ADDR:
5307 case SCTP_SET_PEER_PRIMARY_ADDR:
5308 case SCTP_SOCKOPT_BINDX_ADD:
5309 err = selinux_socket_bind(sock, addr, len);
5310 break;
5311 /* Connect checks */
5312 case SCTP_SOCKOPT_CONNECTX:
5313 case SCTP_PARAM_SET_PRIMARY:
5314 case SCTP_PARAM_ADD_IP:
5315 case SCTP_SENDMSG_CONNECT:
5316 err = selinux_socket_connect_helper(sock, addr, len);
5317 if (err)
5318 return err;
5319
5320 /* As selinux_sctp_bind_connect() is called by the
5321 * SCTP protocol layer, the socket is already locked,
5322 * therefore selinux_netlbl_socket_connect_locked()
5323 * is called here. The situations handled are:
5324 * sctp_connectx(3), sctp_sendmsg(3), sendmsg(2),
5325 * whenever a new IP address is added or when a new
5326 * primary address is selected.
5327 * Note that an SCTP connect(2) call happens before
5328 * the SCTP protocol layer and is handled via
5329 * selinux_socket_connect().
5330 */
5331 err = selinux_netlbl_socket_connect_locked(sk, addr);
5332 break;
5333 }
5334
5335 if (err)
5336 return err;
5337
5338 addr_buf += len;
5339 walk_size += len;
5340 }
5341
5342 return 0;
5343 }
5344
5345 /* Called whenever a new socket is created by accept(2) or sctp_peeloff(3). */
selinux_sctp_sk_clone(struct sctp_endpoint * ep,struct sock * sk,struct sock * newsk)5346 static void selinux_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
5347 struct sock *newsk)
5348 {
5349 struct sk_security_struct *sksec = sk->sk_security;
5350 struct sk_security_struct *newsksec = newsk->sk_security;
5351
5352 /* If policy does not support SECCLASS_SCTP_SOCKET then call
5353 * the non-sctp clone version.
5354 */
5355 if (!selinux_policycap_extsockclass())
5356 return selinux_sk_clone_security(sk, newsk);
5357
5358 newsksec->sid = ep->secid;
5359 newsksec->peer_sid = ep->peer_secid;
5360 newsksec->sclass = sksec->sclass;
5361 selinux_netlbl_sctp_sk_clone(sk, newsk);
5362 }
5363
selinux_inet_conn_request(struct sock * sk,struct sk_buff * skb,struct request_sock * req)5364 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
5365 struct request_sock *req)
5366 {
5367 struct sk_security_struct *sksec = sk->sk_security;
5368 int err;
5369 u16 family = req->rsk_ops->family;
5370 u32 connsid;
5371 u32 peersid;
5372
5373 err = selinux_skb_peerlbl_sid(skb, family, &peersid);
5374 if (err)
5375 return err;
5376 err = selinux_conn_sid(sksec->sid, peersid, &connsid);
5377 if (err)
5378 return err;
5379 req->secid = connsid;
5380 req->peer_secid = peersid;
5381
5382 return selinux_netlbl_inet_conn_request(req, family);
5383 }
5384
selinux_inet_csk_clone(struct sock * newsk,const struct request_sock * req)5385 static void selinux_inet_csk_clone(struct sock *newsk,
5386 const struct request_sock *req)
5387 {
5388 struct sk_security_struct *newsksec = newsk->sk_security;
5389
5390 newsksec->sid = req->secid;
5391 newsksec->peer_sid = req->peer_secid;
5392 /* NOTE: Ideally, we should also get the isec->sid for the
5393 new socket in sync, but we don't have the isec available yet.
5394 So we will wait until sock_graft to do it, by which
5395 time it will have been created and available. */
5396
5397 /* We don't need to take any sort of lock here as we are the only
5398 * thread with access to newsksec */
5399 selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
5400 }
5401
selinux_inet_conn_established(struct sock * sk,struct sk_buff * skb)5402 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
5403 {
5404 u16 family = sk->sk_family;
5405 struct sk_security_struct *sksec = sk->sk_security;
5406
5407 /* handle mapped IPv4 packets arriving via IPv6 sockets */
5408 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5409 family = PF_INET;
5410
5411 selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
5412 }
5413
selinux_secmark_relabel_packet(u32 sid)5414 static int selinux_secmark_relabel_packet(u32 sid)
5415 {
5416 const struct task_security_struct *__tsec;
5417 u32 tsid;
5418
5419 __tsec = selinux_cred(current_cred());
5420 tsid = __tsec->sid;
5421
5422 return avc_has_perm(&selinux_state,
5423 tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO,
5424 NULL);
5425 }
5426
selinux_secmark_refcount_inc(void)5427 static void selinux_secmark_refcount_inc(void)
5428 {
5429 atomic_inc(&selinux_secmark_refcount);
5430 }
5431
selinux_secmark_refcount_dec(void)5432 static void selinux_secmark_refcount_dec(void)
5433 {
5434 atomic_dec(&selinux_secmark_refcount);
5435 }
5436
selinux_req_classify_flow(const struct request_sock * req,struct flowi * fl)5437 static void selinux_req_classify_flow(const struct request_sock *req,
5438 struct flowi *fl)
5439 {
5440 fl->flowi_secid = req->secid;
5441 }
5442
selinux_tun_dev_alloc_security(void ** security)5443 static int selinux_tun_dev_alloc_security(void **security)
5444 {
5445 struct tun_security_struct *tunsec;
5446
5447 tunsec = kzalloc(sizeof(*tunsec), GFP_KERNEL);
5448 if (!tunsec)
5449 return -ENOMEM;
5450 tunsec->sid = current_sid();
5451
5452 *security = tunsec;
5453 return 0;
5454 }
5455
selinux_tun_dev_free_security(void * security)5456 static void selinux_tun_dev_free_security(void *security)
5457 {
5458 kfree(security);
5459 }
5460
selinux_tun_dev_create(void)5461 static int selinux_tun_dev_create(void)
5462 {
5463 u32 sid = current_sid();
5464
5465 /* we aren't taking into account the "sockcreate" SID since the socket
5466 * that is being created here is not a socket in the traditional sense,
5467 * instead it is a private sock, accessible only to the kernel, and
5468 * representing a wide range of network traffic spanning multiple
5469 * connections unlike traditional sockets - check the TUN driver to
5470 * get a better understanding of why this socket is special */
5471
5472 return avc_has_perm(&selinux_state,
5473 sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
5474 NULL);
5475 }
5476
selinux_tun_dev_attach_queue(void * security)5477 static int selinux_tun_dev_attach_queue(void *security)
5478 {
5479 struct tun_security_struct *tunsec = security;
5480
5481 return avc_has_perm(&selinux_state,
5482 current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET,
5483 TUN_SOCKET__ATTACH_QUEUE, NULL);
5484 }
5485
selinux_tun_dev_attach(struct sock * sk,void * security)5486 static int selinux_tun_dev_attach(struct sock *sk, void *security)
5487 {
5488 struct tun_security_struct *tunsec = security;
5489 struct sk_security_struct *sksec = sk->sk_security;
5490
5491 /* we don't currently perform any NetLabel based labeling here and it
5492 * isn't clear that we would want to do so anyway; while we could apply
5493 * labeling without the support of the TUN user the resulting labeled
5494 * traffic from the other end of the connection would almost certainly
5495 * cause confusion to the TUN user that had no idea network labeling
5496 * protocols were being used */
5497
5498 sksec->sid = tunsec->sid;
5499 sksec->sclass = SECCLASS_TUN_SOCKET;
5500
5501 return 0;
5502 }
5503
selinux_tun_dev_open(void * security)5504 static int selinux_tun_dev_open(void *security)
5505 {
5506 struct tun_security_struct *tunsec = security;
5507 u32 sid = current_sid();
5508 int err;
5509
5510 err = avc_has_perm(&selinux_state,
5511 sid, tunsec->sid, SECCLASS_TUN_SOCKET,
5512 TUN_SOCKET__RELABELFROM, NULL);
5513 if (err)
5514 return err;
5515 err = avc_has_perm(&selinux_state,
5516 sid, sid, SECCLASS_TUN_SOCKET,
5517 TUN_SOCKET__RELABELTO, NULL);
5518 if (err)
5519 return err;
5520 tunsec->sid = sid;
5521
5522 return 0;
5523 }
5524
5525 #ifdef CONFIG_NETFILTER
5526
selinux_ip_forward(struct sk_buff * skb,const struct net_device * indev,u16 family)5527 static unsigned int selinux_ip_forward(struct sk_buff *skb,
5528 const struct net_device *indev,
5529 u16 family)
5530 {
5531 int err;
5532 char *addrp;
5533 u32 peer_sid;
5534 struct common_audit_data ad;
5535 struct lsm_network_audit net = {0,};
5536 u8 secmark_active;
5537 u8 netlbl_active;
5538 u8 peerlbl_active;
5539
5540 if (!selinux_policycap_netpeer())
5541 return NF_ACCEPT;
5542
5543 secmark_active = selinux_secmark_enabled();
5544 netlbl_active = netlbl_enabled();
5545 peerlbl_active = selinux_peerlbl_enabled();
5546 if (!secmark_active && !peerlbl_active)
5547 return NF_ACCEPT;
5548
5549 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
5550 return NF_DROP;
5551
5552 ad.type = LSM_AUDIT_DATA_NET;
5553 ad.u.net = &net;
5554 ad.u.net->netif = indev->ifindex;
5555 ad.u.net->family = family;
5556 if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
5557 return NF_DROP;
5558
5559 if (peerlbl_active) {
5560 err = selinux_inet_sys_rcv_skb(dev_net(indev), indev->ifindex,
5561 addrp, family, peer_sid, &ad);
5562 if (err) {
5563 selinux_netlbl_err(skb, family, err, 1);
5564 return NF_DROP;
5565 }
5566 }
5567
5568 if (secmark_active)
5569 if (avc_has_perm(&selinux_state,
5570 peer_sid, skb->secmark,
5571 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
5572 return NF_DROP;
5573
5574 if (netlbl_active)
5575 /* we do this in the FORWARD path and not the POST_ROUTING
5576 * path because we want to make sure we apply the necessary
5577 * labeling before IPsec is applied so we can leverage AH
5578 * protection */
5579 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
5580 return NF_DROP;
5581
5582 return NF_ACCEPT;
5583 }
5584
selinux_ipv4_forward(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5585 static unsigned int selinux_ipv4_forward(void *priv,
5586 struct sk_buff *skb,
5587 const struct nf_hook_state *state)
5588 {
5589 return selinux_ip_forward(skb, state->in, PF_INET);
5590 }
5591
5592 #if IS_ENABLED(CONFIG_IPV6)
selinux_ipv6_forward(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5593 static unsigned int selinux_ipv6_forward(void *priv,
5594 struct sk_buff *skb,
5595 const struct nf_hook_state *state)
5596 {
5597 return selinux_ip_forward(skb, state->in, PF_INET6);
5598 }
5599 #endif /* IPV6 */
5600
selinux_ip_output(struct sk_buff * skb,u16 family)5601 static unsigned int selinux_ip_output(struct sk_buff *skb,
5602 u16 family)
5603 {
5604 struct sock *sk;
5605 u32 sid;
5606
5607 if (!netlbl_enabled())
5608 return NF_ACCEPT;
5609
5610 /* we do this in the LOCAL_OUT path and not the POST_ROUTING path
5611 * because we want to make sure we apply the necessary labeling
5612 * before IPsec is applied so we can leverage AH protection */
5613 sk = skb->sk;
5614 if (sk) {
5615 struct sk_security_struct *sksec;
5616
5617 if (sk_listener(sk))
5618 /* if the socket is the listening state then this
5619 * packet is a SYN-ACK packet which means it needs to
5620 * be labeled based on the connection/request_sock and
5621 * not the parent socket. unfortunately, we can't
5622 * lookup the request_sock yet as it isn't queued on
5623 * the parent socket until after the SYN-ACK is sent.
5624 * the "solution" is to simply pass the packet as-is
5625 * as any IP option based labeling should be copied
5626 * from the initial connection request (in the IP
5627 * layer). it is far from ideal, but until we get a
5628 * security label in the packet itself this is the
5629 * best we can do. */
5630 return NF_ACCEPT;
5631
5632 /* standard practice, label using the parent socket */
5633 sksec = sk->sk_security;
5634 sid = sksec->sid;
5635 } else
5636 sid = SECINITSID_KERNEL;
5637 if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
5638 return NF_DROP;
5639
5640 return NF_ACCEPT;
5641 }
5642
selinux_ipv4_output(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5643 static unsigned int selinux_ipv4_output(void *priv,
5644 struct sk_buff *skb,
5645 const struct nf_hook_state *state)
5646 {
5647 return selinux_ip_output(skb, PF_INET);
5648 }
5649
5650 #if IS_ENABLED(CONFIG_IPV6)
selinux_ipv6_output(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5651 static unsigned int selinux_ipv6_output(void *priv,
5652 struct sk_buff *skb,
5653 const struct nf_hook_state *state)
5654 {
5655 return selinux_ip_output(skb, PF_INET6);
5656 }
5657 #endif /* IPV6 */
5658
selinux_ip_postroute_compat(struct sk_buff * skb,int ifindex,u16 family)5659 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
5660 int ifindex,
5661 u16 family)
5662 {
5663 struct sock *sk = skb_to_full_sk(skb);
5664 struct sk_security_struct *sksec;
5665 struct common_audit_data ad;
5666 struct lsm_network_audit net = {0,};
5667 char *addrp;
5668 u8 proto;
5669
5670 if (sk == NULL)
5671 return NF_ACCEPT;
5672 sksec = sk->sk_security;
5673
5674 ad.type = LSM_AUDIT_DATA_NET;
5675 ad.u.net = &net;
5676 ad.u.net->netif = ifindex;
5677 ad.u.net->family = family;
5678 if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
5679 return NF_DROP;
5680
5681 if (selinux_secmark_enabled())
5682 if (avc_has_perm(&selinux_state,
5683 sksec->sid, skb->secmark,
5684 SECCLASS_PACKET, PACKET__SEND, &ad))
5685 return NF_DROP_ERR(-ECONNREFUSED);
5686
5687 if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
5688 return NF_DROP_ERR(-ECONNREFUSED);
5689
5690 return NF_ACCEPT;
5691 }
5692
selinux_ip_postroute(struct sk_buff * skb,const struct net_device * outdev,u16 family)5693 static unsigned int selinux_ip_postroute(struct sk_buff *skb,
5694 const struct net_device *outdev,
5695 u16 family)
5696 {
5697 u32 secmark_perm;
5698 u32 peer_sid;
5699 int ifindex = outdev->ifindex;
5700 struct sock *sk;
5701 struct common_audit_data ad;
5702 struct lsm_network_audit net = {0,};
5703 char *addrp;
5704 u8 secmark_active;
5705 u8 peerlbl_active;
5706
5707 /* If any sort of compatibility mode is enabled then handoff processing
5708 * to the selinux_ip_postroute_compat() function to deal with the
5709 * special handling. We do this in an attempt to keep this function
5710 * as fast and as clean as possible. */
5711 if (!selinux_policycap_netpeer())
5712 return selinux_ip_postroute_compat(skb, ifindex, family);
5713
5714 secmark_active = selinux_secmark_enabled();
5715 peerlbl_active = selinux_peerlbl_enabled();
5716 if (!secmark_active && !peerlbl_active)
5717 return NF_ACCEPT;
5718
5719 sk = skb_to_full_sk(skb);
5720
5721 #ifdef CONFIG_XFRM
5722 /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
5723 * packet transformation so allow the packet to pass without any checks
5724 * since we'll have another chance to perform access control checks
5725 * when the packet is on it's final way out.
5726 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
5727 * is NULL, in this case go ahead and apply access control.
5728 * NOTE: if this is a local socket (skb->sk != NULL) that is in the
5729 * TCP listening state we cannot wait until the XFRM processing
5730 * is done as we will miss out on the SA label if we do;
5731 * unfortunately, this means more work, but it is only once per
5732 * connection. */
5733 if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&
5734 !(sk && sk_listener(sk)))
5735 return NF_ACCEPT;
5736 #endif
5737
5738 if (sk == NULL) {
5739 /* Without an associated socket the packet is either coming
5740 * from the kernel or it is being forwarded; check the packet
5741 * to determine which and if the packet is being forwarded
5742 * query the packet directly to determine the security label. */
5743 if (skb->skb_iif) {
5744 secmark_perm = PACKET__FORWARD_OUT;
5745 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
5746 return NF_DROP;
5747 } else {
5748 secmark_perm = PACKET__SEND;
5749 peer_sid = SECINITSID_KERNEL;
5750 }
5751 } else if (sk_listener(sk)) {
5752 /* Locally generated packet but the associated socket is in the
5753 * listening state which means this is a SYN-ACK packet. In
5754 * this particular case the correct security label is assigned
5755 * to the connection/request_sock but unfortunately we can't
5756 * query the request_sock as it isn't queued on the parent
5757 * socket until after the SYN-ACK packet is sent; the only
5758 * viable choice is to regenerate the label like we do in
5759 * selinux_inet_conn_request(). See also selinux_ip_output()
5760 * for similar problems. */
5761 u32 skb_sid;
5762 struct sk_security_struct *sksec;
5763
5764 sksec = sk->sk_security;
5765 if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
5766 return NF_DROP;
5767 /* At this point, if the returned skb peerlbl is SECSID_NULL
5768 * and the packet has been through at least one XFRM
5769 * transformation then we must be dealing with the "final"
5770 * form of labeled IPsec packet; since we've already applied
5771 * all of our access controls on this packet we can safely
5772 * pass the packet. */
5773 if (skb_sid == SECSID_NULL) {
5774 switch (family) {
5775 case PF_INET:
5776 if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
5777 return NF_ACCEPT;
5778 break;
5779 case PF_INET6:
5780 if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
5781 return NF_ACCEPT;
5782 break;
5783 default:
5784 return NF_DROP_ERR(-ECONNREFUSED);
5785 }
5786 }
5787 if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
5788 return NF_DROP;
5789 secmark_perm = PACKET__SEND;
5790 } else {
5791 /* Locally generated packet, fetch the security label from the
5792 * associated socket. */
5793 struct sk_security_struct *sksec = sk->sk_security;
5794 peer_sid = sksec->sid;
5795 secmark_perm = PACKET__SEND;
5796 }
5797
5798 ad.type = LSM_AUDIT_DATA_NET;
5799 ad.u.net = &net;
5800 ad.u.net->netif = ifindex;
5801 ad.u.net->family = family;
5802 if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
5803 return NF_DROP;
5804
5805 if (secmark_active)
5806 if (avc_has_perm(&selinux_state,
5807 peer_sid, skb->secmark,
5808 SECCLASS_PACKET, secmark_perm, &ad))
5809 return NF_DROP_ERR(-ECONNREFUSED);
5810
5811 if (peerlbl_active) {
5812 u32 if_sid;
5813 u32 node_sid;
5814
5815 if (sel_netif_sid(dev_net(outdev), ifindex, &if_sid))
5816 return NF_DROP;
5817 if (avc_has_perm(&selinux_state,
5818 peer_sid, if_sid,
5819 SECCLASS_NETIF, NETIF__EGRESS, &ad))
5820 return NF_DROP_ERR(-ECONNREFUSED);
5821
5822 if (sel_netnode_sid(addrp, family, &node_sid))
5823 return NF_DROP;
5824 if (avc_has_perm(&selinux_state,
5825 peer_sid, node_sid,
5826 SECCLASS_NODE, NODE__SENDTO, &ad))
5827 return NF_DROP_ERR(-ECONNREFUSED);
5828 }
5829
5830 return NF_ACCEPT;
5831 }
5832
selinux_ipv4_postroute(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5833 static unsigned int selinux_ipv4_postroute(void *priv,
5834 struct sk_buff *skb,
5835 const struct nf_hook_state *state)
5836 {
5837 return selinux_ip_postroute(skb, state->out, PF_INET);
5838 }
5839
5840 #if IS_ENABLED(CONFIG_IPV6)
selinux_ipv6_postroute(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5841 static unsigned int selinux_ipv6_postroute(void *priv,
5842 struct sk_buff *skb,
5843 const struct nf_hook_state *state)
5844 {
5845 return selinux_ip_postroute(skb, state->out, PF_INET6);
5846 }
5847 #endif /* IPV6 */
5848
5849 #endif /* CONFIG_NETFILTER */
5850
selinux_netlink_send(struct sock * sk,struct sk_buff * skb)5851 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
5852 {
5853 int rc = 0;
5854 unsigned int msg_len;
5855 unsigned int data_len = skb->len;
5856 unsigned char *data = skb->data;
5857 struct nlmsghdr *nlh;
5858 struct sk_security_struct *sksec = sk->sk_security;
5859 u16 sclass = sksec->sclass;
5860 u32 perm;
5861
5862 while (data_len >= nlmsg_total_size(0)) {
5863 nlh = (struct nlmsghdr *)data;
5864
5865 /* NOTE: the nlmsg_len field isn't reliably set by some netlink
5866 * users which means we can't reject skb's with bogus
5867 * length fields; our solution is to follow what
5868 * netlink_rcv_skb() does and simply skip processing at
5869 * messages with length fields that are clearly junk
5870 */
5871 if (nlh->nlmsg_len < NLMSG_HDRLEN || nlh->nlmsg_len > data_len)
5872 return 0;
5873
5874 rc = selinux_nlmsg_lookup(sclass, nlh->nlmsg_type, &perm);
5875 if (rc == 0) {
5876 rc = sock_has_perm(sk, perm);
5877 if (rc)
5878 return rc;
5879 } else if (rc == -EINVAL) {
5880 /* -EINVAL is a missing msg/perm mapping */
5881 pr_warn_ratelimited("SELinux: unrecognized netlink"
5882 " message: protocol=%hu nlmsg_type=%hu sclass=%s"
5883 " pid=%d comm=%s\n",
5884 sk->sk_protocol, nlh->nlmsg_type,
5885 secclass_map[sclass - 1].name,
5886 task_pid_nr(current), current->comm);
5887 if (enforcing_enabled(&selinux_state) &&
5888 !security_get_allow_unknown(&selinux_state))
5889 return rc;
5890 rc = 0;
5891 } else if (rc == -ENOENT) {
5892 /* -ENOENT is a missing socket/class mapping, ignore */
5893 rc = 0;
5894 } else {
5895 return rc;
5896 }
5897
5898 /* move to the next message after applying netlink padding */
5899 msg_len = NLMSG_ALIGN(nlh->nlmsg_len);
5900 if (msg_len >= data_len)
5901 return 0;
5902 data_len -= msg_len;
5903 data += msg_len;
5904 }
5905
5906 return rc;
5907 }
5908
ipc_init_security(struct ipc_security_struct * isec,u16 sclass)5909 static void ipc_init_security(struct ipc_security_struct *isec, u16 sclass)
5910 {
5911 isec->sclass = sclass;
5912 isec->sid = current_sid();
5913 }
5914
ipc_has_perm(struct kern_ipc_perm * ipc_perms,u32 perms)5915 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
5916 u32 perms)
5917 {
5918 struct ipc_security_struct *isec;
5919 struct common_audit_data ad;
5920 u32 sid = current_sid();
5921
5922 isec = selinux_ipc(ipc_perms);
5923
5924 ad.type = LSM_AUDIT_DATA_IPC;
5925 ad.u.ipc_id = ipc_perms->key;
5926
5927 return avc_has_perm(&selinux_state,
5928 sid, isec->sid, isec->sclass, perms, &ad);
5929 }
5930
selinux_msg_msg_alloc_security(struct msg_msg * msg)5931 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
5932 {
5933 struct msg_security_struct *msec;
5934
5935 msec = selinux_msg_msg(msg);
5936 msec->sid = SECINITSID_UNLABELED;
5937
5938 return 0;
5939 }
5940
5941 /* message queue security operations */
selinux_msg_queue_alloc_security(struct kern_ipc_perm * msq)5942 static int selinux_msg_queue_alloc_security(struct kern_ipc_perm *msq)
5943 {
5944 struct ipc_security_struct *isec;
5945 struct common_audit_data ad;
5946 u32 sid = current_sid();
5947 int rc;
5948
5949 isec = selinux_ipc(msq);
5950 ipc_init_security(isec, SECCLASS_MSGQ);
5951
5952 ad.type = LSM_AUDIT_DATA_IPC;
5953 ad.u.ipc_id = msq->key;
5954
5955 rc = avc_has_perm(&selinux_state,
5956 sid, isec->sid, SECCLASS_MSGQ,
5957 MSGQ__CREATE, &ad);
5958 return rc;
5959 }
5960
selinux_msg_queue_associate(struct kern_ipc_perm * msq,int msqflg)5961 static int selinux_msg_queue_associate(struct kern_ipc_perm *msq, int msqflg)
5962 {
5963 struct ipc_security_struct *isec;
5964 struct common_audit_data ad;
5965 u32 sid = current_sid();
5966
5967 isec = selinux_ipc(msq);
5968
5969 ad.type = LSM_AUDIT_DATA_IPC;
5970 ad.u.ipc_id = msq->key;
5971
5972 return avc_has_perm(&selinux_state,
5973 sid, isec->sid, SECCLASS_MSGQ,
5974 MSGQ__ASSOCIATE, &ad);
5975 }
5976
selinux_msg_queue_msgctl(struct kern_ipc_perm * msq,int cmd)5977 static int selinux_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd)
5978 {
5979 int err;
5980 int perms;
5981
5982 switch (cmd) {
5983 case IPC_INFO:
5984 case MSG_INFO:
5985 /* No specific object, just general system-wide information. */
5986 return avc_has_perm(&selinux_state,
5987 current_sid(), SECINITSID_KERNEL,
5988 SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
5989 case IPC_STAT:
5990 case MSG_STAT:
5991 case MSG_STAT_ANY:
5992 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
5993 break;
5994 case IPC_SET:
5995 perms = MSGQ__SETATTR;
5996 break;
5997 case IPC_RMID:
5998 perms = MSGQ__DESTROY;
5999 break;
6000 default:
6001 return 0;
6002 }
6003
6004 err = ipc_has_perm(msq, perms);
6005 return err;
6006 }
6007
selinux_msg_queue_msgsnd(struct kern_ipc_perm * msq,struct msg_msg * msg,int msqflg)6008 static int selinux_msg_queue_msgsnd(struct kern_ipc_perm *msq, struct msg_msg *msg, int msqflg)
6009 {
6010 struct ipc_security_struct *isec;
6011 struct msg_security_struct *msec;
6012 struct common_audit_data ad;
6013 u32 sid = current_sid();
6014 int rc;
6015
6016 isec = selinux_ipc(msq);
6017 msec = selinux_msg_msg(msg);
6018
6019 /*
6020 * First time through, need to assign label to the message
6021 */
6022 if (msec->sid == SECINITSID_UNLABELED) {
6023 /*
6024 * Compute new sid based on current process and
6025 * message queue this message will be stored in
6026 */
6027 rc = security_transition_sid(&selinux_state, sid, isec->sid,
6028 SECCLASS_MSG, NULL, &msec->sid);
6029 if (rc)
6030 return rc;
6031 }
6032
6033 ad.type = LSM_AUDIT_DATA_IPC;
6034 ad.u.ipc_id = msq->key;
6035
6036 /* Can this process write to the queue? */
6037 rc = avc_has_perm(&selinux_state,
6038 sid, isec->sid, SECCLASS_MSGQ,
6039 MSGQ__WRITE, &ad);
6040 if (!rc)
6041 /* Can this process send the message */
6042 rc = avc_has_perm(&selinux_state,
6043 sid, msec->sid, SECCLASS_MSG,
6044 MSG__SEND, &ad);
6045 if (!rc)
6046 /* Can the message be put in the queue? */
6047 rc = avc_has_perm(&selinux_state,
6048 msec->sid, isec->sid, SECCLASS_MSGQ,
6049 MSGQ__ENQUEUE, &ad);
6050
6051 return rc;
6052 }
6053
selinux_msg_queue_msgrcv(struct kern_ipc_perm * msq,struct msg_msg * msg,struct task_struct * target,long type,int mode)6054 static int selinux_msg_queue_msgrcv(struct kern_ipc_perm *msq, struct msg_msg *msg,
6055 struct task_struct *target,
6056 long type, int mode)
6057 {
6058 struct ipc_security_struct *isec;
6059 struct msg_security_struct *msec;
6060 struct common_audit_data ad;
6061 u32 sid = task_sid(target);
6062 int rc;
6063
6064 isec = selinux_ipc(msq);
6065 msec = selinux_msg_msg(msg);
6066
6067 ad.type = LSM_AUDIT_DATA_IPC;
6068 ad.u.ipc_id = msq->key;
6069
6070 rc = avc_has_perm(&selinux_state,
6071 sid, isec->sid,
6072 SECCLASS_MSGQ, MSGQ__READ, &ad);
6073 if (!rc)
6074 rc = avc_has_perm(&selinux_state,
6075 sid, msec->sid,
6076 SECCLASS_MSG, MSG__RECEIVE, &ad);
6077 return rc;
6078 }
6079
6080 /* Shared Memory security operations */
selinux_shm_alloc_security(struct kern_ipc_perm * shp)6081 static int selinux_shm_alloc_security(struct kern_ipc_perm *shp)
6082 {
6083 struct ipc_security_struct *isec;
6084 struct common_audit_data ad;
6085 u32 sid = current_sid();
6086 int rc;
6087
6088 isec = selinux_ipc(shp);
6089 ipc_init_security(isec, SECCLASS_SHM);
6090
6091 ad.type = LSM_AUDIT_DATA_IPC;
6092 ad.u.ipc_id = shp->key;
6093
6094 rc = avc_has_perm(&selinux_state,
6095 sid, isec->sid, SECCLASS_SHM,
6096 SHM__CREATE, &ad);
6097 return rc;
6098 }
6099
selinux_shm_associate(struct kern_ipc_perm * shp,int shmflg)6100 static int selinux_shm_associate(struct kern_ipc_perm *shp, int shmflg)
6101 {
6102 struct ipc_security_struct *isec;
6103 struct common_audit_data ad;
6104 u32 sid = current_sid();
6105
6106 isec = selinux_ipc(shp);
6107
6108 ad.type = LSM_AUDIT_DATA_IPC;
6109 ad.u.ipc_id = shp->key;
6110
6111 return avc_has_perm(&selinux_state,
6112 sid, isec->sid, SECCLASS_SHM,
6113 SHM__ASSOCIATE, &ad);
6114 }
6115
6116 /* Note, at this point, shp is locked down */
selinux_shm_shmctl(struct kern_ipc_perm * shp,int cmd)6117 static int selinux_shm_shmctl(struct kern_ipc_perm *shp, int cmd)
6118 {
6119 int perms;
6120 int err;
6121
6122 switch (cmd) {
6123 case IPC_INFO:
6124 case SHM_INFO:
6125 /* No specific object, just general system-wide information. */
6126 return avc_has_perm(&selinux_state,
6127 current_sid(), SECINITSID_KERNEL,
6128 SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6129 case IPC_STAT:
6130 case SHM_STAT:
6131 case SHM_STAT_ANY:
6132 perms = SHM__GETATTR | SHM__ASSOCIATE;
6133 break;
6134 case IPC_SET:
6135 perms = SHM__SETATTR;
6136 break;
6137 case SHM_LOCK:
6138 case SHM_UNLOCK:
6139 perms = SHM__LOCK;
6140 break;
6141 case IPC_RMID:
6142 perms = SHM__DESTROY;
6143 break;
6144 default:
6145 return 0;
6146 }
6147
6148 err = ipc_has_perm(shp, perms);
6149 return err;
6150 }
6151
selinux_shm_shmat(struct kern_ipc_perm * shp,char __user * shmaddr,int shmflg)6152 static int selinux_shm_shmat(struct kern_ipc_perm *shp,
6153 char __user *shmaddr, int shmflg)
6154 {
6155 u32 perms;
6156
6157 if (shmflg & SHM_RDONLY)
6158 perms = SHM__READ;
6159 else
6160 perms = SHM__READ | SHM__WRITE;
6161
6162 return ipc_has_perm(shp, perms);
6163 }
6164
6165 /* Semaphore security operations */
selinux_sem_alloc_security(struct kern_ipc_perm * sma)6166 static int selinux_sem_alloc_security(struct kern_ipc_perm *sma)
6167 {
6168 struct ipc_security_struct *isec;
6169 struct common_audit_data ad;
6170 u32 sid = current_sid();
6171 int rc;
6172
6173 isec = selinux_ipc(sma);
6174 ipc_init_security(isec, SECCLASS_SEM);
6175
6176 ad.type = LSM_AUDIT_DATA_IPC;
6177 ad.u.ipc_id = sma->key;
6178
6179 rc = avc_has_perm(&selinux_state,
6180 sid, isec->sid, SECCLASS_SEM,
6181 SEM__CREATE, &ad);
6182 return rc;
6183 }
6184
selinux_sem_associate(struct kern_ipc_perm * sma,int semflg)6185 static int selinux_sem_associate(struct kern_ipc_perm *sma, int semflg)
6186 {
6187 struct ipc_security_struct *isec;
6188 struct common_audit_data ad;
6189 u32 sid = current_sid();
6190
6191 isec = selinux_ipc(sma);
6192
6193 ad.type = LSM_AUDIT_DATA_IPC;
6194 ad.u.ipc_id = sma->key;
6195
6196 return avc_has_perm(&selinux_state,
6197 sid, isec->sid, SECCLASS_SEM,
6198 SEM__ASSOCIATE, &ad);
6199 }
6200
6201 /* Note, at this point, sma is locked down */
selinux_sem_semctl(struct kern_ipc_perm * sma,int cmd)6202 static int selinux_sem_semctl(struct kern_ipc_perm *sma, int cmd)
6203 {
6204 int err;
6205 u32 perms;
6206
6207 switch (cmd) {
6208 case IPC_INFO:
6209 case SEM_INFO:
6210 /* No specific object, just general system-wide information. */
6211 return avc_has_perm(&selinux_state,
6212 current_sid(), SECINITSID_KERNEL,
6213 SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6214 case GETPID:
6215 case GETNCNT:
6216 case GETZCNT:
6217 perms = SEM__GETATTR;
6218 break;
6219 case GETVAL:
6220 case GETALL:
6221 perms = SEM__READ;
6222 break;
6223 case SETVAL:
6224 case SETALL:
6225 perms = SEM__WRITE;
6226 break;
6227 case IPC_RMID:
6228 perms = SEM__DESTROY;
6229 break;
6230 case IPC_SET:
6231 perms = SEM__SETATTR;
6232 break;
6233 case IPC_STAT:
6234 case SEM_STAT:
6235 case SEM_STAT_ANY:
6236 perms = SEM__GETATTR | SEM__ASSOCIATE;
6237 break;
6238 default:
6239 return 0;
6240 }
6241
6242 err = ipc_has_perm(sma, perms);
6243 return err;
6244 }
6245
selinux_sem_semop(struct kern_ipc_perm * sma,struct sembuf * sops,unsigned nsops,int alter)6246 static int selinux_sem_semop(struct kern_ipc_perm *sma,
6247 struct sembuf *sops, unsigned nsops, int alter)
6248 {
6249 u32 perms;
6250
6251 if (alter)
6252 perms = SEM__READ | SEM__WRITE;
6253 else
6254 perms = SEM__READ;
6255
6256 return ipc_has_perm(sma, perms);
6257 }
6258
selinux_ipc_permission(struct kern_ipc_perm * ipcp,short flag)6259 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
6260 {
6261 u32 av = 0;
6262
6263 av = 0;
6264 if (flag & S_IRUGO)
6265 av |= IPC__UNIX_READ;
6266 if (flag & S_IWUGO)
6267 av |= IPC__UNIX_WRITE;
6268
6269 if (av == 0)
6270 return 0;
6271
6272 return ipc_has_perm(ipcp, av);
6273 }
6274
selinux_ipc_getsecid(struct kern_ipc_perm * ipcp,u32 * secid)6275 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
6276 {
6277 struct ipc_security_struct *isec = selinux_ipc(ipcp);
6278 *secid = isec->sid;
6279 }
6280
selinux_d_instantiate(struct dentry * dentry,struct inode * inode)6281 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
6282 {
6283 if (inode)
6284 inode_doinit_with_dentry(inode, dentry);
6285 }
6286
selinux_getprocattr(struct task_struct * p,char * name,char ** value)6287 static int selinux_getprocattr(struct task_struct *p,
6288 char *name, char **value)
6289 {
6290 const struct task_security_struct *__tsec;
6291 u32 sid;
6292 int error;
6293 unsigned len;
6294
6295 rcu_read_lock();
6296 __tsec = selinux_cred(__task_cred(p));
6297
6298 if (current != p) {
6299 error = avc_has_perm(&selinux_state,
6300 current_sid(), __tsec->sid,
6301 SECCLASS_PROCESS, PROCESS__GETATTR, NULL);
6302 if (error)
6303 goto bad;
6304 }
6305
6306 if (!strcmp(name, "current"))
6307 sid = __tsec->sid;
6308 else if (!strcmp(name, "prev"))
6309 sid = __tsec->osid;
6310 else if (!strcmp(name, "exec"))
6311 sid = __tsec->exec_sid;
6312 else if (!strcmp(name, "fscreate"))
6313 sid = __tsec->create_sid;
6314 else if (!strcmp(name, "keycreate"))
6315 sid = __tsec->keycreate_sid;
6316 else if (!strcmp(name, "sockcreate"))
6317 sid = __tsec->sockcreate_sid;
6318 else {
6319 error = -EINVAL;
6320 goto bad;
6321 }
6322 rcu_read_unlock();
6323
6324 if (!sid)
6325 return 0;
6326
6327 error = security_sid_to_context(&selinux_state, sid, value, &len);
6328 if (error)
6329 return error;
6330 return len;
6331
6332 bad:
6333 rcu_read_unlock();
6334 return error;
6335 }
6336
selinux_setprocattr(const char * name,void * value,size_t size)6337 static int selinux_setprocattr(const char *name, void *value, size_t size)
6338 {
6339 struct task_security_struct *tsec;
6340 struct cred *new;
6341 u32 mysid = current_sid(), sid = 0, ptsid;
6342 int error;
6343 char *str = value;
6344
6345 /*
6346 * Basic control over ability to set these attributes at all.
6347 */
6348 if (!strcmp(name, "exec"))
6349 error = avc_has_perm(&selinux_state,
6350 mysid, mysid, SECCLASS_PROCESS,
6351 PROCESS__SETEXEC, NULL);
6352 else if (!strcmp(name, "fscreate"))
6353 error = avc_has_perm(&selinux_state,
6354 mysid, mysid, SECCLASS_PROCESS,
6355 PROCESS__SETFSCREATE, NULL);
6356 else if (!strcmp(name, "keycreate"))
6357 error = avc_has_perm(&selinux_state,
6358 mysid, mysid, SECCLASS_PROCESS,
6359 PROCESS__SETKEYCREATE, NULL);
6360 else if (!strcmp(name, "sockcreate"))
6361 error = avc_has_perm(&selinux_state,
6362 mysid, mysid, SECCLASS_PROCESS,
6363 PROCESS__SETSOCKCREATE, NULL);
6364 else if (!strcmp(name, "current"))
6365 error = avc_has_perm(&selinux_state,
6366 mysid, mysid, SECCLASS_PROCESS,
6367 PROCESS__SETCURRENT, NULL);
6368 else
6369 error = -EINVAL;
6370 if (error)
6371 return error;
6372
6373 /* Obtain a SID for the context, if one was specified. */
6374 if (size && str[0] && str[0] != '\n') {
6375 if (str[size-1] == '\n') {
6376 str[size-1] = 0;
6377 size--;
6378 }
6379 error = security_context_to_sid(&selinux_state, value, size,
6380 &sid, GFP_KERNEL);
6381 if (error == -EINVAL && !strcmp(name, "fscreate")) {
6382 if (!has_cap_mac_admin(true)) {
6383 struct audit_buffer *ab;
6384 size_t audit_size;
6385
6386 /* We strip a nul only if it is at the end, otherwise the
6387 * context contains a nul and we should audit that */
6388 if (str[size - 1] == '\0')
6389 audit_size = size - 1;
6390 else
6391 audit_size = size;
6392 ab = audit_log_start(audit_context(),
6393 GFP_ATOMIC,
6394 AUDIT_SELINUX_ERR);
6395 audit_log_format(ab, "op=fscreate invalid_context=");
6396 audit_log_n_untrustedstring(ab, value, audit_size);
6397 audit_log_end(ab);
6398
6399 return error;
6400 }
6401 error = security_context_to_sid_force(
6402 &selinux_state,
6403 value, size, &sid);
6404 }
6405 if (error)
6406 return error;
6407 }
6408
6409 new = prepare_creds();
6410 if (!new)
6411 return -ENOMEM;
6412
6413 /* Permission checking based on the specified context is
6414 performed during the actual operation (execve,
6415 open/mkdir/...), when we know the full context of the
6416 operation. See selinux_bprm_creds_for_exec for the execve
6417 checks and may_create for the file creation checks. The
6418 operation will then fail if the context is not permitted. */
6419 tsec = selinux_cred(new);
6420 if (!strcmp(name, "exec")) {
6421 tsec->exec_sid = sid;
6422 } else if (!strcmp(name, "fscreate")) {
6423 tsec->create_sid = sid;
6424 } else if (!strcmp(name, "keycreate")) {
6425 if (sid) {
6426 error = avc_has_perm(&selinux_state, mysid, sid,
6427 SECCLASS_KEY, KEY__CREATE, NULL);
6428 if (error)
6429 goto abort_change;
6430 }
6431 tsec->keycreate_sid = sid;
6432 } else if (!strcmp(name, "sockcreate")) {
6433 tsec->sockcreate_sid = sid;
6434 } else if (!strcmp(name, "current")) {
6435 error = -EINVAL;
6436 if (sid == 0)
6437 goto abort_change;
6438
6439 /* Only allow single threaded processes to change context */
6440 error = -EPERM;
6441 if (!current_is_single_threaded()) {
6442 error = security_bounded_transition(&selinux_state,
6443 tsec->sid, sid);
6444 if (error)
6445 goto abort_change;
6446 }
6447
6448 /* Check permissions for the transition. */
6449 error = avc_has_perm(&selinux_state,
6450 tsec->sid, sid, SECCLASS_PROCESS,
6451 PROCESS__DYNTRANSITION, NULL);
6452 if (error)
6453 goto abort_change;
6454
6455 /* Check for ptracing, and update the task SID if ok.
6456 Otherwise, leave SID unchanged and fail. */
6457 ptsid = ptrace_parent_sid();
6458 if (ptsid != 0) {
6459 error = avc_has_perm(&selinux_state,
6460 ptsid, sid, SECCLASS_PROCESS,
6461 PROCESS__PTRACE, NULL);
6462 if (error)
6463 goto abort_change;
6464 }
6465
6466 tsec->sid = sid;
6467 } else {
6468 error = -EINVAL;
6469 goto abort_change;
6470 }
6471
6472 commit_creds(new);
6473 return size;
6474
6475 abort_change:
6476 abort_creds(new);
6477 return error;
6478 }
6479
selinux_ismaclabel(const char * name)6480 static int selinux_ismaclabel(const char *name)
6481 {
6482 return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
6483 }
6484
selinux_secid_to_secctx(u32 secid,char ** secdata,u32 * seclen)6485 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
6486 {
6487 return security_sid_to_context(&selinux_state, secid,
6488 secdata, seclen);
6489 }
6490
selinux_secctx_to_secid(const char * secdata,u32 seclen,u32 * secid)6491 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
6492 {
6493 return security_context_to_sid(&selinux_state, secdata, seclen,
6494 secid, GFP_KERNEL);
6495 }
6496
selinux_release_secctx(char * secdata,u32 seclen)6497 static void selinux_release_secctx(char *secdata, u32 seclen)
6498 {
6499 kfree(secdata);
6500 }
6501
selinux_inode_invalidate_secctx(struct inode * inode)6502 static void selinux_inode_invalidate_secctx(struct inode *inode)
6503 {
6504 struct inode_security_struct *isec = selinux_inode(inode);
6505
6506 spin_lock(&isec->lock);
6507 isec->initialized = LABEL_INVALID;
6508 spin_unlock(&isec->lock);
6509 }
6510
6511 /*
6512 * called with inode->i_mutex locked
6513 */
selinux_inode_notifysecctx(struct inode * inode,void * ctx,u32 ctxlen)6514 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
6515 {
6516 int rc = selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX,
6517 ctx, ctxlen, 0);
6518 /* Do not return error when suppressing label (SBLABEL_MNT not set). */
6519 return rc == -EOPNOTSUPP ? 0 : rc;
6520 }
6521
6522 /*
6523 * called with inode->i_mutex locked
6524 */
selinux_inode_setsecctx(struct dentry * dentry,void * ctx,u32 ctxlen)6525 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
6526 {
6527 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
6528 }
6529
selinux_inode_getsecctx(struct inode * inode,void ** ctx,u32 * ctxlen)6530 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
6531 {
6532 int len = 0;
6533 len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
6534 ctx, true);
6535 if (len < 0)
6536 return len;
6537 *ctxlen = len;
6538 return 0;
6539 }
6540 #ifdef CONFIG_KEYS
6541
selinux_key_alloc(struct key * k,const struct cred * cred,unsigned long flags)6542 static int selinux_key_alloc(struct key *k, const struct cred *cred,
6543 unsigned long flags)
6544 {
6545 const struct task_security_struct *tsec;
6546 struct key_security_struct *ksec;
6547
6548 ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
6549 if (!ksec)
6550 return -ENOMEM;
6551
6552 tsec = selinux_cred(cred);
6553 if (tsec->keycreate_sid)
6554 ksec->sid = tsec->keycreate_sid;
6555 else
6556 ksec->sid = tsec->sid;
6557
6558 k->security = ksec;
6559 return 0;
6560 }
6561
selinux_key_free(struct key * k)6562 static void selinux_key_free(struct key *k)
6563 {
6564 struct key_security_struct *ksec = k->security;
6565
6566 k->security = NULL;
6567 kfree(ksec);
6568 }
6569
selinux_key_permission(key_ref_t key_ref,const struct cred * cred,enum key_need_perm need_perm)6570 static int selinux_key_permission(key_ref_t key_ref,
6571 const struct cred *cred,
6572 enum key_need_perm need_perm)
6573 {
6574 struct key *key;
6575 struct key_security_struct *ksec;
6576 u32 perm, sid;
6577
6578 switch (need_perm) {
6579 case KEY_NEED_VIEW:
6580 perm = KEY__VIEW;
6581 break;
6582 case KEY_NEED_READ:
6583 perm = KEY__READ;
6584 break;
6585 case KEY_NEED_WRITE:
6586 perm = KEY__WRITE;
6587 break;
6588 case KEY_NEED_SEARCH:
6589 perm = KEY__SEARCH;
6590 break;
6591 case KEY_NEED_LINK:
6592 perm = KEY__LINK;
6593 break;
6594 case KEY_NEED_SETATTR:
6595 perm = KEY__SETATTR;
6596 break;
6597 case KEY_NEED_UNLINK:
6598 case KEY_SYSADMIN_OVERRIDE:
6599 case KEY_AUTHTOKEN_OVERRIDE:
6600 case KEY_DEFER_PERM_CHECK:
6601 return 0;
6602 default:
6603 WARN_ON(1);
6604 return -EPERM;
6605
6606 }
6607
6608 sid = cred_sid(cred);
6609 key = key_ref_to_ptr(key_ref);
6610 ksec = key->security;
6611
6612 return avc_has_perm(&selinux_state,
6613 sid, ksec->sid, SECCLASS_KEY, perm, NULL);
6614 }
6615
selinux_key_getsecurity(struct key * key,char ** _buffer)6616 static int selinux_key_getsecurity(struct key *key, char **_buffer)
6617 {
6618 struct key_security_struct *ksec = key->security;
6619 char *context = NULL;
6620 unsigned len;
6621 int rc;
6622
6623 rc = security_sid_to_context(&selinux_state, ksec->sid,
6624 &context, &len);
6625 if (!rc)
6626 rc = len;
6627 *_buffer = context;
6628 return rc;
6629 }
6630
6631 #ifdef CONFIG_KEY_NOTIFICATIONS
selinux_watch_key(struct key * key)6632 static int selinux_watch_key(struct key *key)
6633 {
6634 struct key_security_struct *ksec = key->security;
6635 u32 sid = current_sid();
6636
6637 return avc_has_perm(&selinux_state,
6638 sid, ksec->sid, SECCLASS_KEY, KEY__VIEW, NULL);
6639 }
6640 #endif
6641 #endif
6642
6643 #ifdef CONFIG_SECURITY_INFINIBAND
selinux_ib_pkey_access(void * ib_sec,u64 subnet_prefix,u16 pkey_val)6644 static int selinux_ib_pkey_access(void *ib_sec, u64 subnet_prefix, u16 pkey_val)
6645 {
6646 struct common_audit_data ad;
6647 int err;
6648 u32 sid = 0;
6649 struct ib_security_struct *sec = ib_sec;
6650 struct lsm_ibpkey_audit ibpkey;
6651
6652 err = sel_ib_pkey_sid(subnet_prefix, pkey_val, &sid);
6653 if (err)
6654 return err;
6655
6656 ad.type = LSM_AUDIT_DATA_IBPKEY;
6657 ibpkey.subnet_prefix = subnet_prefix;
6658 ibpkey.pkey = pkey_val;
6659 ad.u.ibpkey = &ibpkey;
6660 return avc_has_perm(&selinux_state,
6661 sec->sid, sid,
6662 SECCLASS_INFINIBAND_PKEY,
6663 INFINIBAND_PKEY__ACCESS, &ad);
6664 }
6665
selinux_ib_endport_manage_subnet(void * ib_sec,const char * dev_name,u8 port_num)6666 static int selinux_ib_endport_manage_subnet(void *ib_sec, const char *dev_name,
6667 u8 port_num)
6668 {
6669 struct common_audit_data ad;
6670 int err;
6671 u32 sid = 0;
6672 struct ib_security_struct *sec = ib_sec;
6673 struct lsm_ibendport_audit ibendport;
6674
6675 err = security_ib_endport_sid(&selinux_state, dev_name, port_num,
6676 &sid);
6677
6678 if (err)
6679 return err;
6680
6681 ad.type = LSM_AUDIT_DATA_IBENDPORT;
6682 strncpy(ibendport.dev_name, dev_name, sizeof(ibendport.dev_name));
6683 ibendport.port = port_num;
6684 ad.u.ibendport = &ibendport;
6685 return avc_has_perm(&selinux_state,
6686 sec->sid, sid,
6687 SECCLASS_INFINIBAND_ENDPORT,
6688 INFINIBAND_ENDPORT__MANAGE_SUBNET, &ad);
6689 }
6690
selinux_ib_alloc_security(void ** ib_sec)6691 static int selinux_ib_alloc_security(void **ib_sec)
6692 {
6693 struct ib_security_struct *sec;
6694
6695 sec = kzalloc(sizeof(*sec), GFP_KERNEL);
6696 if (!sec)
6697 return -ENOMEM;
6698 sec->sid = current_sid();
6699
6700 *ib_sec = sec;
6701 return 0;
6702 }
6703
selinux_ib_free_security(void * ib_sec)6704 static void selinux_ib_free_security(void *ib_sec)
6705 {
6706 kfree(ib_sec);
6707 }
6708 #endif
6709
6710 #ifdef CONFIG_BPF_SYSCALL
selinux_bpf(int cmd,union bpf_attr * attr,unsigned int size)6711 static int selinux_bpf(int cmd, union bpf_attr *attr,
6712 unsigned int size)
6713 {
6714 u32 sid = current_sid();
6715 int ret;
6716
6717 switch (cmd) {
6718 case BPF_MAP_CREATE:
6719 ret = avc_has_perm(&selinux_state,
6720 sid, sid, SECCLASS_BPF, BPF__MAP_CREATE,
6721 NULL);
6722 break;
6723 case BPF_PROG_LOAD:
6724 ret = avc_has_perm(&selinux_state,
6725 sid, sid, SECCLASS_BPF, BPF__PROG_LOAD,
6726 NULL);
6727 break;
6728 default:
6729 ret = 0;
6730 break;
6731 }
6732
6733 return ret;
6734 }
6735
bpf_map_fmode_to_av(fmode_t fmode)6736 static u32 bpf_map_fmode_to_av(fmode_t fmode)
6737 {
6738 u32 av = 0;
6739
6740 if (fmode & FMODE_READ)
6741 av |= BPF__MAP_READ;
6742 if (fmode & FMODE_WRITE)
6743 av |= BPF__MAP_WRITE;
6744 return av;
6745 }
6746
6747 /* This function will check the file pass through unix socket or binder to see
6748 * if it is a bpf related object. And apply correspinding checks on the bpf
6749 * object based on the type. The bpf maps and programs, not like other files and
6750 * socket, are using a shared anonymous inode inside the kernel as their inode.
6751 * So checking that inode cannot identify if the process have privilege to
6752 * access the bpf object and that's why we have to add this additional check in
6753 * selinux_file_receive and selinux_binder_transfer_files.
6754 */
bpf_fd_pass(struct file * file,u32 sid)6755 static int bpf_fd_pass(struct file *file, u32 sid)
6756 {
6757 struct bpf_security_struct *bpfsec;
6758 struct bpf_prog *prog;
6759 struct bpf_map *map;
6760 int ret;
6761
6762 if (file->f_op == &bpf_map_fops) {
6763 map = file->private_data;
6764 bpfsec = map->security;
6765 ret = avc_has_perm(&selinux_state,
6766 sid, bpfsec->sid, SECCLASS_BPF,
6767 bpf_map_fmode_to_av(file->f_mode), NULL);
6768 if (ret)
6769 return ret;
6770 } else if (file->f_op == &bpf_prog_fops) {
6771 prog = file->private_data;
6772 bpfsec = prog->aux->security;
6773 ret = avc_has_perm(&selinux_state,
6774 sid, bpfsec->sid, SECCLASS_BPF,
6775 BPF__PROG_RUN, NULL);
6776 if (ret)
6777 return ret;
6778 }
6779 return 0;
6780 }
6781
selinux_bpf_map(struct bpf_map * map,fmode_t fmode)6782 static int selinux_bpf_map(struct bpf_map *map, fmode_t fmode)
6783 {
6784 u32 sid = current_sid();
6785 struct bpf_security_struct *bpfsec;
6786
6787 bpfsec = map->security;
6788 return avc_has_perm(&selinux_state,
6789 sid, bpfsec->sid, SECCLASS_BPF,
6790 bpf_map_fmode_to_av(fmode), NULL);
6791 }
6792
selinux_bpf_prog(struct bpf_prog * prog)6793 static int selinux_bpf_prog(struct bpf_prog *prog)
6794 {
6795 u32 sid = current_sid();
6796 struct bpf_security_struct *bpfsec;
6797
6798 bpfsec = prog->aux->security;
6799 return avc_has_perm(&selinux_state,
6800 sid, bpfsec->sid, SECCLASS_BPF,
6801 BPF__PROG_RUN, NULL);
6802 }
6803
selinux_bpf_map_alloc(struct bpf_map * map)6804 static int selinux_bpf_map_alloc(struct bpf_map *map)
6805 {
6806 struct bpf_security_struct *bpfsec;
6807
6808 bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
6809 if (!bpfsec)
6810 return -ENOMEM;
6811
6812 bpfsec->sid = current_sid();
6813 map->security = bpfsec;
6814
6815 return 0;
6816 }
6817
selinux_bpf_map_free(struct bpf_map * map)6818 static void selinux_bpf_map_free(struct bpf_map *map)
6819 {
6820 struct bpf_security_struct *bpfsec = map->security;
6821
6822 map->security = NULL;
6823 kfree(bpfsec);
6824 }
6825
selinux_bpf_prog_alloc(struct bpf_prog_aux * aux)6826 static int selinux_bpf_prog_alloc(struct bpf_prog_aux *aux)
6827 {
6828 struct bpf_security_struct *bpfsec;
6829
6830 bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
6831 if (!bpfsec)
6832 return -ENOMEM;
6833
6834 bpfsec->sid = current_sid();
6835 aux->security = bpfsec;
6836
6837 return 0;
6838 }
6839
selinux_bpf_prog_free(struct bpf_prog_aux * aux)6840 static void selinux_bpf_prog_free(struct bpf_prog_aux *aux)
6841 {
6842 struct bpf_security_struct *bpfsec = aux->security;
6843
6844 aux->security = NULL;
6845 kfree(bpfsec);
6846 }
6847 #endif
6848
selinux_lockdown(enum lockdown_reason what)6849 static int selinux_lockdown(enum lockdown_reason what)
6850 {
6851 struct common_audit_data ad;
6852 u32 sid = current_sid();
6853 int invalid_reason = (what <= LOCKDOWN_NONE) ||
6854 (what == LOCKDOWN_INTEGRITY_MAX) ||
6855 (what >= LOCKDOWN_CONFIDENTIALITY_MAX);
6856
6857 if (WARN(invalid_reason, "Invalid lockdown reason")) {
6858 audit_log(audit_context(),
6859 GFP_ATOMIC, AUDIT_SELINUX_ERR,
6860 "lockdown_reason=invalid");
6861 return -EINVAL;
6862 }
6863
6864 ad.type = LSM_AUDIT_DATA_LOCKDOWN;
6865 ad.u.reason = what;
6866
6867 if (what <= LOCKDOWN_INTEGRITY_MAX)
6868 return avc_has_perm(&selinux_state,
6869 sid, sid, SECCLASS_LOCKDOWN,
6870 LOCKDOWN__INTEGRITY, &ad);
6871 else
6872 return avc_has_perm(&selinux_state,
6873 sid, sid, SECCLASS_LOCKDOWN,
6874 LOCKDOWN__CONFIDENTIALITY, &ad);
6875 }
6876
6877 struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = {
6878 .lbs_cred = sizeof(struct task_security_struct),
6879 .lbs_file = sizeof(struct file_security_struct),
6880 .lbs_inode = sizeof(struct inode_security_struct),
6881 .lbs_ipc = sizeof(struct ipc_security_struct),
6882 .lbs_msg_msg = sizeof(struct msg_security_struct),
6883 };
6884
6885 #ifdef CONFIG_PERF_EVENTS
selinux_perf_event_open(struct perf_event_attr * attr,int type)6886 static int selinux_perf_event_open(struct perf_event_attr *attr, int type)
6887 {
6888 u32 requested, sid = current_sid();
6889
6890 if (type == PERF_SECURITY_OPEN)
6891 requested = PERF_EVENT__OPEN;
6892 else if (type == PERF_SECURITY_CPU)
6893 requested = PERF_EVENT__CPU;
6894 else if (type == PERF_SECURITY_KERNEL)
6895 requested = PERF_EVENT__KERNEL;
6896 else if (type == PERF_SECURITY_TRACEPOINT)
6897 requested = PERF_EVENT__TRACEPOINT;
6898 else
6899 return -EINVAL;
6900
6901 return avc_has_perm(&selinux_state, sid, sid, SECCLASS_PERF_EVENT,
6902 requested, NULL);
6903 }
6904
selinux_perf_event_alloc(struct perf_event * event)6905 static int selinux_perf_event_alloc(struct perf_event *event)
6906 {
6907 struct perf_event_security_struct *perfsec;
6908
6909 perfsec = kzalloc(sizeof(*perfsec), GFP_KERNEL);
6910 if (!perfsec)
6911 return -ENOMEM;
6912
6913 perfsec->sid = current_sid();
6914 event->security = perfsec;
6915
6916 return 0;
6917 }
6918
selinux_perf_event_free(struct perf_event * event)6919 static void selinux_perf_event_free(struct perf_event *event)
6920 {
6921 struct perf_event_security_struct *perfsec = event->security;
6922
6923 event->security = NULL;
6924 kfree(perfsec);
6925 }
6926
selinux_perf_event_read(struct perf_event * event)6927 static int selinux_perf_event_read(struct perf_event *event)
6928 {
6929 struct perf_event_security_struct *perfsec = event->security;
6930 u32 sid = current_sid();
6931
6932 return avc_has_perm(&selinux_state, sid, perfsec->sid,
6933 SECCLASS_PERF_EVENT, PERF_EVENT__READ, NULL);
6934 }
6935
selinux_perf_event_write(struct perf_event * event)6936 static int selinux_perf_event_write(struct perf_event *event)
6937 {
6938 struct perf_event_security_struct *perfsec = event->security;
6939 u32 sid = current_sid();
6940
6941 return avc_has_perm(&selinux_state, sid, perfsec->sid,
6942 SECCLASS_PERF_EVENT, PERF_EVENT__WRITE, NULL);
6943 }
6944 #endif
6945
6946 /*
6947 * IMPORTANT NOTE: When adding new hooks, please be careful to keep this order:
6948 * 1. any hooks that don't belong to (2.) or (3.) below,
6949 * 2. hooks that both access structures allocated by other hooks, and allocate
6950 * structures that can be later accessed by other hooks (mostly "cloning"
6951 * hooks),
6952 * 3. hooks that only allocate structures that can be later accessed by other
6953 * hooks ("allocating" hooks).
6954 *
6955 * Please follow block comment delimiters in the list to keep this order.
6956 *
6957 * This ordering is needed for SELinux runtime disable to work at least somewhat
6958 * safely. Breaking the ordering rules above might lead to NULL pointer derefs
6959 * when disabling SELinux at runtime.
6960 */
6961 static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
6962 LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr),
6963 LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction),
6964 LSM_HOOK_INIT(binder_transfer_binder, selinux_binder_transfer_binder),
6965 LSM_HOOK_INIT(binder_transfer_file, selinux_binder_transfer_file),
6966
6967 LSM_HOOK_INIT(ptrace_access_check, selinux_ptrace_access_check),
6968 LSM_HOOK_INIT(ptrace_traceme, selinux_ptrace_traceme),
6969 LSM_HOOK_INIT(capget, selinux_capget),
6970 LSM_HOOK_INIT(capset, selinux_capset),
6971 LSM_HOOK_INIT(capable, selinux_capable),
6972 LSM_HOOK_INIT(quotactl, selinux_quotactl),
6973 LSM_HOOK_INIT(quota_on, selinux_quota_on),
6974 LSM_HOOK_INIT(syslog, selinux_syslog),
6975 LSM_HOOK_INIT(vm_enough_memory, selinux_vm_enough_memory),
6976
6977 LSM_HOOK_INIT(netlink_send, selinux_netlink_send),
6978
6979 LSM_HOOK_INIT(bprm_creds_for_exec, selinux_bprm_creds_for_exec),
6980 LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds),
6981 LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds),
6982
6983 LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security),
6984 LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts),
6985 LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
6986 LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
6987 LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
6988 LSM_HOOK_INIT(sb_statfs, selinux_sb_statfs),
6989 LSM_HOOK_INIT(sb_mount, selinux_mount),
6990 LSM_HOOK_INIT(sb_umount, selinux_umount),
6991 LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts),
6992 LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
6993
6994 LSM_HOOK_INIT(move_mount, selinux_move_mount),
6995
6996 LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security),
6997 LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),
6998
6999 LSM_HOOK_INIT(inode_free_security, selinux_inode_free_security),
7000 LSM_HOOK_INIT(inode_init_security, selinux_inode_init_security),
7001 LSM_HOOK_INIT(inode_create, selinux_inode_create),
7002 LSM_HOOK_INIT(inode_link, selinux_inode_link),
7003 LSM_HOOK_INIT(inode_unlink, selinux_inode_unlink),
7004 LSM_HOOK_INIT(inode_symlink, selinux_inode_symlink),
7005 LSM_HOOK_INIT(inode_mkdir, selinux_inode_mkdir),
7006 LSM_HOOK_INIT(inode_rmdir, selinux_inode_rmdir),
7007 LSM_HOOK_INIT(inode_mknod, selinux_inode_mknod),
7008 LSM_HOOK_INIT(inode_rename, selinux_inode_rename),
7009 LSM_HOOK_INIT(inode_readlink, selinux_inode_readlink),
7010 LSM_HOOK_INIT(inode_follow_link, selinux_inode_follow_link),
7011 LSM_HOOK_INIT(inode_permission, selinux_inode_permission),
7012 LSM_HOOK_INIT(inode_setattr, selinux_inode_setattr),
7013 LSM_HOOK_INIT(inode_getattr, selinux_inode_getattr),
7014 LSM_HOOK_INIT(inode_setxattr, selinux_inode_setxattr),
7015 LSM_HOOK_INIT(inode_post_setxattr, selinux_inode_post_setxattr),
7016 LSM_HOOK_INIT(inode_getxattr, selinux_inode_getxattr),
7017 LSM_HOOK_INIT(inode_listxattr, selinux_inode_listxattr),
7018 LSM_HOOK_INIT(inode_removexattr, selinux_inode_removexattr),
7019 LSM_HOOK_INIT(inode_getsecurity, selinux_inode_getsecurity),
7020 LSM_HOOK_INIT(inode_setsecurity, selinux_inode_setsecurity),
7021 LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity),
7022 LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid),
7023 LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
7024 LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
7025 LSM_HOOK_INIT(path_notify, selinux_path_notify),
7026
7027 LSM_HOOK_INIT(kernfs_init_security, selinux_kernfs_init_security),
7028
7029 LSM_HOOK_INIT(file_permission, selinux_file_permission),
7030 LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),
7031 LSM_HOOK_INIT(file_ioctl, selinux_file_ioctl),
7032 LSM_HOOK_INIT(mmap_file, selinux_mmap_file),
7033 LSM_HOOK_INIT(mmap_addr, selinux_mmap_addr),
7034 LSM_HOOK_INIT(file_mprotect, selinux_file_mprotect),
7035 LSM_HOOK_INIT(file_lock, selinux_file_lock),
7036 LSM_HOOK_INIT(file_fcntl, selinux_file_fcntl),
7037 LSM_HOOK_INIT(file_set_fowner, selinux_file_set_fowner),
7038 LSM_HOOK_INIT(file_send_sigiotask, selinux_file_send_sigiotask),
7039 LSM_HOOK_INIT(file_receive, selinux_file_receive),
7040
7041 LSM_HOOK_INIT(file_open, selinux_file_open),
7042
7043 LSM_HOOK_INIT(task_alloc, selinux_task_alloc),
7044 LSM_HOOK_INIT(cred_prepare, selinux_cred_prepare),
7045 LSM_HOOK_INIT(cred_transfer, selinux_cred_transfer),
7046 LSM_HOOK_INIT(cred_getsecid, selinux_cred_getsecid),
7047 LSM_HOOK_INIT(kernel_act_as, selinux_kernel_act_as),
7048 LSM_HOOK_INIT(kernel_create_files_as, selinux_kernel_create_files_as),
7049 LSM_HOOK_INIT(kernel_module_request, selinux_kernel_module_request),
7050 LSM_HOOK_INIT(kernel_load_data, selinux_kernel_load_data),
7051 LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file),
7052 LSM_HOOK_INIT(task_setpgid, selinux_task_setpgid),
7053 LSM_HOOK_INIT(task_getpgid, selinux_task_getpgid),
7054 LSM_HOOK_INIT(task_getsid, selinux_task_getsid),
7055 LSM_HOOK_INIT(task_getsecid, selinux_task_getsecid),
7056 LSM_HOOK_INIT(task_setnice, selinux_task_setnice),
7057 LSM_HOOK_INIT(task_setioprio, selinux_task_setioprio),
7058 LSM_HOOK_INIT(task_getioprio, selinux_task_getioprio),
7059 LSM_HOOK_INIT(task_prlimit, selinux_task_prlimit),
7060 LSM_HOOK_INIT(task_setrlimit, selinux_task_setrlimit),
7061 LSM_HOOK_INIT(task_setscheduler, selinux_task_setscheduler),
7062 LSM_HOOK_INIT(task_getscheduler, selinux_task_getscheduler),
7063 LSM_HOOK_INIT(task_movememory, selinux_task_movememory),
7064 LSM_HOOK_INIT(task_kill, selinux_task_kill),
7065 LSM_HOOK_INIT(task_to_inode, selinux_task_to_inode),
7066
7067 LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission),
7068 LSM_HOOK_INIT(ipc_getsecid, selinux_ipc_getsecid),
7069
7070 LSM_HOOK_INIT(msg_queue_associate, selinux_msg_queue_associate),
7071 LSM_HOOK_INIT(msg_queue_msgctl, selinux_msg_queue_msgctl),
7072 LSM_HOOK_INIT(msg_queue_msgsnd, selinux_msg_queue_msgsnd),
7073 LSM_HOOK_INIT(msg_queue_msgrcv, selinux_msg_queue_msgrcv),
7074
7075 LSM_HOOK_INIT(shm_associate, selinux_shm_associate),
7076 LSM_HOOK_INIT(shm_shmctl, selinux_shm_shmctl),
7077 LSM_HOOK_INIT(shm_shmat, selinux_shm_shmat),
7078
7079 LSM_HOOK_INIT(sem_associate, selinux_sem_associate),
7080 LSM_HOOK_INIT(sem_semctl, selinux_sem_semctl),
7081 LSM_HOOK_INIT(sem_semop, selinux_sem_semop),
7082
7083 LSM_HOOK_INIT(d_instantiate, selinux_d_instantiate),
7084
7085 LSM_HOOK_INIT(getprocattr, selinux_getprocattr),
7086 LSM_HOOK_INIT(setprocattr, selinux_setprocattr),
7087
7088 LSM_HOOK_INIT(ismaclabel, selinux_ismaclabel),
7089 LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid),
7090 LSM_HOOK_INIT(release_secctx, selinux_release_secctx),
7091 LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx),
7092 LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx),
7093 LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx),
7094
7095 LSM_HOOK_INIT(unix_stream_connect, selinux_socket_unix_stream_connect),
7096 LSM_HOOK_INIT(unix_may_send, selinux_socket_unix_may_send),
7097
7098 LSM_HOOK_INIT(socket_create, selinux_socket_create),
7099 LSM_HOOK_INIT(socket_post_create, selinux_socket_post_create),
7100 LSM_HOOK_INIT(socket_socketpair, selinux_socket_socketpair),
7101 LSM_HOOK_INIT(socket_bind, selinux_socket_bind),
7102 LSM_HOOK_INIT(socket_connect, selinux_socket_connect),
7103 LSM_HOOK_INIT(socket_listen, selinux_socket_listen),
7104 LSM_HOOK_INIT(socket_accept, selinux_socket_accept),
7105 LSM_HOOK_INIT(socket_sendmsg, selinux_socket_sendmsg),
7106 LSM_HOOK_INIT(socket_recvmsg, selinux_socket_recvmsg),
7107 LSM_HOOK_INIT(socket_getsockname, selinux_socket_getsockname),
7108 LSM_HOOK_INIT(socket_getpeername, selinux_socket_getpeername),
7109 LSM_HOOK_INIT(socket_getsockopt, selinux_socket_getsockopt),
7110 LSM_HOOK_INIT(socket_setsockopt, selinux_socket_setsockopt),
7111 LSM_HOOK_INIT(socket_shutdown, selinux_socket_shutdown),
7112 LSM_HOOK_INIT(socket_sock_rcv_skb, selinux_socket_sock_rcv_skb),
7113 LSM_HOOK_INIT(socket_getpeersec_stream,
7114 selinux_socket_getpeersec_stream),
7115 LSM_HOOK_INIT(socket_getpeersec_dgram, selinux_socket_getpeersec_dgram),
7116 LSM_HOOK_INIT(sk_free_security, selinux_sk_free_security),
7117 LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security),
7118 LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid),
7119 LSM_HOOK_INIT(sock_graft, selinux_sock_graft),
7120 LSM_HOOK_INIT(sctp_assoc_request, selinux_sctp_assoc_request),
7121 LSM_HOOK_INIT(sctp_sk_clone, selinux_sctp_sk_clone),
7122 LSM_HOOK_INIT(sctp_bind_connect, selinux_sctp_bind_connect),
7123 LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request),
7124 LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone),
7125 LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established),
7126 LSM_HOOK_INIT(secmark_relabel_packet, selinux_secmark_relabel_packet),
7127 LSM_HOOK_INIT(secmark_refcount_inc, selinux_secmark_refcount_inc),
7128 LSM_HOOK_INIT(secmark_refcount_dec, selinux_secmark_refcount_dec),
7129 LSM_HOOK_INIT(req_classify_flow, selinux_req_classify_flow),
7130 LSM_HOOK_INIT(tun_dev_free_security, selinux_tun_dev_free_security),
7131 LSM_HOOK_INIT(tun_dev_create, selinux_tun_dev_create),
7132 LSM_HOOK_INIT(tun_dev_attach_queue, selinux_tun_dev_attach_queue),
7133 LSM_HOOK_INIT(tun_dev_attach, selinux_tun_dev_attach),
7134 LSM_HOOK_INIT(tun_dev_open, selinux_tun_dev_open),
7135 #ifdef CONFIG_SECURITY_INFINIBAND
7136 LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access),
7137 LSM_HOOK_INIT(ib_endport_manage_subnet,
7138 selinux_ib_endport_manage_subnet),
7139 LSM_HOOK_INIT(ib_free_security, selinux_ib_free_security),
7140 #endif
7141 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7142 LSM_HOOK_INIT(xfrm_policy_free_security, selinux_xfrm_policy_free),
7143 LSM_HOOK_INIT(xfrm_policy_delete_security, selinux_xfrm_policy_delete),
7144 LSM_HOOK_INIT(xfrm_state_free_security, selinux_xfrm_state_free),
7145 LSM_HOOK_INIT(xfrm_state_delete_security, selinux_xfrm_state_delete),
7146 LSM_HOOK_INIT(xfrm_policy_lookup, selinux_xfrm_policy_lookup),
7147 LSM_HOOK_INIT(xfrm_state_pol_flow_match,
7148 selinux_xfrm_state_pol_flow_match),
7149 LSM_HOOK_INIT(xfrm_decode_session, selinux_xfrm_decode_session),
7150 #endif
7151
7152 #ifdef CONFIG_KEYS
7153 LSM_HOOK_INIT(key_free, selinux_key_free),
7154 LSM_HOOK_INIT(key_permission, selinux_key_permission),
7155 LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity),
7156 #ifdef CONFIG_KEY_NOTIFICATIONS
7157 LSM_HOOK_INIT(watch_key, selinux_watch_key),
7158 #endif
7159 #endif
7160
7161 #ifdef CONFIG_AUDIT
7162 LSM_HOOK_INIT(audit_rule_known, selinux_audit_rule_known),
7163 LSM_HOOK_INIT(audit_rule_match, selinux_audit_rule_match),
7164 LSM_HOOK_INIT(audit_rule_free, selinux_audit_rule_free),
7165 #endif
7166
7167 #ifdef CONFIG_BPF_SYSCALL
7168 LSM_HOOK_INIT(bpf, selinux_bpf),
7169 LSM_HOOK_INIT(bpf_map, selinux_bpf_map),
7170 LSM_HOOK_INIT(bpf_prog, selinux_bpf_prog),
7171 LSM_HOOK_INIT(bpf_map_free_security, selinux_bpf_map_free),
7172 LSM_HOOK_INIT(bpf_prog_free_security, selinux_bpf_prog_free),
7173 #endif
7174
7175 #ifdef CONFIG_PERF_EVENTS
7176 LSM_HOOK_INIT(perf_event_open, selinux_perf_event_open),
7177 LSM_HOOK_INIT(perf_event_free, selinux_perf_event_free),
7178 LSM_HOOK_INIT(perf_event_read, selinux_perf_event_read),
7179 LSM_HOOK_INIT(perf_event_write, selinux_perf_event_write),
7180 #endif
7181
7182 LSM_HOOK_INIT(locked_down, selinux_lockdown),
7183
7184 /*
7185 * PUT "CLONING" (ACCESSING + ALLOCATING) HOOKS HERE
7186 */
7187 LSM_HOOK_INIT(fs_context_dup, selinux_fs_context_dup),
7188 LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param),
7189 LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts),
7190 LSM_HOOK_INIT(sb_add_mnt_opt, selinux_add_mnt_opt),
7191 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7192 LSM_HOOK_INIT(xfrm_policy_clone_security, selinux_xfrm_policy_clone),
7193 #endif
7194
7195 /*
7196 * PUT "ALLOCATING" HOOKS HERE
7197 */
7198 LSM_HOOK_INIT(msg_msg_alloc_security, selinux_msg_msg_alloc_security),
7199 LSM_HOOK_INIT(msg_queue_alloc_security,
7200 selinux_msg_queue_alloc_security),
7201 LSM_HOOK_INIT(shm_alloc_security, selinux_shm_alloc_security),
7202 LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security),
7203 LSM_HOOK_INIT(inode_alloc_security, selinux_inode_alloc_security),
7204 LSM_HOOK_INIT(sem_alloc_security, selinux_sem_alloc_security),
7205 LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx),
7206 LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx),
7207 LSM_HOOK_INIT(sk_alloc_security, selinux_sk_alloc_security),
7208 LSM_HOOK_INIT(tun_dev_alloc_security, selinux_tun_dev_alloc_security),
7209 #ifdef CONFIG_SECURITY_INFINIBAND
7210 LSM_HOOK_INIT(ib_alloc_security, selinux_ib_alloc_security),
7211 #endif
7212 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7213 LSM_HOOK_INIT(xfrm_policy_alloc_security, selinux_xfrm_policy_alloc),
7214 LSM_HOOK_INIT(xfrm_state_alloc, selinux_xfrm_state_alloc),
7215 LSM_HOOK_INIT(xfrm_state_alloc_acquire,
7216 selinux_xfrm_state_alloc_acquire),
7217 #endif
7218 #ifdef CONFIG_KEYS
7219 LSM_HOOK_INIT(key_alloc, selinux_key_alloc),
7220 #endif
7221 #ifdef CONFIG_AUDIT
7222 LSM_HOOK_INIT(audit_rule_init, selinux_audit_rule_init),
7223 #endif
7224 #ifdef CONFIG_BPF_SYSCALL
7225 LSM_HOOK_INIT(bpf_map_alloc_security, selinux_bpf_map_alloc),
7226 LSM_HOOK_INIT(bpf_prog_alloc_security, selinux_bpf_prog_alloc),
7227 #endif
7228 #ifdef CONFIG_PERF_EVENTS
7229 LSM_HOOK_INIT(perf_event_alloc, selinux_perf_event_alloc),
7230 #endif
7231 };
7232
selinux_init(void)7233 static __init int selinux_init(void)
7234 {
7235 pr_info("SELinux: Initializing.\n");
7236
7237 memset(&selinux_state, 0, sizeof(selinux_state));
7238 enforcing_set(&selinux_state, selinux_enforcing_boot);
7239 checkreqprot_set(&selinux_state, selinux_checkreqprot_boot);
7240 selinux_avc_init(&selinux_state.avc);
7241 mutex_init(&selinux_state.status_lock);
7242 mutex_init(&selinux_state.policy_mutex);
7243
7244 /* Set the security state for the initial task. */
7245 cred_init_security();
7246
7247 default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
7248
7249 avc_init();
7250
7251 avtab_cache_init();
7252
7253 ebitmap_cache_init();
7254
7255 hashtab_cache_init();
7256
7257 security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux");
7258
7259 if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
7260 panic("SELinux: Unable to register AVC netcache callback\n");
7261
7262 if (avc_add_callback(selinux_lsm_notifier_avc_callback, AVC_CALLBACK_RESET))
7263 panic("SELinux: Unable to register AVC LSM notifier callback\n");
7264
7265 if (selinux_enforcing_boot)
7266 pr_debug("SELinux: Starting in enforcing mode\n");
7267 else
7268 pr_debug("SELinux: Starting in permissive mode\n");
7269
7270 fs_validate_description("selinux", selinux_fs_parameters);
7271
7272 return 0;
7273 }
7274
delayed_superblock_init(struct super_block * sb,void * unused)7275 static void delayed_superblock_init(struct super_block *sb, void *unused)
7276 {
7277 selinux_set_mnt_opts(sb, NULL, 0, NULL);
7278 }
7279
selinux_complete_init(void)7280 void selinux_complete_init(void)
7281 {
7282 pr_debug("SELinux: Completing initialization.\n");
7283
7284 /* Set up any superblocks initialized prior to the policy load. */
7285 pr_debug("SELinux: Setting up existing superblocks.\n");
7286 iterate_supers(delayed_superblock_init, NULL);
7287 }
7288
7289 /* SELinux requires early initialization in order to label
7290 all processes and objects when they are created. */
7291 DEFINE_LSM(selinux) = {
7292 .name = "selinux",
7293 .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
7294 .enabled = &selinux_enabled_boot,
7295 .blobs = &selinux_blob_sizes,
7296 .init = selinux_init,
7297 };
7298
7299 #if defined(CONFIG_NETFILTER)
7300
7301 static const struct nf_hook_ops selinux_nf_ops[] = {
7302 {
7303 .hook = selinux_ipv4_postroute,
7304 .pf = NFPROTO_IPV4,
7305 .hooknum = NF_INET_POST_ROUTING,
7306 .priority = NF_IP_PRI_SELINUX_LAST,
7307 },
7308 {
7309 .hook = selinux_ipv4_forward,
7310 .pf = NFPROTO_IPV4,
7311 .hooknum = NF_INET_FORWARD,
7312 .priority = NF_IP_PRI_SELINUX_FIRST,
7313 },
7314 {
7315 .hook = selinux_ipv4_output,
7316 .pf = NFPROTO_IPV4,
7317 .hooknum = NF_INET_LOCAL_OUT,
7318 .priority = NF_IP_PRI_SELINUX_FIRST,
7319 },
7320 #if IS_ENABLED(CONFIG_IPV6)
7321 {
7322 .hook = selinux_ipv6_postroute,
7323 .pf = NFPROTO_IPV6,
7324 .hooknum = NF_INET_POST_ROUTING,
7325 .priority = NF_IP6_PRI_SELINUX_LAST,
7326 },
7327 {
7328 .hook = selinux_ipv6_forward,
7329 .pf = NFPROTO_IPV6,
7330 .hooknum = NF_INET_FORWARD,
7331 .priority = NF_IP6_PRI_SELINUX_FIRST,
7332 },
7333 {
7334 .hook = selinux_ipv6_output,
7335 .pf = NFPROTO_IPV6,
7336 .hooknum = NF_INET_LOCAL_OUT,
7337 .priority = NF_IP6_PRI_SELINUX_FIRST,
7338 },
7339 #endif /* IPV6 */
7340 };
7341
selinux_nf_register(struct net * net)7342 static int __net_init selinux_nf_register(struct net *net)
7343 {
7344 return nf_register_net_hooks(net, selinux_nf_ops,
7345 ARRAY_SIZE(selinux_nf_ops));
7346 }
7347
selinux_nf_unregister(struct net * net)7348 static void __net_exit selinux_nf_unregister(struct net *net)
7349 {
7350 nf_unregister_net_hooks(net, selinux_nf_ops,
7351 ARRAY_SIZE(selinux_nf_ops));
7352 }
7353
7354 static struct pernet_operations selinux_net_ops = {
7355 .init = selinux_nf_register,
7356 .exit = selinux_nf_unregister,
7357 };
7358
selinux_nf_ip_init(void)7359 static int __init selinux_nf_ip_init(void)
7360 {
7361 int err;
7362
7363 if (!selinux_enabled_boot)
7364 return 0;
7365
7366 pr_debug("SELinux: Registering netfilter hooks\n");
7367
7368 err = register_pernet_subsys(&selinux_net_ops);
7369 if (err)
7370 panic("SELinux: register_pernet_subsys: error %d\n", err);
7371
7372 return 0;
7373 }
7374 __initcall(selinux_nf_ip_init);
7375
7376 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
selinux_nf_ip_exit(void)7377 static void selinux_nf_ip_exit(void)
7378 {
7379 pr_debug("SELinux: Unregistering netfilter hooks\n");
7380
7381 unregister_pernet_subsys(&selinux_net_ops);
7382 }
7383 #endif
7384
7385 #else /* CONFIG_NETFILTER */
7386
7387 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
7388 #define selinux_nf_ip_exit()
7389 #endif
7390
7391 #endif /* CONFIG_NETFILTER */
7392
7393 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
selinux_disable(struct selinux_state * state)7394 int selinux_disable(struct selinux_state *state)
7395 {
7396 if (selinux_initialized(state)) {
7397 /* Not permitted after initial policy load. */
7398 return -EINVAL;
7399 }
7400
7401 if (selinux_disabled(state)) {
7402 /* Only do this once. */
7403 return -EINVAL;
7404 }
7405
7406 selinux_mark_disabled(state);
7407
7408 pr_info("SELinux: Disabled at runtime.\n");
7409
7410 /*
7411 * Unregister netfilter hooks.
7412 * Must be done before security_delete_hooks() to avoid breaking
7413 * runtime disable.
7414 */
7415 selinux_nf_ip_exit();
7416
7417 security_delete_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks));
7418
7419 /* Try to destroy the avc node cache */
7420 avc_disable();
7421
7422 /* Unregister selinuxfs. */
7423 exit_sel_fs();
7424
7425 return 0;
7426 }
7427 #endif
7428