1 /*
2 * AppArmor security module
3 *
4 * This file contains AppArmor LSM hooks.
5 *
6 * Copyright (C) 1998-2008 Novell/SUSE
7 * Copyright 2009-2010 Canonical Ltd.
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation, version 2 of the
12 * License.
13 */
14
15 #include <linux/lsm_hooks.h>
16 #include <linux/moduleparam.h>
17 #include <linux/mm.h>
18 #include <linux/mman.h>
19 #include <linux/mount.h>
20 #include <linux/namei.h>
21 #include <linux/ptrace.h>
22 #include <linux/ctype.h>
23 #include <linux/sysctl.h>
24 #include <linux/audit.h>
25 #include <linux/user_namespace.h>
26 #include <net/sock.h>
27
28 #include "include/apparmor.h"
29 #include "include/apparmorfs.h"
30 #include "include/audit.h"
31 #include "include/capability.h"
32 #include "include/cred.h"
33 #include "include/file.h"
34 #include "include/ipc.h"
35 #include "include/net.h"
36 #include "include/path.h"
37 #include "include/label.h"
38 #include "include/policy.h"
39 #include "include/policy_ns.h"
40 #include "include/procattr.h"
41 #include "include/mount.h"
42 #include "include/secid.h"
43
44 /* Flag indicating whether initialization completed */
45 int apparmor_initialized;
46
47 DEFINE_PER_CPU(struct aa_buffers, aa_buffers);
48
49
50 /*
51 * LSM hook functions
52 */
53
54 /*
55 * put the associated labels
56 */
apparmor_cred_free(struct cred * cred)57 static void apparmor_cred_free(struct cred *cred)
58 {
59 aa_put_label(cred_label(cred));
60 cred_label(cred) = NULL;
61 }
62
63 /*
64 * allocate the apparmor part of blank credentials
65 */
apparmor_cred_alloc_blank(struct cred * cred,gfp_t gfp)66 static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
67 {
68 cred_label(cred) = NULL;
69 return 0;
70 }
71
72 /*
73 * prepare new cred label for modification by prepare_cred block
74 */
apparmor_cred_prepare(struct cred * new,const struct cred * old,gfp_t gfp)75 static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
76 gfp_t gfp)
77 {
78 cred_label(new) = aa_get_newest_label(cred_label(old));
79 return 0;
80 }
81
82 /*
83 * transfer the apparmor data to a blank set of creds
84 */
apparmor_cred_transfer(struct cred * new,const struct cred * old)85 static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
86 {
87 cred_label(new) = aa_get_newest_label(cred_label(old));
88 }
89
apparmor_task_free(struct task_struct * task)90 static void apparmor_task_free(struct task_struct *task)
91 {
92
93 aa_free_task_ctx(task_ctx(task));
94 task_ctx(task) = NULL;
95 }
96
apparmor_task_alloc(struct task_struct * task,unsigned long clone_flags)97 static int apparmor_task_alloc(struct task_struct *task,
98 unsigned long clone_flags)
99 {
100 struct aa_task_ctx *new = aa_alloc_task_ctx(GFP_KERNEL);
101
102 if (!new)
103 return -ENOMEM;
104
105 aa_dup_task_ctx(new, task_ctx(current));
106 task_ctx(task) = new;
107
108 return 0;
109 }
110
apparmor_ptrace_access_check(struct task_struct * child,unsigned int mode)111 static int apparmor_ptrace_access_check(struct task_struct *child,
112 unsigned int mode)
113 {
114 struct aa_label *tracer, *tracee;
115 int error;
116
117 tracer = __begin_current_label_crit_section();
118 tracee = aa_get_task_label(child);
119 error = aa_may_ptrace(tracer, tracee,
120 (mode & PTRACE_MODE_READ) ? AA_PTRACE_READ
121 : AA_PTRACE_TRACE);
122 aa_put_label(tracee);
123 __end_current_label_crit_section(tracer);
124
125 return error;
126 }
127
apparmor_ptrace_traceme(struct task_struct * parent)128 static int apparmor_ptrace_traceme(struct task_struct *parent)
129 {
130 struct aa_label *tracer, *tracee;
131 int error;
132
133 tracee = __begin_current_label_crit_section();
134 tracer = aa_get_task_label(parent);
135 error = aa_may_ptrace(tracer, tracee, AA_PTRACE_TRACE);
136 aa_put_label(tracer);
137 __end_current_label_crit_section(tracee);
138
139 return error;
140 }
141
142 /* Derived from security/commoncap.c:cap_capget */
apparmor_capget(struct task_struct * target,kernel_cap_t * effective,kernel_cap_t * inheritable,kernel_cap_t * permitted)143 static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
144 kernel_cap_t *inheritable, kernel_cap_t *permitted)
145 {
146 struct aa_label *label;
147 const struct cred *cred;
148
149 rcu_read_lock();
150 cred = __task_cred(target);
151 label = aa_get_newest_cred_label(cred);
152
153 /*
154 * cap_capget is stacked ahead of this and will
155 * initialize effective and permitted.
156 */
157 if (!unconfined(label)) {
158 struct aa_profile *profile;
159 struct label_it i;
160
161 label_for_each_confined(i, label, profile) {
162 if (COMPLAIN_MODE(profile))
163 continue;
164 *effective = cap_intersect(*effective,
165 profile->caps.allow);
166 *permitted = cap_intersect(*permitted,
167 profile->caps.allow);
168 }
169 }
170 rcu_read_unlock();
171 aa_put_label(label);
172
173 return 0;
174 }
175
apparmor_capable(const struct cred * cred,struct user_namespace * ns,int cap,unsigned int opts)176 static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
177 int cap, unsigned int opts)
178 {
179 struct aa_label *label;
180 int error = 0;
181
182 label = aa_get_newest_cred_label(cred);
183 if (!unconfined(label))
184 error = aa_capable(label, cap, opts);
185 aa_put_label(label);
186
187 return error;
188 }
189
190 /**
191 * common_perm - basic common permission check wrapper fn for paths
192 * @op: operation being checked
193 * @path: path to check permission of (NOT NULL)
194 * @mask: requested permissions mask
195 * @cond: conditional info for the permission request (NOT NULL)
196 *
197 * Returns: %0 else error code if error or permission denied
198 */
common_perm(const char * op,const struct path * path,u32 mask,struct path_cond * cond)199 static int common_perm(const char *op, const struct path *path, u32 mask,
200 struct path_cond *cond)
201 {
202 struct aa_label *label;
203 int error = 0;
204
205 label = __begin_current_label_crit_section();
206 if (!unconfined(label))
207 error = aa_path_perm(op, label, path, 0, mask, cond);
208 __end_current_label_crit_section(label);
209
210 return error;
211 }
212
213 /**
214 * common_perm_cond - common permission wrapper around inode cond
215 * @op: operation being checked
216 * @path: location to check (NOT NULL)
217 * @mask: requested permissions mask
218 *
219 * Returns: %0 else error code if error or permission denied
220 */
common_perm_cond(const char * op,const struct path * path,u32 mask)221 static int common_perm_cond(const char *op, const struct path *path, u32 mask)
222 {
223 struct path_cond cond = { d_backing_inode(path->dentry)->i_uid,
224 d_backing_inode(path->dentry)->i_mode
225 };
226
227 if (!path_mediated_fs(path->dentry))
228 return 0;
229
230 return common_perm(op, path, mask, &cond);
231 }
232
233 /**
234 * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
235 * @op: operation being checked
236 * @dir: directory of the dentry (NOT NULL)
237 * @dentry: dentry to check (NOT NULL)
238 * @mask: requested permissions mask
239 * @cond: conditional info for the permission request (NOT NULL)
240 *
241 * Returns: %0 else error code if error or permission denied
242 */
common_perm_dir_dentry(const char * op,const struct path * dir,struct dentry * dentry,u32 mask,struct path_cond * cond)243 static int common_perm_dir_dentry(const char *op, const struct path *dir,
244 struct dentry *dentry, u32 mask,
245 struct path_cond *cond)
246 {
247 struct path path = { .mnt = dir->mnt, .dentry = dentry };
248
249 return common_perm(op, &path, mask, cond);
250 }
251
252 /**
253 * common_perm_rm - common permission wrapper for operations doing rm
254 * @op: operation being checked
255 * @dir: directory that the dentry is in (NOT NULL)
256 * @dentry: dentry being rm'd (NOT NULL)
257 * @mask: requested permission mask
258 *
259 * Returns: %0 else error code if error or permission denied
260 */
common_perm_rm(const char * op,const struct path * dir,struct dentry * dentry,u32 mask)261 static int common_perm_rm(const char *op, const struct path *dir,
262 struct dentry *dentry, u32 mask)
263 {
264 struct inode *inode = d_backing_inode(dentry);
265 struct path_cond cond = { };
266
267 if (!inode || !path_mediated_fs(dentry))
268 return 0;
269
270 cond.uid = inode->i_uid;
271 cond.mode = inode->i_mode;
272
273 return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
274 }
275
276 /**
277 * common_perm_create - common permission wrapper for operations doing create
278 * @op: operation being checked
279 * @dir: directory that dentry will be created in (NOT NULL)
280 * @dentry: dentry to create (NOT NULL)
281 * @mask: request permission mask
282 * @mode: created file mode
283 *
284 * Returns: %0 else error code if error or permission denied
285 */
common_perm_create(const char * op,const struct path * dir,struct dentry * dentry,u32 mask,umode_t mode)286 static int common_perm_create(const char *op, const struct path *dir,
287 struct dentry *dentry, u32 mask, umode_t mode)
288 {
289 struct path_cond cond = { current_fsuid(), mode };
290
291 if (!path_mediated_fs(dir->dentry))
292 return 0;
293
294 return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
295 }
296
apparmor_path_unlink(const struct path * dir,struct dentry * dentry)297 static int apparmor_path_unlink(const struct path *dir, struct dentry *dentry)
298 {
299 return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
300 }
301
apparmor_path_mkdir(const struct path * dir,struct dentry * dentry,umode_t mode)302 static int apparmor_path_mkdir(const struct path *dir, struct dentry *dentry,
303 umode_t mode)
304 {
305 return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
306 S_IFDIR);
307 }
308
apparmor_path_rmdir(const struct path * dir,struct dentry * dentry)309 static int apparmor_path_rmdir(const struct path *dir, struct dentry *dentry)
310 {
311 return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
312 }
313
apparmor_path_mknod(const struct path * dir,struct dentry * dentry,umode_t mode,unsigned int dev)314 static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry,
315 umode_t mode, unsigned int dev)
316 {
317 return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
318 }
319
apparmor_path_truncate(const struct path * path)320 static int apparmor_path_truncate(const struct path *path)
321 {
322 return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_SETATTR);
323 }
324
apparmor_path_symlink(const struct path * dir,struct dentry * dentry,const char * old_name)325 static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry,
326 const char *old_name)
327 {
328 return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
329 S_IFLNK);
330 }
331
apparmor_path_link(struct dentry * old_dentry,const struct path * new_dir,struct dentry * new_dentry)332 static int apparmor_path_link(struct dentry *old_dentry, const struct path *new_dir,
333 struct dentry *new_dentry)
334 {
335 struct aa_label *label;
336 int error = 0;
337
338 if (!path_mediated_fs(old_dentry))
339 return 0;
340
341 label = begin_current_label_crit_section();
342 if (!unconfined(label))
343 error = aa_path_link(label, old_dentry, new_dir, new_dentry);
344 end_current_label_crit_section(label);
345
346 return error;
347 }
348
apparmor_path_rename(const struct path * old_dir,struct dentry * old_dentry,const struct path * new_dir,struct dentry * new_dentry)349 static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_dentry,
350 const struct path *new_dir, struct dentry *new_dentry)
351 {
352 struct aa_label *label;
353 int error = 0;
354
355 if (!path_mediated_fs(old_dentry))
356 return 0;
357
358 label = begin_current_label_crit_section();
359 if (!unconfined(label)) {
360 struct path old_path = { .mnt = old_dir->mnt,
361 .dentry = old_dentry };
362 struct path new_path = { .mnt = new_dir->mnt,
363 .dentry = new_dentry };
364 struct path_cond cond = { d_backing_inode(old_dentry)->i_uid,
365 d_backing_inode(old_dentry)->i_mode
366 };
367
368 error = aa_path_perm(OP_RENAME_SRC, label, &old_path, 0,
369 MAY_READ | AA_MAY_GETATTR | MAY_WRITE |
370 AA_MAY_SETATTR | AA_MAY_DELETE,
371 &cond);
372 if (!error)
373 error = aa_path_perm(OP_RENAME_DEST, label, &new_path,
374 0, MAY_WRITE | AA_MAY_SETATTR |
375 AA_MAY_CREATE, &cond);
376
377 }
378 end_current_label_crit_section(label);
379
380 return error;
381 }
382
apparmor_path_chmod(const struct path * path,umode_t mode)383 static int apparmor_path_chmod(const struct path *path, umode_t mode)
384 {
385 return common_perm_cond(OP_CHMOD, path, AA_MAY_CHMOD);
386 }
387
apparmor_path_chown(const struct path * path,kuid_t uid,kgid_t gid)388 static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
389 {
390 return common_perm_cond(OP_CHOWN, path, AA_MAY_CHOWN);
391 }
392
apparmor_inode_getattr(const struct path * path)393 static int apparmor_inode_getattr(const struct path *path)
394 {
395 return common_perm_cond(OP_GETATTR, path, AA_MAY_GETATTR);
396 }
397
apparmor_file_open(struct file * file)398 static int apparmor_file_open(struct file *file)
399 {
400 struct aa_file_ctx *fctx = file_ctx(file);
401 struct aa_label *label;
402 int error = 0;
403
404 if (!path_mediated_fs(file->f_path.dentry))
405 return 0;
406
407 /* If in exec, permission is handled by bprm hooks.
408 * Cache permissions granted by the previous exec check, with
409 * implicit read and executable mmap which are required to
410 * actually execute the image.
411 */
412 if (current->in_execve) {
413 fctx->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
414 return 0;
415 }
416
417 label = aa_get_newest_cred_label(file->f_cred);
418 if (!unconfined(label)) {
419 struct inode *inode = file_inode(file);
420 struct path_cond cond = { inode->i_uid, inode->i_mode };
421
422 error = aa_path_perm(OP_OPEN, label, &file->f_path, 0,
423 aa_map_file_to_perms(file), &cond);
424 /* todo cache full allowed permissions set and state */
425 fctx->allow = aa_map_file_to_perms(file);
426 }
427 aa_put_label(label);
428
429 return error;
430 }
431
apparmor_file_alloc_security(struct file * file)432 static int apparmor_file_alloc_security(struct file *file)
433 {
434 int error = 0;
435
436 /* freed by apparmor_file_free_security */
437 struct aa_label *label = begin_current_label_crit_section();
438 file->f_security = aa_alloc_file_ctx(label, GFP_KERNEL);
439 if (!file_ctx(file))
440 error = -ENOMEM;
441 end_current_label_crit_section(label);
442
443 return error;
444 }
445
apparmor_file_free_security(struct file * file)446 static void apparmor_file_free_security(struct file *file)
447 {
448 aa_free_file_ctx(file_ctx(file));
449 }
450
common_file_perm(const char * op,struct file * file,u32 mask)451 static int common_file_perm(const char *op, struct file *file, u32 mask)
452 {
453 struct aa_label *label;
454 int error = 0;
455
456 /* don't reaudit files closed during inheritance */
457 if (file->f_path.dentry == aa_null.dentry)
458 return -EACCES;
459
460 label = __begin_current_label_crit_section();
461 error = aa_file_perm(op, label, file, mask);
462 __end_current_label_crit_section(label);
463
464 return error;
465 }
466
apparmor_file_receive(struct file * file)467 static int apparmor_file_receive(struct file *file)
468 {
469 return common_file_perm(OP_FRECEIVE, file, aa_map_file_to_perms(file));
470 }
471
apparmor_file_permission(struct file * file,int mask)472 static int apparmor_file_permission(struct file *file, int mask)
473 {
474 return common_file_perm(OP_FPERM, file, mask);
475 }
476
apparmor_file_lock(struct file * file,unsigned int cmd)477 static int apparmor_file_lock(struct file *file, unsigned int cmd)
478 {
479 u32 mask = AA_MAY_LOCK;
480
481 if (cmd == F_WRLCK)
482 mask |= MAY_WRITE;
483
484 return common_file_perm(OP_FLOCK, file, mask);
485 }
486
common_mmap(const char * op,struct file * file,unsigned long prot,unsigned long flags)487 static int common_mmap(const char *op, struct file *file, unsigned long prot,
488 unsigned long flags)
489 {
490 int mask = 0;
491
492 if (!file || !file_ctx(file))
493 return 0;
494
495 if (prot & PROT_READ)
496 mask |= MAY_READ;
497 /*
498 * Private mappings don't require write perms since they don't
499 * write back to the files
500 */
501 if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
502 mask |= MAY_WRITE;
503 if (prot & PROT_EXEC)
504 mask |= AA_EXEC_MMAP;
505
506 return common_file_perm(op, file, mask);
507 }
508
apparmor_mmap_file(struct file * file,unsigned long reqprot,unsigned long prot,unsigned long flags)509 static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
510 unsigned long prot, unsigned long flags)
511 {
512 return common_mmap(OP_FMMAP, file, prot, flags);
513 }
514
apparmor_file_mprotect(struct vm_area_struct * vma,unsigned long reqprot,unsigned long prot)515 static int apparmor_file_mprotect(struct vm_area_struct *vma,
516 unsigned long reqprot, unsigned long prot)
517 {
518 return common_mmap(OP_FMPROT, vma->vm_file, prot,
519 !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0);
520 }
521
apparmor_sb_mount(const char * dev_name,const struct path * path,const char * type,unsigned long flags,void * data)522 static int apparmor_sb_mount(const char *dev_name, const struct path *path,
523 const char *type, unsigned long flags, void *data)
524 {
525 struct aa_label *label;
526 int error = 0;
527
528 /* Discard magic */
529 if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
530 flags &= ~MS_MGC_MSK;
531
532 flags &= ~AA_MS_IGNORE_MASK;
533
534 label = __begin_current_label_crit_section();
535 if (!unconfined(label)) {
536 if (flags & MS_REMOUNT)
537 error = aa_remount(label, path, flags, data);
538 else if (flags & MS_BIND)
539 error = aa_bind_mount(label, path, dev_name, flags);
540 else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE |
541 MS_UNBINDABLE))
542 error = aa_mount_change_type(label, path, flags);
543 else if (flags & MS_MOVE)
544 error = aa_move_mount(label, path, dev_name);
545 else
546 error = aa_new_mount(label, dev_name, path, type,
547 flags, data);
548 }
549 __end_current_label_crit_section(label);
550
551 return error;
552 }
553
apparmor_sb_umount(struct vfsmount * mnt,int flags)554 static int apparmor_sb_umount(struct vfsmount *mnt, int flags)
555 {
556 struct aa_label *label;
557 int error = 0;
558
559 label = __begin_current_label_crit_section();
560 if (!unconfined(label))
561 error = aa_umount(label, mnt, flags);
562 __end_current_label_crit_section(label);
563
564 return error;
565 }
566
apparmor_sb_pivotroot(const struct path * old_path,const struct path * new_path)567 static int apparmor_sb_pivotroot(const struct path *old_path,
568 const struct path *new_path)
569 {
570 struct aa_label *label;
571 int error = 0;
572
573 label = aa_get_current_label();
574 if (!unconfined(label))
575 error = aa_pivotroot(label, old_path, new_path);
576 aa_put_label(label);
577
578 return error;
579 }
580
apparmor_getprocattr(struct task_struct * task,char * name,char ** value)581 static int apparmor_getprocattr(struct task_struct *task, char *name,
582 char **value)
583 {
584 int error = -ENOENT;
585 /* released below */
586 const struct cred *cred = get_task_cred(task);
587 struct aa_task_ctx *ctx = task_ctx(current);
588 struct aa_label *label = NULL;
589
590 if (strcmp(name, "current") == 0)
591 label = aa_get_newest_label(cred_label(cred));
592 else if (strcmp(name, "prev") == 0 && ctx->previous)
593 label = aa_get_newest_label(ctx->previous);
594 else if (strcmp(name, "exec") == 0 && ctx->onexec)
595 label = aa_get_newest_label(ctx->onexec);
596 else
597 error = -EINVAL;
598
599 if (label)
600 error = aa_getprocattr(label, value);
601
602 aa_put_label(label);
603 put_cred(cred);
604
605 return error;
606 }
607
apparmor_setprocattr(const char * name,void * value,size_t size)608 static int apparmor_setprocattr(const char *name, void *value,
609 size_t size)
610 {
611 char *command, *largs = NULL, *args = value;
612 size_t arg_size;
613 int error;
614 DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SETPROCATTR);
615
616 if (size == 0)
617 return -EINVAL;
618
619 /* AppArmor requires that the buffer must be null terminated atm */
620 if (args[size - 1] != '\0') {
621 /* null terminate */
622 largs = args = kmalloc(size + 1, GFP_KERNEL);
623 if (!args)
624 return -ENOMEM;
625 memcpy(args, value, size);
626 args[size] = '\0';
627 }
628
629 error = -EINVAL;
630 args = strim(args);
631 command = strsep(&args, " ");
632 if (!args)
633 goto out;
634 args = skip_spaces(args);
635 if (!*args)
636 goto out;
637
638 arg_size = size - (args - (largs ? largs : (char *) value));
639 if (strcmp(name, "current") == 0) {
640 if (strcmp(command, "changehat") == 0) {
641 error = aa_setprocattr_changehat(args, arg_size,
642 AA_CHANGE_NOFLAGS);
643 } else if (strcmp(command, "permhat") == 0) {
644 error = aa_setprocattr_changehat(args, arg_size,
645 AA_CHANGE_TEST);
646 } else if (strcmp(command, "changeprofile") == 0) {
647 error = aa_change_profile(args, AA_CHANGE_NOFLAGS);
648 } else if (strcmp(command, "permprofile") == 0) {
649 error = aa_change_profile(args, AA_CHANGE_TEST);
650 } else if (strcmp(command, "stack") == 0) {
651 error = aa_change_profile(args, AA_CHANGE_STACK);
652 } else
653 goto fail;
654 } else if (strcmp(name, "exec") == 0) {
655 if (strcmp(command, "exec") == 0)
656 error = aa_change_profile(args, AA_CHANGE_ONEXEC);
657 else if (strcmp(command, "stack") == 0)
658 error = aa_change_profile(args, (AA_CHANGE_ONEXEC |
659 AA_CHANGE_STACK));
660 else
661 goto fail;
662 } else
663 /* only support the "current" and "exec" process attributes */
664 goto fail;
665
666 if (!error)
667 error = size;
668 out:
669 kfree(largs);
670 return error;
671
672 fail:
673 aad(&sa)->label = begin_current_label_crit_section();
674 aad(&sa)->info = name;
675 aad(&sa)->error = error = -EINVAL;
676 aa_audit_msg(AUDIT_APPARMOR_DENIED, &sa, NULL);
677 end_current_label_crit_section(aad(&sa)->label);
678 goto out;
679 }
680
681 /**
682 * apparmor_bprm_committing_creds - do task cleanup on committing new creds
683 * @bprm: binprm for the exec (NOT NULL)
684 */
apparmor_bprm_committing_creds(struct linux_binprm * bprm)685 static void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
686 {
687 struct aa_label *label = aa_current_raw_label();
688 struct aa_label *new_label = cred_label(bprm->cred);
689
690 /* bail out if unconfined or not changing profile */
691 if ((new_label->proxy == label->proxy) ||
692 (unconfined(new_label)))
693 return;
694
695 aa_inherit_files(bprm->cred, current->files);
696
697 current->pdeath_signal = 0;
698
699 /* reset soft limits and set hard limits for the new label */
700 __aa_transition_rlimits(label, new_label);
701 }
702
703 /**
704 * apparmor_bprm_committed_cred - do cleanup after new creds committed
705 * @bprm: binprm for the exec (NOT NULL)
706 */
apparmor_bprm_committed_creds(struct linux_binprm * bprm)707 static void apparmor_bprm_committed_creds(struct linux_binprm *bprm)
708 {
709 /* clear out temporary/transitional state from the context */
710 aa_clear_task_ctx_trans(task_ctx(current));
711
712 return;
713 }
714
apparmor_task_getsecid(struct task_struct * p,u32 * secid)715 static void apparmor_task_getsecid(struct task_struct *p, u32 *secid)
716 {
717 struct aa_label *label = aa_get_task_label(p);
718 *secid = label->secid;
719 aa_put_label(label);
720 }
721
apparmor_task_setrlimit(struct task_struct * task,unsigned int resource,struct rlimit * new_rlim)722 static int apparmor_task_setrlimit(struct task_struct *task,
723 unsigned int resource, struct rlimit *new_rlim)
724 {
725 struct aa_label *label = __begin_current_label_crit_section();
726 int error = 0;
727
728 if (!unconfined(label))
729 error = aa_task_setrlimit(label, task, resource, new_rlim);
730 __end_current_label_crit_section(label);
731
732 return error;
733 }
734
apparmor_task_kill(struct task_struct * target,struct siginfo * info,int sig,const struct cred * cred)735 static int apparmor_task_kill(struct task_struct *target, struct siginfo *info,
736 int sig, const struct cred *cred)
737 {
738 struct aa_label *cl, *tl;
739 int error;
740
741 if (cred) {
742 /*
743 * Dealing with USB IO specific behavior
744 */
745 cl = aa_get_newest_cred_label(cred);
746 tl = aa_get_task_label(target);
747 error = aa_may_signal(cl, tl, sig);
748 aa_put_label(cl);
749 aa_put_label(tl);
750 return error;
751 }
752
753 cl = __begin_current_label_crit_section();
754 tl = aa_get_task_label(target);
755 error = aa_may_signal(cl, tl, sig);
756 aa_put_label(tl);
757 __end_current_label_crit_section(cl);
758
759 return error;
760 }
761
762 /**
763 * apparmor_sk_alloc_security - allocate and attach the sk_security field
764 */
apparmor_sk_alloc_security(struct sock * sk,int family,gfp_t flags)765 static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags)
766 {
767 struct aa_sk_ctx *ctx;
768
769 ctx = kzalloc(sizeof(*ctx), flags);
770 if (!ctx)
771 return -ENOMEM;
772
773 SK_CTX(sk) = ctx;
774
775 return 0;
776 }
777
778 /**
779 * apparmor_sk_free_security - free the sk_security field
780 */
apparmor_sk_free_security(struct sock * sk)781 static void apparmor_sk_free_security(struct sock *sk)
782 {
783 struct aa_sk_ctx *ctx = SK_CTX(sk);
784
785 SK_CTX(sk) = NULL;
786 aa_put_label(ctx->label);
787 aa_put_label(ctx->peer);
788 kfree(ctx);
789 }
790
791 /**
792 * apparmor_clone_security - clone the sk_security field
793 */
apparmor_sk_clone_security(const struct sock * sk,struct sock * newsk)794 static void apparmor_sk_clone_security(const struct sock *sk,
795 struct sock *newsk)
796 {
797 struct aa_sk_ctx *ctx = SK_CTX(sk);
798 struct aa_sk_ctx *new = SK_CTX(newsk);
799
800 if (new->label)
801 aa_put_label(new->label);
802 new->label = aa_get_label(ctx->label);
803
804 if (new->peer)
805 aa_put_label(new->peer);
806 new->peer = aa_get_label(ctx->peer);
807 }
808
809 /**
810 * apparmor_socket_create - check perms before creating a new socket
811 */
apparmor_socket_create(int family,int type,int protocol,int kern)812 static int apparmor_socket_create(int family, int type, int protocol, int kern)
813 {
814 struct aa_label *label;
815 int error = 0;
816
817 AA_BUG(in_interrupt());
818
819 label = begin_current_label_crit_section();
820 if (!(kern || unconfined(label)))
821 error = af_select(family,
822 create_perm(label, family, type, protocol),
823 aa_af_perm(label, OP_CREATE, AA_MAY_CREATE,
824 family, type, protocol));
825 end_current_label_crit_section(label);
826
827 return error;
828 }
829
830 /**
831 * apparmor_socket_post_create - setup the per-socket security struct
832 *
833 * Note:
834 * - kernel sockets currently labeled unconfined but we may want to
835 * move to a special kernel label
836 * - socket may not have sk here if created with sock_create_lite or
837 * sock_alloc. These should be accept cases which will be handled in
838 * sock_graft.
839 */
apparmor_socket_post_create(struct socket * sock,int family,int type,int protocol,int kern)840 static int apparmor_socket_post_create(struct socket *sock, int family,
841 int type, int protocol, int kern)
842 {
843 struct aa_label *label;
844
845 if (kern) {
846 struct aa_ns *ns = aa_get_current_ns();
847
848 label = aa_get_label(ns_unconfined(ns));
849 aa_put_ns(ns);
850 } else
851 label = aa_get_current_label();
852
853 if (sock->sk) {
854 struct aa_sk_ctx *ctx = SK_CTX(sock->sk);
855
856 aa_put_label(ctx->label);
857 ctx->label = aa_get_label(label);
858 }
859 aa_put_label(label);
860
861 return 0;
862 }
863
864 /**
865 * apparmor_socket_bind - check perms before bind addr to socket
866 */
apparmor_socket_bind(struct socket * sock,struct sockaddr * address,int addrlen)867 static int apparmor_socket_bind(struct socket *sock,
868 struct sockaddr *address, int addrlen)
869 {
870 AA_BUG(!sock);
871 AA_BUG(!sock->sk);
872 AA_BUG(!address);
873 AA_BUG(in_interrupt());
874
875 return af_select(sock->sk->sk_family,
876 bind_perm(sock, address, addrlen),
877 aa_sk_perm(OP_BIND, AA_MAY_BIND, sock->sk));
878 }
879
880 /**
881 * apparmor_socket_connect - check perms before connecting @sock to @address
882 */
apparmor_socket_connect(struct socket * sock,struct sockaddr * address,int addrlen)883 static int apparmor_socket_connect(struct socket *sock,
884 struct sockaddr *address, int addrlen)
885 {
886 AA_BUG(!sock);
887 AA_BUG(!sock->sk);
888 AA_BUG(!address);
889 AA_BUG(in_interrupt());
890
891 return af_select(sock->sk->sk_family,
892 connect_perm(sock, address, addrlen),
893 aa_sk_perm(OP_CONNECT, AA_MAY_CONNECT, sock->sk));
894 }
895
896 /**
897 * apparmor_socket_list - check perms before allowing listen
898 */
apparmor_socket_listen(struct socket * sock,int backlog)899 static int apparmor_socket_listen(struct socket *sock, int backlog)
900 {
901 AA_BUG(!sock);
902 AA_BUG(!sock->sk);
903 AA_BUG(in_interrupt());
904
905 return af_select(sock->sk->sk_family,
906 listen_perm(sock, backlog),
907 aa_sk_perm(OP_LISTEN, AA_MAY_LISTEN, sock->sk));
908 }
909
910 /**
911 * apparmor_socket_accept - check perms before accepting a new connection.
912 *
913 * Note: while @newsock is created and has some information, the accept
914 * has not been done.
915 */
apparmor_socket_accept(struct socket * sock,struct socket * newsock)916 static int apparmor_socket_accept(struct socket *sock, struct socket *newsock)
917 {
918 AA_BUG(!sock);
919 AA_BUG(!sock->sk);
920 AA_BUG(!newsock);
921 AA_BUG(in_interrupt());
922
923 return af_select(sock->sk->sk_family,
924 accept_perm(sock, newsock),
925 aa_sk_perm(OP_ACCEPT, AA_MAY_ACCEPT, sock->sk));
926 }
927
aa_sock_msg_perm(const char * op,u32 request,struct socket * sock,struct msghdr * msg,int size)928 static int aa_sock_msg_perm(const char *op, u32 request, struct socket *sock,
929 struct msghdr *msg, int size)
930 {
931 AA_BUG(!sock);
932 AA_BUG(!sock->sk);
933 AA_BUG(!msg);
934 AA_BUG(in_interrupt());
935
936 return af_select(sock->sk->sk_family,
937 msg_perm(op, request, sock, msg, size),
938 aa_sk_perm(op, request, sock->sk));
939 }
940
941 /**
942 * apparmor_socket_sendmsg - check perms before sending msg to another socket
943 */
apparmor_socket_sendmsg(struct socket * sock,struct msghdr * msg,int size)944 static int apparmor_socket_sendmsg(struct socket *sock,
945 struct msghdr *msg, int size)
946 {
947 return aa_sock_msg_perm(OP_SENDMSG, AA_MAY_SEND, sock, msg, size);
948 }
949
950 /**
951 * apparmor_socket_recvmsg - check perms before receiving a message
952 */
apparmor_socket_recvmsg(struct socket * sock,struct msghdr * msg,int size,int flags)953 static int apparmor_socket_recvmsg(struct socket *sock,
954 struct msghdr *msg, int size, int flags)
955 {
956 return aa_sock_msg_perm(OP_RECVMSG, AA_MAY_RECEIVE, sock, msg, size);
957 }
958
959 /* revaliation, get/set attr, shutdown */
aa_sock_perm(const char * op,u32 request,struct socket * sock)960 static int aa_sock_perm(const char *op, u32 request, struct socket *sock)
961 {
962 AA_BUG(!sock);
963 AA_BUG(!sock->sk);
964 AA_BUG(in_interrupt());
965
966 return af_select(sock->sk->sk_family,
967 sock_perm(op, request, sock),
968 aa_sk_perm(op, request, sock->sk));
969 }
970
971 /**
972 * apparmor_socket_getsockname - check perms before getting the local address
973 */
apparmor_socket_getsockname(struct socket * sock)974 static int apparmor_socket_getsockname(struct socket *sock)
975 {
976 return aa_sock_perm(OP_GETSOCKNAME, AA_MAY_GETATTR, sock);
977 }
978
979 /**
980 * apparmor_socket_getpeername - check perms before getting remote address
981 */
apparmor_socket_getpeername(struct socket * sock)982 static int apparmor_socket_getpeername(struct socket *sock)
983 {
984 return aa_sock_perm(OP_GETPEERNAME, AA_MAY_GETATTR, sock);
985 }
986
987 /* revaliation, get/set attr, opt */
aa_sock_opt_perm(const char * op,u32 request,struct socket * sock,int level,int optname)988 static int aa_sock_opt_perm(const char *op, u32 request, struct socket *sock,
989 int level, int optname)
990 {
991 AA_BUG(!sock);
992 AA_BUG(!sock->sk);
993 AA_BUG(in_interrupt());
994
995 return af_select(sock->sk->sk_family,
996 opt_perm(op, request, sock, level, optname),
997 aa_sk_perm(op, request, sock->sk));
998 }
999
1000 /**
1001 * apparmor_getsockopt - check perms before getting socket options
1002 */
apparmor_socket_getsockopt(struct socket * sock,int level,int optname)1003 static int apparmor_socket_getsockopt(struct socket *sock, int level,
1004 int optname)
1005 {
1006 return aa_sock_opt_perm(OP_GETSOCKOPT, AA_MAY_GETOPT, sock,
1007 level, optname);
1008 }
1009
1010 /**
1011 * apparmor_setsockopt - check perms before setting socket options
1012 */
apparmor_socket_setsockopt(struct socket * sock,int level,int optname)1013 static int apparmor_socket_setsockopt(struct socket *sock, int level,
1014 int optname)
1015 {
1016 return aa_sock_opt_perm(OP_SETSOCKOPT, AA_MAY_SETOPT, sock,
1017 level, optname);
1018 }
1019
1020 /**
1021 * apparmor_socket_shutdown - check perms before shutting down @sock conn
1022 */
apparmor_socket_shutdown(struct socket * sock,int how)1023 static int apparmor_socket_shutdown(struct socket *sock, int how)
1024 {
1025 return aa_sock_perm(OP_SHUTDOWN, AA_MAY_SHUTDOWN, sock);
1026 }
1027
1028 /**
1029 * apparmor_socket_sock_recv_skb - check perms before associating skb to sk
1030 *
1031 * Note: can not sleep may be called with locks held
1032 *
1033 * dont want protocol specific in __skb_recv_datagram()
1034 * to deny an incoming connection socket_sock_rcv_skb()
1035 */
apparmor_socket_sock_rcv_skb(struct sock * sk,struct sk_buff * skb)1036 static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
1037 {
1038 return 0;
1039 }
1040
1041
sk_peer_label(struct sock * sk)1042 static struct aa_label *sk_peer_label(struct sock *sk)
1043 {
1044 struct aa_sk_ctx *ctx = SK_CTX(sk);
1045
1046 if (ctx->peer)
1047 return ctx->peer;
1048
1049 return ERR_PTR(-ENOPROTOOPT);
1050 }
1051
1052 /**
1053 * apparmor_socket_getpeersec_stream - get security context of peer
1054 *
1055 * Note: for tcp only valid if using ipsec or cipso on lan
1056 */
apparmor_socket_getpeersec_stream(struct socket * sock,char __user * optval,int __user * optlen,unsigned int len)1057 static int apparmor_socket_getpeersec_stream(struct socket *sock,
1058 char __user *optval,
1059 int __user *optlen,
1060 unsigned int len)
1061 {
1062 char *name;
1063 int slen, error = 0;
1064 struct aa_label *label;
1065 struct aa_label *peer;
1066
1067 label = begin_current_label_crit_section();
1068 peer = sk_peer_label(sock->sk);
1069 if (IS_ERR(peer)) {
1070 error = PTR_ERR(peer);
1071 goto done;
1072 }
1073 slen = aa_label_asxprint(&name, labels_ns(label), peer,
1074 FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
1075 FLAG_HIDDEN_UNCONFINED, GFP_KERNEL);
1076 /* don't include terminating \0 in slen, it breaks some apps */
1077 if (slen < 0) {
1078 error = -ENOMEM;
1079 } else {
1080 if (slen > len) {
1081 error = -ERANGE;
1082 } else if (copy_to_user(optval, name, slen)) {
1083 error = -EFAULT;
1084 goto out;
1085 }
1086 if (put_user(slen, optlen))
1087 error = -EFAULT;
1088 out:
1089 kfree(name);
1090
1091 }
1092
1093 done:
1094 end_current_label_crit_section(label);
1095
1096 return error;
1097 }
1098
1099 /**
1100 * apparmor_socket_getpeersec_dgram - get security label of packet
1101 * @sock: the peer socket
1102 * @skb: packet data
1103 * @secid: pointer to where to put the secid of the packet
1104 *
1105 * Sets the netlabel socket state on sk from parent
1106 */
apparmor_socket_getpeersec_dgram(struct socket * sock,struct sk_buff * skb,u32 * secid)1107 static int apparmor_socket_getpeersec_dgram(struct socket *sock,
1108 struct sk_buff *skb, u32 *secid)
1109
1110 {
1111 /* TODO: requires secid support */
1112 return -ENOPROTOOPT;
1113 }
1114
1115 /**
1116 * apparmor_sock_graft - Initialize newly created socket
1117 * @sk: child sock
1118 * @parent: parent socket
1119 *
1120 * Note: could set off of SOCK_CTX(parent) but need to track inode and we can
1121 * just set sk security information off of current creating process label
1122 * Labeling of sk for accept case - probably should be sock based
1123 * instead of task, because of the case where an implicitly labeled
1124 * socket is shared by different tasks.
1125 */
apparmor_sock_graft(struct sock * sk,struct socket * parent)1126 static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
1127 {
1128 struct aa_sk_ctx *ctx = SK_CTX(sk);
1129
1130 if (!ctx->label)
1131 ctx->label = aa_get_current_label();
1132 }
1133
1134 static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
1135 LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
1136 LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
1137 LSM_HOOK_INIT(capget, apparmor_capget),
1138 LSM_HOOK_INIT(capable, apparmor_capable),
1139
1140 LSM_HOOK_INIT(sb_mount, apparmor_sb_mount),
1141 LSM_HOOK_INIT(sb_umount, apparmor_sb_umount),
1142 LSM_HOOK_INIT(sb_pivotroot, apparmor_sb_pivotroot),
1143
1144 LSM_HOOK_INIT(path_link, apparmor_path_link),
1145 LSM_HOOK_INIT(path_unlink, apparmor_path_unlink),
1146 LSM_HOOK_INIT(path_symlink, apparmor_path_symlink),
1147 LSM_HOOK_INIT(path_mkdir, apparmor_path_mkdir),
1148 LSM_HOOK_INIT(path_rmdir, apparmor_path_rmdir),
1149 LSM_HOOK_INIT(path_mknod, apparmor_path_mknod),
1150 LSM_HOOK_INIT(path_rename, apparmor_path_rename),
1151 LSM_HOOK_INIT(path_chmod, apparmor_path_chmod),
1152 LSM_HOOK_INIT(path_chown, apparmor_path_chown),
1153 LSM_HOOK_INIT(path_truncate, apparmor_path_truncate),
1154 LSM_HOOK_INIT(inode_getattr, apparmor_inode_getattr),
1155
1156 LSM_HOOK_INIT(file_open, apparmor_file_open),
1157 LSM_HOOK_INIT(file_receive, apparmor_file_receive),
1158 LSM_HOOK_INIT(file_permission, apparmor_file_permission),
1159 LSM_HOOK_INIT(file_alloc_security, apparmor_file_alloc_security),
1160 LSM_HOOK_INIT(file_free_security, apparmor_file_free_security),
1161 LSM_HOOK_INIT(mmap_file, apparmor_mmap_file),
1162 LSM_HOOK_INIT(file_mprotect, apparmor_file_mprotect),
1163 LSM_HOOK_INIT(file_lock, apparmor_file_lock),
1164
1165 LSM_HOOK_INIT(getprocattr, apparmor_getprocattr),
1166 LSM_HOOK_INIT(setprocattr, apparmor_setprocattr),
1167
1168 LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security),
1169 LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security),
1170 LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security),
1171
1172 LSM_HOOK_INIT(socket_create, apparmor_socket_create),
1173 LSM_HOOK_INIT(socket_post_create, apparmor_socket_post_create),
1174 LSM_HOOK_INIT(socket_bind, apparmor_socket_bind),
1175 LSM_HOOK_INIT(socket_connect, apparmor_socket_connect),
1176 LSM_HOOK_INIT(socket_listen, apparmor_socket_listen),
1177 LSM_HOOK_INIT(socket_accept, apparmor_socket_accept),
1178 LSM_HOOK_INIT(socket_sendmsg, apparmor_socket_sendmsg),
1179 LSM_HOOK_INIT(socket_recvmsg, apparmor_socket_recvmsg),
1180 LSM_HOOK_INIT(socket_getsockname, apparmor_socket_getsockname),
1181 LSM_HOOK_INIT(socket_getpeername, apparmor_socket_getpeername),
1182 LSM_HOOK_INIT(socket_getsockopt, apparmor_socket_getsockopt),
1183 LSM_HOOK_INIT(socket_setsockopt, apparmor_socket_setsockopt),
1184 LSM_HOOK_INIT(socket_shutdown, apparmor_socket_shutdown),
1185 LSM_HOOK_INIT(socket_sock_rcv_skb, apparmor_socket_sock_rcv_skb),
1186 LSM_HOOK_INIT(socket_getpeersec_stream,
1187 apparmor_socket_getpeersec_stream),
1188 LSM_HOOK_INIT(socket_getpeersec_dgram,
1189 apparmor_socket_getpeersec_dgram),
1190 LSM_HOOK_INIT(sock_graft, apparmor_sock_graft),
1191
1192 LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank),
1193 LSM_HOOK_INIT(cred_free, apparmor_cred_free),
1194 LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare),
1195 LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer),
1196
1197 LSM_HOOK_INIT(bprm_set_creds, apparmor_bprm_set_creds),
1198 LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds),
1199 LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds),
1200
1201 LSM_HOOK_INIT(task_free, apparmor_task_free),
1202 LSM_HOOK_INIT(task_alloc, apparmor_task_alloc),
1203 LSM_HOOK_INIT(task_getsecid, apparmor_task_getsecid),
1204 LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit),
1205 LSM_HOOK_INIT(task_kill, apparmor_task_kill),
1206
1207 #ifdef CONFIG_AUDIT
1208 LSM_HOOK_INIT(audit_rule_init, aa_audit_rule_init),
1209 LSM_HOOK_INIT(audit_rule_known, aa_audit_rule_known),
1210 LSM_HOOK_INIT(audit_rule_match, aa_audit_rule_match),
1211 LSM_HOOK_INIT(audit_rule_free, aa_audit_rule_free),
1212 #endif
1213
1214 LSM_HOOK_INIT(secid_to_secctx, apparmor_secid_to_secctx),
1215 LSM_HOOK_INIT(secctx_to_secid, apparmor_secctx_to_secid),
1216 LSM_HOOK_INIT(release_secctx, apparmor_release_secctx),
1217 };
1218
1219 /*
1220 * AppArmor sysfs module parameters
1221 */
1222
1223 static int param_set_aabool(const char *val, const struct kernel_param *kp);
1224 static int param_get_aabool(char *buffer, const struct kernel_param *kp);
1225 #define param_check_aabool param_check_bool
1226 static const struct kernel_param_ops param_ops_aabool = {
1227 .flags = KERNEL_PARAM_OPS_FL_NOARG,
1228 .set = param_set_aabool,
1229 .get = param_get_aabool
1230 };
1231
1232 static int param_set_aauint(const char *val, const struct kernel_param *kp);
1233 static int param_get_aauint(char *buffer, const struct kernel_param *kp);
1234 #define param_check_aauint param_check_uint
1235 static const struct kernel_param_ops param_ops_aauint = {
1236 .set = param_set_aauint,
1237 .get = param_get_aauint
1238 };
1239
1240 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
1241 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
1242 #define param_check_aalockpolicy param_check_bool
1243 static const struct kernel_param_ops param_ops_aalockpolicy = {
1244 .flags = KERNEL_PARAM_OPS_FL_NOARG,
1245 .set = param_set_aalockpolicy,
1246 .get = param_get_aalockpolicy
1247 };
1248
1249 static int param_set_audit(const char *val, const struct kernel_param *kp);
1250 static int param_get_audit(char *buffer, const struct kernel_param *kp);
1251
1252 static int param_set_mode(const char *val, const struct kernel_param *kp);
1253 static int param_get_mode(char *buffer, const struct kernel_param *kp);
1254
1255 /* Flag values, also controllable via /sys/module/apparmor/parameters
1256 * We define special types as we want to do additional mediation.
1257 */
1258
1259 /* AppArmor global enforcement switch - complain, enforce, kill */
1260 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
1261 module_param_call(mode, param_set_mode, param_get_mode,
1262 &aa_g_profile_mode, S_IRUSR | S_IWUSR);
1263
1264 /* whether policy verification hashing is enabled */
1265 bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT);
1266 #ifdef CONFIG_SECURITY_APPARMOR_HASH
1267 module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR);
1268 #endif
1269
1270 /* Debug mode */
1271 bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_APPARMOR_DEBUG_MESSAGES);
1272 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
1273
1274 /* Audit mode */
1275 enum audit_mode aa_g_audit;
1276 module_param_call(audit, param_set_audit, param_get_audit,
1277 &aa_g_audit, S_IRUSR | S_IWUSR);
1278
1279 /* Determines if audit header is included in audited messages. This
1280 * provides more context if the audit daemon is not running
1281 */
1282 bool aa_g_audit_header = true;
1283 module_param_named(audit_header, aa_g_audit_header, aabool,
1284 S_IRUSR | S_IWUSR);
1285
1286 /* lock out loading/removal of policy
1287 * TODO: add in at boot loading of policy, which is the only way to
1288 * load policy, if lock_policy is set
1289 */
1290 bool aa_g_lock_policy;
1291 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
1292 S_IRUSR | S_IWUSR);
1293
1294 /* Syscall logging mode */
1295 bool aa_g_logsyscall;
1296 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
1297
1298 /* Maximum pathname length before accesses will start getting rejected */
1299 unsigned int aa_g_path_max = 2 * PATH_MAX;
1300 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR);
1301
1302 /* Determines how paranoid loading of policy is and how much verification
1303 * on the loaded policy is done.
1304 * DEPRECATED: read only as strict checking of load is always done now
1305 * that none root users (user namespaces) can load policy.
1306 */
1307 bool aa_g_paranoid_load = true;
1308 module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO);
1309
1310 /* Boot time disable flag */
1311 static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
1312 module_param_named(enabled, apparmor_enabled, bool, S_IRUGO);
1313
apparmor_enabled_setup(char * str)1314 static int __init apparmor_enabled_setup(char *str)
1315 {
1316 unsigned long enabled;
1317 int error = kstrtoul(str, 0, &enabled);
1318 if (!error)
1319 apparmor_enabled = enabled ? 1 : 0;
1320 return 1;
1321 }
1322
1323 __setup("apparmor=", apparmor_enabled_setup);
1324
1325 /* set global flag turning off the ability to load policy */
param_set_aalockpolicy(const char * val,const struct kernel_param * kp)1326 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
1327 {
1328 if (!apparmor_enabled)
1329 return -EINVAL;
1330 if (apparmor_initialized && !policy_admin_capable(NULL))
1331 return -EPERM;
1332 return param_set_bool(val, kp);
1333 }
1334
param_get_aalockpolicy(char * buffer,const struct kernel_param * kp)1335 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
1336 {
1337 if (!apparmor_enabled)
1338 return -EINVAL;
1339 if (apparmor_initialized && !policy_view_capable(NULL))
1340 return -EPERM;
1341 return param_get_bool(buffer, kp);
1342 }
1343
param_set_aabool(const char * val,const struct kernel_param * kp)1344 static int param_set_aabool(const char *val, const struct kernel_param *kp)
1345 {
1346 if (!apparmor_enabled)
1347 return -EINVAL;
1348 if (apparmor_initialized && !policy_admin_capable(NULL))
1349 return -EPERM;
1350 return param_set_bool(val, kp);
1351 }
1352
param_get_aabool(char * buffer,const struct kernel_param * kp)1353 static int param_get_aabool(char *buffer, const struct kernel_param *kp)
1354 {
1355 if (!apparmor_enabled)
1356 return -EINVAL;
1357 if (apparmor_initialized && !policy_view_capable(NULL))
1358 return -EPERM;
1359 return param_get_bool(buffer, kp);
1360 }
1361
param_set_aauint(const char * val,const struct kernel_param * kp)1362 static int param_set_aauint(const char *val, const struct kernel_param *kp)
1363 {
1364 int error;
1365
1366 if (!apparmor_enabled)
1367 return -EINVAL;
1368 /* file is ro but enforce 2nd line check */
1369 if (apparmor_initialized)
1370 return -EPERM;
1371
1372 error = param_set_uint(val, kp);
1373 pr_info("AppArmor: buffer size set to %d bytes\n", aa_g_path_max);
1374
1375 return error;
1376 }
1377
param_get_aauint(char * buffer,const struct kernel_param * kp)1378 static int param_get_aauint(char *buffer, const struct kernel_param *kp)
1379 {
1380 if (!apparmor_enabled)
1381 return -EINVAL;
1382 if (apparmor_initialized && !policy_view_capable(NULL))
1383 return -EPERM;
1384 return param_get_uint(buffer, kp);
1385 }
1386
param_get_audit(char * buffer,const struct kernel_param * kp)1387 static int param_get_audit(char *buffer, const struct kernel_param *kp)
1388 {
1389 if (!apparmor_enabled)
1390 return -EINVAL;
1391 if (apparmor_initialized && !policy_view_capable(NULL))
1392 return -EPERM;
1393 return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
1394 }
1395
param_set_audit(const char * val,const struct kernel_param * kp)1396 static int param_set_audit(const char *val, const struct kernel_param *kp)
1397 {
1398 int i;
1399
1400 if (!apparmor_enabled)
1401 return -EINVAL;
1402 if (!val)
1403 return -EINVAL;
1404 if (apparmor_initialized && !policy_admin_capable(NULL))
1405 return -EPERM;
1406
1407 i = match_string(audit_mode_names, AUDIT_MAX_INDEX, val);
1408 if (i < 0)
1409 return -EINVAL;
1410
1411 aa_g_audit = i;
1412 return 0;
1413 }
1414
param_get_mode(char * buffer,const struct kernel_param * kp)1415 static int param_get_mode(char *buffer, const struct kernel_param *kp)
1416 {
1417 if (!apparmor_enabled)
1418 return -EINVAL;
1419 if (apparmor_initialized && !policy_view_capable(NULL))
1420 return -EPERM;
1421
1422 return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]);
1423 }
1424
param_set_mode(const char * val,const struct kernel_param * kp)1425 static int param_set_mode(const char *val, const struct kernel_param *kp)
1426 {
1427 int i;
1428
1429 if (!apparmor_enabled)
1430 return -EINVAL;
1431 if (!val)
1432 return -EINVAL;
1433 if (apparmor_initialized && !policy_admin_capable(NULL))
1434 return -EPERM;
1435
1436 i = match_string(aa_profile_mode_names, APPARMOR_MODE_NAMES_MAX_INDEX,
1437 val);
1438 if (i < 0)
1439 return -EINVAL;
1440
1441 aa_g_profile_mode = i;
1442 return 0;
1443 }
1444
1445 /*
1446 * AppArmor init functions
1447 */
1448
1449 /**
1450 * set_init_ctx - set a task context and profile on the first task.
1451 *
1452 * TODO: allow setting an alternate profile than unconfined
1453 */
set_init_ctx(void)1454 static int __init set_init_ctx(void)
1455 {
1456 struct cred *cred = (struct cred *)current->real_cred;
1457 struct aa_task_ctx *ctx;
1458
1459 ctx = aa_alloc_task_ctx(GFP_KERNEL);
1460 if (!ctx)
1461 return -ENOMEM;
1462
1463 cred_label(cred) = aa_get_label(ns_unconfined(root_ns));
1464 task_ctx(current) = ctx;
1465
1466 return 0;
1467 }
1468
destroy_buffers(void)1469 static void destroy_buffers(void)
1470 {
1471 u32 i, j;
1472
1473 for_each_possible_cpu(i) {
1474 for_each_cpu_buffer(j) {
1475 kfree(per_cpu(aa_buffers, i).buf[j]);
1476 per_cpu(aa_buffers, i).buf[j] = NULL;
1477 }
1478 }
1479 }
1480
alloc_buffers(void)1481 static int __init alloc_buffers(void)
1482 {
1483 u32 i, j;
1484
1485 for_each_possible_cpu(i) {
1486 for_each_cpu_buffer(j) {
1487 char *buffer;
1488
1489 if (cpu_to_node(i) > num_online_nodes())
1490 /* fallback to kmalloc for offline nodes */
1491 buffer = kmalloc(aa_g_path_max, GFP_KERNEL);
1492 else
1493 buffer = kmalloc_node(aa_g_path_max, GFP_KERNEL,
1494 cpu_to_node(i));
1495 if (!buffer) {
1496 destroy_buffers();
1497 return -ENOMEM;
1498 }
1499 per_cpu(aa_buffers, i).buf[j] = buffer;
1500 }
1501 }
1502
1503 return 0;
1504 }
1505
1506 #ifdef CONFIG_SYSCTL
apparmor_dointvec(struct ctl_table * table,int write,void __user * buffer,size_t * lenp,loff_t * ppos)1507 static int apparmor_dointvec(struct ctl_table *table, int write,
1508 void __user *buffer, size_t *lenp, loff_t *ppos)
1509 {
1510 if (!policy_admin_capable(NULL))
1511 return -EPERM;
1512 if (!apparmor_enabled)
1513 return -EINVAL;
1514
1515 return proc_dointvec(table, write, buffer, lenp, ppos);
1516 }
1517
1518 static struct ctl_path apparmor_sysctl_path[] = {
1519 { .procname = "kernel", },
1520 { }
1521 };
1522
1523 static struct ctl_table apparmor_sysctl_table[] = {
1524 {
1525 .procname = "unprivileged_userns_apparmor_policy",
1526 .data = &unprivileged_userns_apparmor_policy,
1527 .maxlen = sizeof(int),
1528 .mode = 0600,
1529 .proc_handler = apparmor_dointvec,
1530 },
1531 { }
1532 };
1533
apparmor_init_sysctl(void)1534 static int __init apparmor_init_sysctl(void)
1535 {
1536 return register_sysctl_paths(apparmor_sysctl_path,
1537 apparmor_sysctl_table) ? 0 : -ENOMEM;
1538 }
1539 #else
apparmor_init_sysctl(void)1540 static inline int apparmor_init_sysctl(void)
1541 {
1542 return 0;
1543 }
1544 #endif /* CONFIG_SYSCTL */
1545
apparmor_init(void)1546 static int __init apparmor_init(void)
1547 {
1548 int error;
1549
1550 if (!apparmor_enabled || !security_module_enable("apparmor")) {
1551 aa_info_message("AppArmor disabled by boot time parameter");
1552 apparmor_enabled = false;
1553 return 0;
1554 }
1555
1556 aa_secids_init();
1557
1558 error = aa_setup_dfa_engine();
1559 if (error) {
1560 AA_ERROR("Unable to setup dfa engine\n");
1561 goto alloc_out;
1562 }
1563
1564 error = aa_alloc_root_ns();
1565 if (error) {
1566 AA_ERROR("Unable to allocate default profile namespace\n");
1567 goto alloc_out;
1568 }
1569
1570 error = apparmor_init_sysctl();
1571 if (error) {
1572 AA_ERROR("Unable to register sysctls\n");
1573 goto alloc_out;
1574
1575 }
1576
1577 error = alloc_buffers();
1578 if (error) {
1579 AA_ERROR("Unable to allocate work buffers\n");
1580 goto buffers_out;
1581 }
1582
1583 error = set_init_ctx();
1584 if (error) {
1585 AA_ERROR("Failed to set context on init task\n");
1586 aa_free_root_ns();
1587 goto buffers_out;
1588 }
1589 security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
1590 "apparmor");
1591
1592 /* Report that AppArmor successfully initialized */
1593 apparmor_initialized = 1;
1594 if (aa_g_profile_mode == APPARMOR_COMPLAIN)
1595 aa_info_message("AppArmor initialized: complain mode enabled");
1596 else if (aa_g_profile_mode == APPARMOR_KILL)
1597 aa_info_message("AppArmor initialized: kill mode enabled");
1598 else
1599 aa_info_message("AppArmor initialized");
1600
1601 return error;
1602
1603 buffers_out:
1604 destroy_buffers();
1605
1606 alloc_out:
1607 aa_destroy_aafs();
1608 aa_teardown_dfa_engine();
1609
1610 apparmor_enabled = false;
1611 return error;
1612 }
1613
1614 security_initcall(apparmor_init);
1615