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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 <linux/kmemleak.h> | |
27 | #include <net/sock.h> | |
28 | ||
29 | #include "include/apparmor.h" | |
30 | #include "include/apparmorfs.h" | |
31 | #include "include/audit.h" | |
32 | #include "include/capability.h" | |
33 | #include "include/context.h" | |
34 | #include "include/file.h" | |
35 | #include "include/ipc.h" | |
36 | #include "include/path.h" | |
37 | #include "include/policy.h" | |
38 | #include "include/policy_ns.h" | |
39 | #include "include/procattr.h" | |
40 | ||
41 | /* Flag indicating whether initialization completed */ | |
42 | int apparmor_initialized __initdata; | |
43 | ||
44 | DEFINE_PER_CPU(struct aa_buffers, aa_buffers); | |
45 | ||
46 | ||
47 | /* | |
48 | * LSM hook functions | |
49 | */ | |
50 | ||
51 | /* | |
52 | * free the associated aa_task_ctx and put its profiles | |
53 | */ | |
54 | static void apparmor_cred_free(struct cred *cred) | |
55 | { | |
56 | aa_free_task_context(cred_ctx(cred)); | |
57 | cred_ctx(cred) = NULL; | |
58 | } | |
59 | ||
60 | /* | |
61 | * allocate the apparmor part of blank credentials | |
62 | */ | |
63 | static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp) | |
64 | { | |
65 | /* freed by apparmor_cred_free */ | |
66 | struct aa_task_ctx *ctx = aa_alloc_task_context(gfp); | |
67 | ||
68 | if (!ctx) | |
69 | return -ENOMEM; | |
70 | ||
71 | cred_ctx(cred) = ctx; | |
72 | return 0; | |
73 | } | |
74 | ||
75 | /* | |
76 | * prepare new aa_task_ctx for modification by prepare_cred block | |
77 | */ | |
78 | static int apparmor_cred_prepare(struct cred *new, const struct cred *old, | |
79 | gfp_t gfp) | |
80 | { | |
81 | /* freed by apparmor_cred_free */ | |
82 | struct aa_task_ctx *ctx = aa_alloc_task_context(gfp); | |
83 | ||
84 | if (!ctx) | |
85 | return -ENOMEM; | |
86 | ||
87 | aa_dup_task_context(ctx, cred_ctx(old)); | |
88 | cred_ctx(new) = ctx; | |
89 | return 0; | |
90 | } | |
91 | ||
92 | /* | |
93 | * transfer the apparmor data to a blank set of creds | |
94 | */ | |
95 | static void apparmor_cred_transfer(struct cred *new, const struct cred *old) | |
96 | { | |
97 | const struct aa_task_ctx *old_ctx = cred_ctx(old); | |
98 | struct aa_task_ctx *new_ctx = cred_ctx(new); | |
99 | ||
100 | aa_dup_task_context(new_ctx, old_ctx); | |
101 | } | |
102 | ||
103 | static int apparmor_ptrace_access_check(struct task_struct *child, | |
104 | unsigned int mode) | |
105 | { | |
106 | return aa_ptrace(current, child, mode); | |
107 | } | |
108 | ||
109 | static int apparmor_ptrace_traceme(struct task_struct *parent) | |
110 | { | |
111 | return aa_ptrace(parent, current, PTRACE_MODE_ATTACH); | |
112 | } | |
113 | ||
114 | /* Derived from security/commoncap.c:cap_capget */ | |
115 | static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective, | |
116 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | |
117 | { | |
118 | struct aa_profile *profile; | |
119 | const struct cred *cred; | |
120 | ||
121 | rcu_read_lock(); | |
122 | cred = __task_cred(target); | |
123 | profile = aa_cred_profile(cred); | |
124 | ||
125 | /* | |
126 | * cap_capget is stacked ahead of this and will | |
127 | * initialize effective and permitted. | |
128 | */ | |
129 | if (!unconfined(profile) && !COMPLAIN_MODE(profile)) { | |
130 | *effective = cap_intersect(*effective, profile->caps.allow); | |
131 | *permitted = cap_intersect(*permitted, profile->caps.allow); | |
132 | } | |
133 | rcu_read_unlock(); | |
134 | ||
135 | return 0; | |
136 | } | |
137 | ||
138 | static int apparmor_capable(const struct cred *cred, struct user_namespace *ns, | |
139 | int cap, int audit) | |
140 | { | |
141 | struct aa_profile *profile; | |
142 | int error = 0; | |
143 | ||
144 | profile = aa_cred_profile(cred); | |
145 | if (!unconfined(profile)) | |
146 | error = aa_capable(profile, cap, audit); | |
147 | return error; | |
148 | } | |
149 | ||
150 | /** | |
151 | * common_perm - basic common permission check wrapper fn for paths | |
152 | * @op: operation being checked | |
153 | * @path: path to check permission of (NOT NULL) | |
154 | * @mask: requested permissions mask | |
155 | * @cond: conditional info for the permission request (NOT NULL) | |
156 | * | |
157 | * Returns: %0 else error code if error or permission denied | |
158 | */ | |
159 | static int common_perm(const char *op, const struct path *path, u32 mask, | |
160 | struct path_cond *cond) | |
161 | { | |
162 | struct aa_profile *profile; | |
163 | int error = 0; | |
164 | ||
165 | profile = __aa_current_profile(); | |
166 | if (!unconfined(profile)) | |
167 | error = aa_path_perm(op, profile, path, 0, mask, cond); | |
168 | ||
169 | return error; | |
170 | } | |
171 | ||
172 | /** | |
173 | * common_perm_cond - common permission wrapper around inode cond | |
174 | * @op: operation being checked | |
175 | * @path: location to check (NOT NULL) | |
176 | * @mask: requested permissions mask | |
177 | * | |
178 | * Returns: %0 else error code if error or permission denied | |
179 | */ | |
180 | static int common_perm_cond(const char *op, const struct path *path, u32 mask) | |
181 | { | |
182 | struct path_cond cond = { d_backing_inode(path->dentry)->i_uid, | |
183 | d_backing_inode(path->dentry)->i_mode | |
184 | }; | |
185 | ||
186 | if (!path_mediated_fs(path->dentry)) | |
187 | return 0; | |
188 | ||
189 | return common_perm(op, path, mask, &cond); | |
190 | } | |
191 | ||
192 | /** | |
193 | * common_perm_dir_dentry - common permission wrapper when path is dir, dentry | |
194 | * @op: operation being checked | |
195 | * @dir: directory of the dentry (NOT NULL) | |
196 | * @dentry: dentry to check (NOT NULL) | |
197 | * @mask: requested permissions mask | |
198 | * @cond: conditional info for the permission request (NOT NULL) | |
199 | * | |
200 | * Returns: %0 else error code if error or permission denied | |
201 | */ | |
202 | static int common_perm_dir_dentry(const char *op, const struct path *dir, | |
203 | struct dentry *dentry, u32 mask, | |
204 | struct path_cond *cond) | |
205 | { | |
206 | struct path path = { .mnt = dir->mnt, .dentry = dentry }; | |
207 | ||
208 | return common_perm(op, &path, mask, cond); | |
209 | } | |
210 | ||
211 | /** | |
212 | * common_perm_rm - common permission wrapper for operations doing rm | |
213 | * @op: operation being checked | |
214 | * @dir: directory that the dentry is in (NOT NULL) | |
215 | * @dentry: dentry being rm'd (NOT NULL) | |
216 | * @mask: requested permission mask | |
217 | * | |
218 | * Returns: %0 else error code if error or permission denied | |
219 | */ | |
220 | static int common_perm_rm(const char *op, const struct path *dir, | |
221 | struct dentry *dentry, u32 mask) | |
222 | { | |
223 | struct inode *inode = d_backing_inode(dentry); | |
224 | struct path_cond cond = { }; | |
225 | ||
226 | if (!inode || !path_mediated_fs(dentry)) | |
227 | return 0; | |
228 | ||
229 | cond.uid = inode->i_uid; | |
230 | cond.mode = inode->i_mode; | |
231 | ||
232 | return common_perm_dir_dentry(op, dir, dentry, mask, &cond); | |
233 | } | |
234 | ||
235 | /** | |
236 | * common_perm_create - common permission wrapper for operations doing create | |
237 | * @op: operation being checked | |
238 | * @dir: directory that dentry will be created in (NOT NULL) | |
239 | * @dentry: dentry to create (NOT NULL) | |
240 | * @mask: request permission mask | |
241 | * @mode: created file mode | |
242 | * | |
243 | * Returns: %0 else error code if error or permission denied | |
244 | */ | |
245 | static int common_perm_create(const char *op, const struct path *dir, | |
246 | struct dentry *dentry, u32 mask, umode_t mode) | |
247 | { | |
248 | struct path_cond cond = { current_fsuid(), mode }; | |
249 | ||
250 | if (!path_mediated_fs(dir->dentry)) | |
251 | return 0; | |
252 | ||
253 | return common_perm_dir_dentry(op, dir, dentry, mask, &cond); | |
254 | } | |
255 | ||
256 | static int apparmor_path_unlink(const struct path *dir, struct dentry *dentry) | |
257 | { | |
258 | return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE); | |
259 | } | |
260 | ||
261 | static int apparmor_path_mkdir(const struct path *dir, struct dentry *dentry, | |
262 | umode_t mode) | |
263 | { | |
264 | return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE, | |
265 | S_IFDIR); | |
266 | } | |
267 | ||
268 | static int apparmor_path_rmdir(const struct path *dir, struct dentry *dentry) | |
269 | { | |
270 | return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE); | |
271 | } | |
272 | ||
273 | static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry, | |
274 | umode_t mode, unsigned int dev) | |
275 | { | |
276 | return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode); | |
277 | } | |
278 | ||
279 | static int apparmor_path_truncate(const struct path *path) | |
280 | { | |
281 | return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE); | |
282 | } | |
283 | ||
284 | static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry, | |
285 | const char *old_name) | |
286 | { | |
287 | return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE, | |
288 | S_IFLNK); | |
289 | } | |
290 | ||
291 | static int apparmor_path_link(struct dentry *old_dentry, const struct path *new_dir, | |
292 | struct dentry *new_dentry) | |
293 | { | |
294 | struct aa_profile *profile; | |
295 | int error = 0; | |
296 | ||
297 | if (!path_mediated_fs(old_dentry)) | |
298 | return 0; | |
299 | ||
300 | profile = aa_current_profile(); | |
301 | if (!unconfined(profile)) | |
302 | error = aa_path_link(profile, old_dentry, new_dir, new_dentry); | |
303 | return error; | |
304 | } | |
305 | ||
306 | static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_dentry, | |
307 | const struct path *new_dir, struct dentry *new_dentry) | |
308 | { | |
309 | struct aa_profile *profile; | |
310 | int error = 0; | |
311 | ||
312 | if (!path_mediated_fs(old_dentry)) | |
313 | return 0; | |
314 | ||
315 | profile = aa_current_profile(); | |
316 | if (!unconfined(profile)) { | |
317 | struct path old_path = { .mnt = old_dir->mnt, | |
318 | .dentry = old_dentry }; | |
319 | struct path new_path = { .mnt = new_dir->mnt, | |
320 | .dentry = new_dentry }; | |
321 | struct path_cond cond = { d_backing_inode(old_dentry)->i_uid, | |
322 | d_backing_inode(old_dentry)->i_mode | |
323 | }; | |
324 | ||
325 | error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0, | |
326 | MAY_READ | AA_MAY_META_READ | MAY_WRITE | | |
327 | AA_MAY_META_WRITE | AA_MAY_DELETE, | |
328 | &cond); | |
329 | if (!error) | |
330 | error = aa_path_perm(OP_RENAME_DEST, profile, &new_path, | |
331 | 0, MAY_WRITE | AA_MAY_META_WRITE | | |
332 | AA_MAY_CREATE, &cond); | |
333 | ||
334 | } | |
335 | return error; | |
336 | } | |
337 | ||
338 | static int apparmor_path_chmod(const struct path *path, umode_t mode) | |
339 | { | |
340 | return common_perm_cond(OP_CHMOD, path, AA_MAY_CHMOD); | |
341 | } | |
342 | ||
343 | static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid) | |
344 | { | |
345 | return common_perm_cond(OP_CHOWN, path, AA_MAY_CHOWN); | |
346 | } | |
347 | ||
348 | static int apparmor_inode_getattr(const struct path *path) | |
349 | { | |
350 | return common_perm_cond(OP_GETATTR, path, AA_MAY_META_READ); | |
351 | } | |
352 | ||
353 | static int apparmor_file_open(struct file *file, const struct cred *cred) | |
354 | { | |
355 | struct aa_file_ctx *fctx = file->f_security; | |
356 | struct aa_profile *profile; | |
357 | int error = 0; | |
358 | ||
359 | if (!path_mediated_fs(file->f_path.dentry)) | |
360 | return 0; | |
361 | ||
362 | /* If in exec, permission is handled by bprm hooks. | |
363 | * Cache permissions granted by the previous exec check, with | |
364 | * implicit read and executable mmap which are required to | |
365 | * actually execute the image. | |
366 | */ | |
367 | if (current->in_execve) { | |
368 | fctx->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP; | |
369 | return 0; | |
370 | } | |
371 | ||
372 | profile = aa_cred_profile(cred); | |
373 | if (!unconfined(profile)) { | |
374 | struct inode *inode = file_inode(file); | |
375 | struct path_cond cond = { inode->i_uid, inode->i_mode }; | |
376 | ||
377 | error = aa_path_perm(OP_OPEN, profile, &file->f_path, 0, | |
378 | aa_map_file_to_perms(file), &cond); | |
379 | /* todo cache full allowed permissions set and state */ | |
380 | fctx->allow = aa_map_file_to_perms(file); | |
381 | } | |
382 | ||
383 | return error; | |
384 | } | |
385 | ||
386 | static int apparmor_file_alloc_security(struct file *file) | |
387 | { | |
388 | /* freed by apparmor_file_free_security */ | |
389 | file->f_security = aa_alloc_file_context(GFP_KERNEL); | |
390 | if (!file->f_security) | |
391 | return -ENOMEM; | |
392 | return 0; | |
393 | ||
394 | } | |
395 | ||
396 | static void apparmor_file_free_security(struct file *file) | |
397 | { | |
398 | struct aa_file_ctx *ctx = file->f_security; | |
399 | ||
400 | aa_free_file_context(ctx); | |
401 | } | |
402 | ||
403 | static int common_file_perm(const char *op, struct file *file, u32 mask) | |
404 | { | |
405 | struct aa_file_ctx *fctx = file->f_security; | |
406 | struct aa_profile *profile, *fprofile = aa_cred_profile(file->f_cred); | |
407 | int error = 0; | |
408 | ||
409 | AA_BUG(!fprofile); | |
410 | ||
411 | if (!file->f_path.mnt || | |
412 | !path_mediated_fs(file->f_path.dentry)) | |
413 | return 0; | |
414 | ||
415 | profile = __aa_current_profile(); | |
416 | ||
417 | /* revalidate access, if task is unconfined, or the cached cred | |
418 | * doesn't match or if the request is for more permissions than | |
419 | * was granted. | |
420 | * | |
421 | * Note: the test for !unconfined(fprofile) is to handle file | |
422 | * delegation from unconfined tasks | |
423 | */ | |
424 | if (!unconfined(profile) && !unconfined(fprofile) && | |
425 | ((fprofile != profile) || (mask & ~fctx->allow))) | |
426 | error = aa_file_perm(op, profile, file, mask); | |
427 | ||
428 | return error; | |
429 | } | |
430 | ||
431 | static int apparmor_file_permission(struct file *file, int mask) | |
432 | { | |
433 | return common_file_perm(OP_FPERM, file, mask); | |
434 | } | |
435 | ||
436 | static int apparmor_file_lock(struct file *file, unsigned int cmd) | |
437 | { | |
438 | u32 mask = AA_MAY_LOCK; | |
439 | ||
440 | if (cmd == F_WRLCK) | |
441 | mask |= MAY_WRITE; | |
442 | ||
443 | return common_file_perm(OP_FLOCK, file, mask); | |
444 | } | |
445 | ||
446 | static int common_mmap(const char *op, struct file *file, unsigned long prot, | |
447 | unsigned long flags) | |
448 | { | |
449 | int mask = 0; | |
450 | ||
451 | if (!file || !file->f_security) | |
452 | return 0; | |
453 | ||
454 | if (prot & PROT_READ) | |
455 | mask |= MAY_READ; | |
456 | /* | |
457 | * Private mappings don't require write perms since they don't | |
458 | * write back to the files | |
459 | */ | |
460 | if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE)) | |
461 | mask |= MAY_WRITE; | |
462 | if (prot & PROT_EXEC) | |
463 | mask |= AA_EXEC_MMAP; | |
464 | ||
465 | return common_file_perm(op, file, mask); | |
466 | } | |
467 | ||
468 | static int apparmor_mmap_file(struct file *file, unsigned long reqprot, | |
469 | unsigned long prot, unsigned long flags) | |
470 | { | |
471 | return common_mmap(OP_FMMAP, file, prot, flags); | |
472 | } | |
473 | ||
474 | static int apparmor_file_mprotect(struct vm_area_struct *vma, | |
475 | unsigned long reqprot, unsigned long prot) | |
476 | { | |
477 | return common_mmap(OP_FMPROT, vma->vm_file, prot, | |
478 | !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0); | |
479 | } | |
480 | ||
481 | static int apparmor_getprocattr(struct task_struct *task, char *name, | |
482 | char **value) | |
483 | { | |
484 | int error = -ENOENT; | |
485 | /* released below */ | |
486 | const struct cred *cred = get_task_cred(task); | |
487 | struct aa_task_ctx *ctx = cred_ctx(cred); | |
488 | struct aa_profile *profile = NULL; | |
489 | ||
490 | if (strcmp(name, "current") == 0) | |
491 | profile = aa_get_newest_profile(ctx->profile); | |
492 | else if (strcmp(name, "prev") == 0 && ctx->previous) | |
493 | profile = aa_get_newest_profile(ctx->previous); | |
494 | else if (strcmp(name, "exec") == 0 && ctx->onexec) | |
495 | profile = aa_get_newest_profile(ctx->onexec); | |
496 | else | |
497 | error = -EINVAL; | |
498 | ||
499 | if (profile) | |
500 | error = aa_getprocattr(profile, value); | |
501 | ||
502 | aa_put_profile(profile); | |
503 | put_cred(cred); | |
504 | ||
505 | return error; | |
506 | } | |
507 | ||
508 | static int apparmor_setprocattr(const char *name, void *value, | |
509 | size_t size) | |
510 | { | |
511 | char *command, *largs = NULL, *args = value; | |
512 | size_t arg_size; | |
513 | int error; | |
514 | DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SETPROCATTR); | |
515 | ||
516 | if (size == 0) | |
517 | return -EINVAL; | |
518 | ||
519 | /* AppArmor requires that the buffer must be null terminated atm */ | |
520 | if (args[size - 1] != '\0') { | |
521 | /* null terminate */ | |
522 | largs = args = kmalloc(size + 1, GFP_KERNEL); | |
523 | if (!args) | |
524 | return -ENOMEM; | |
525 | memcpy(args, value, size); | |
526 | args[size] = '\0'; | |
527 | } | |
528 | ||
529 | error = -EINVAL; | |
530 | args = strim(args); | |
531 | command = strsep(&args, " "); | |
532 | if (!args) | |
533 | goto out; | |
534 | args = skip_spaces(args); | |
535 | if (!*args) | |
536 | goto out; | |
537 | ||
538 | arg_size = size - (args - (largs ? largs : (char *) value)); | |
539 | if (strcmp(name, "current") == 0) { | |
540 | if (strcmp(command, "changehat") == 0) { | |
541 | error = aa_setprocattr_changehat(args, arg_size, | |
542 | !AA_DO_TEST); | |
543 | } else if (strcmp(command, "permhat") == 0) { | |
544 | error = aa_setprocattr_changehat(args, arg_size, | |
545 | AA_DO_TEST); | |
546 | } else if (strcmp(command, "changeprofile") == 0) { | |
547 | error = aa_change_profile(args, !AA_ONEXEC, | |
548 | !AA_DO_TEST, false); | |
549 | } else if (strcmp(command, "permprofile") == 0) { | |
550 | error = aa_change_profile(args, !AA_ONEXEC, AA_DO_TEST, | |
551 | false); | |
552 | } else | |
553 | goto fail; | |
554 | } else if (strcmp(name, "exec") == 0) { | |
555 | if (strcmp(command, "exec") == 0) | |
556 | error = aa_change_profile(args, AA_ONEXEC, !AA_DO_TEST, | |
557 | false); | |
558 | else | |
559 | goto fail; | |
560 | } else | |
561 | /* only support the "current" and "exec" process attributes */ | |
562 | goto fail; | |
563 | ||
564 | if (!error) | |
565 | error = size; | |
566 | out: | |
567 | kfree(largs); | |
568 | return error; | |
569 | ||
570 | fail: | |
571 | aad(&sa)->profile = aa_current_profile(); | |
572 | aad(&sa)->info = name; | |
573 | aad(&sa)->error = error = -EINVAL; | |
574 | aa_audit_msg(AUDIT_APPARMOR_DENIED, &sa, NULL); | |
575 | goto out; | |
576 | } | |
577 | ||
578 | static int apparmor_task_setrlimit(struct task_struct *task, | |
579 | unsigned int resource, struct rlimit *new_rlim) | |
580 | { | |
581 | struct aa_profile *profile = __aa_current_profile(); | |
582 | int error = 0; | |
583 | ||
584 | if (!unconfined(profile)) | |
585 | error = aa_task_setrlimit(profile, task, resource, new_rlim); | |
586 | ||
587 | return error; | |
588 | } | |
589 | ||
590 | static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = { | |
591 | LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check), | |
592 | LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme), | |
593 | LSM_HOOK_INIT(capget, apparmor_capget), | |
594 | LSM_HOOK_INIT(capable, apparmor_capable), | |
595 | ||
596 | LSM_HOOK_INIT(path_link, apparmor_path_link), | |
597 | LSM_HOOK_INIT(path_unlink, apparmor_path_unlink), | |
598 | LSM_HOOK_INIT(path_symlink, apparmor_path_symlink), | |
599 | LSM_HOOK_INIT(path_mkdir, apparmor_path_mkdir), | |
600 | LSM_HOOK_INIT(path_rmdir, apparmor_path_rmdir), | |
601 | LSM_HOOK_INIT(path_mknod, apparmor_path_mknod), | |
602 | LSM_HOOK_INIT(path_rename, apparmor_path_rename), | |
603 | LSM_HOOK_INIT(path_chmod, apparmor_path_chmod), | |
604 | LSM_HOOK_INIT(path_chown, apparmor_path_chown), | |
605 | LSM_HOOK_INIT(path_truncate, apparmor_path_truncate), | |
606 | LSM_HOOK_INIT(inode_getattr, apparmor_inode_getattr), | |
607 | ||
608 | LSM_HOOK_INIT(file_open, apparmor_file_open), | |
609 | LSM_HOOK_INIT(file_permission, apparmor_file_permission), | |
610 | LSM_HOOK_INIT(file_alloc_security, apparmor_file_alloc_security), | |
611 | LSM_HOOK_INIT(file_free_security, apparmor_file_free_security), | |
612 | LSM_HOOK_INIT(mmap_file, apparmor_mmap_file), | |
613 | LSM_HOOK_INIT(file_mprotect, apparmor_file_mprotect), | |
614 | LSM_HOOK_INIT(file_lock, apparmor_file_lock), | |
615 | ||
616 | LSM_HOOK_INIT(getprocattr, apparmor_getprocattr), | |
617 | LSM_HOOK_INIT(setprocattr, apparmor_setprocattr), | |
618 | ||
619 | LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank), | |
620 | LSM_HOOK_INIT(cred_free, apparmor_cred_free), | |
621 | LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare), | |
622 | LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer), | |
623 | ||
624 | LSM_HOOK_INIT(bprm_set_creds, apparmor_bprm_set_creds), | |
625 | LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds), | |
626 | LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds), | |
627 | LSM_HOOK_INIT(bprm_secureexec, apparmor_bprm_secureexec), | |
628 | ||
629 | LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit), | |
630 | }; | |
631 | ||
632 | /* | |
633 | * AppArmor sysfs module parameters | |
634 | */ | |
635 | ||
636 | static int param_set_aabool(const char *val, const struct kernel_param *kp); | |
637 | static int param_get_aabool(char *buffer, const struct kernel_param *kp); | |
638 | #define param_check_aabool param_check_bool | |
639 | static const struct kernel_param_ops param_ops_aabool = { | |
640 | .flags = KERNEL_PARAM_OPS_FL_NOARG, | |
641 | .set = param_set_aabool, | |
642 | .get = param_get_aabool | |
643 | }; | |
644 | ||
645 | static int param_set_aauint(const char *val, const struct kernel_param *kp); | |
646 | static int param_get_aauint(char *buffer, const struct kernel_param *kp); | |
647 | #define param_check_aauint param_check_uint | |
648 | static const struct kernel_param_ops param_ops_aauint = { | |
649 | .set = param_set_aauint, | |
650 | .get = param_get_aauint | |
651 | }; | |
652 | ||
653 | static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp); | |
654 | static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp); | |
655 | #define param_check_aalockpolicy param_check_bool | |
656 | static const struct kernel_param_ops param_ops_aalockpolicy = { | |
657 | .flags = KERNEL_PARAM_OPS_FL_NOARG, | |
658 | .set = param_set_aalockpolicy, | |
659 | .get = param_get_aalockpolicy | |
660 | }; | |
661 | ||
662 | static int param_set_audit(const char *val, struct kernel_param *kp); | |
663 | static int param_get_audit(char *buffer, struct kernel_param *kp); | |
664 | ||
665 | static int param_set_mode(const char *val, struct kernel_param *kp); | |
666 | static int param_get_mode(char *buffer, struct kernel_param *kp); | |
667 | ||
668 | /* Flag values, also controllable via /sys/module/apparmor/parameters | |
669 | * We define special types as we want to do additional mediation. | |
670 | */ | |
671 | ||
672 | /* AppArmor global enforcement switch - complain, enforce, kill */ | |
673 | enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE; | |
674 | module_param_call(mode, param_set_mode, param_get_mode, | |
675 | &aa_g_profile_mode, S_IRUSR | S_IWUSR); | |
676 | ||
677 | /* whether policy verification hashing is enabled */ | |
678 | bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT); | |
679 | #ifdef CONFIG_SECURITY_APPARMOR_HASH | |
680 | module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR); | |
681 | #endif | |
682 | ||
683 | /* Debug mode */ | |
684 | bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_DEBUG_MESSAGES); | |
685 | module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR); | |
686 | ||
687 | /* Audit mode */ | |
688 | enum audit_mode aa_g_audit; | |
689 | module_param_call(audit, param_set_audit, param_get_audit, | |
690 | &aa_g_audit, S_IRUSR | S_IWUSR); | |
691 | ||
692 | /* Determines if audit header is included in audited messages. This | |
693 | * provides more context if the audit daemon is not running | |
694 | */ | |
695 | bool aa_g_audit_header = 1; | |
696 | module_param_named(audit_header, aa_g_audit_header, aabool, | |
697 | S_IRUSR | S_IWUSR); | |
698 | ||
699 | /* lock out loading/removal of policy | |
700 | * TODO: add in at boot loading of policy, which is the only way to | |
701 | * load policy, if lock_policy is set | |
702 | */ | |
703 | bool aa_g_lock_policy; | |
704 | module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy, | |
705 | S_IRUSR | S_IWUSR); | |
706 | ||
707 | /* Syscall logging mode */ | |
708 | bool aa_g_logsyscall; | |
709 | module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR); | |
710 | ||
711 | /* Maximum pathname length before accesses will start getting rejected */ | |
712 | unsigned int aa_g_path_max = 2 * PATH_MAX; | |
713 | module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR); | |
714 | ||
715 | /* Determines how paranoid loading of policy is and how much verification | |
716 | * on the loaded policy is done. | |
717 | * DEPRECATED: read only as strict checking of load is always done now | |
718 | * that none root users (user namespaces) can load policy. | |
719 | */ | |
720 | bool aa_g_paranoid_load = 1; | |
721 | module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO); | |
722 | ||
723 | /* Boot time disable flag */ | |
724 | static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE; | |
725 | module_param_named(enabled, apparmor_enabled, bool, S_IRUGO); | |
726 | ||
727 | static int __init apparmor_enabled_setup(char *str) | |
728 | { | |
729 | unsigned long enabled; | |
730 | int error = kstrtoul(str, 0, &enabled); | |
731 | if (!error) | |
732 | apparmor_enabled = enabled ? 1 : 0; | |
733 | return 1; | |
734 | } | |
735 | ||
736 | __setup("apparmor=", apparmor_enabled_setup); | |
737 | ||
738 | /* set global flag turning off the ability to load policy */ | |
739 | static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp) | |
740 | { | |
741 | if (!policy_admin_capable(NULL)) | |
742 | return -EPERM; | |
743 | return param_set_bool(val, kp); | |
744 | } | |
745 | ||
746 | static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp) | |
747 | { | |
748 | if (!policy_view_capable(NULL)) | |
749 | return -EPERM; | |
750 | if (!apparmor_enabled) | |
751 | return -EINVAL; | |
752 | return param_get_bool(buffer, kp); | |
753 | } | |
754 | ||
755 | static int param_set_aabool(const char *val, const struct kernel_param *kp) | |
756 | { | |
757 | if (!policy_admin_capable(NULL)) | |
758 | return -EPERM; | |
759 | if (!apparmor_enabled) | |
760 | return -EINVAL; | |
761 | return param_set_bool(val, kp); | |
762 | } | |
763 | ||
764 | static int param_get_aabool(char *buffer, const struct kernel_param *kp) | |
765 | { | |
766 | if (!policy_view_capable(NULL)) | |
767 | return -EPERM; | |
768 | if (!apparmor_enabled) | |
769 | return -EINVAL; | |
770 | return param_get_bool(buffer, kp); | |
771 | } | |
772 | ||
773 | static int param_set_aauint(const char *val, const struct kernel_param *kp) | |
774 | { | |
775 | if (!policy_admin_capable(NULL)) | |
776 | return -EPERM; | |
777 | if (!apparmor_enabled) | |
778 | return -EINVAL; | |
779 | return param_set_uint(val, kp); | |
780 | } | |
781 | ||
782 | static int param_get_aauint(char *buffer, const struct kernel_param *kp) | |
783 | { | |
784 | if (!policy_view_capable(NULL)) | |
785 | return -EPERM; | |
786 | if (!apparmor_enabled) | |
787 | return -EINVAL; | |
788 | return param_get_uint(buffer, kp); | |
789 | } | |
790 | ||
791 | static int param_get_audit(char *buffer, struct kernel_param *kp) | |
792 | { | |
793 | if (!policy_view_capable(NULL)) | |
794 | return -EPERM; | |
795 | ||
796 | if (!apparmor_enabled) | |
797 | return -EINVAL; | |
798 | ||
799 | return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]); | |
800 | } | |
801 | ||
802 | static int param_set_audit(const char *val, struct kernel_param *kp) | |
803 | { | |
804 | int i; | |
805 | if (!policy_admin_capable(NULL)) | |
806 | return -EPERM; | |
807 | ||
808 | if (!apparmor_enabled) | |
809 | return -EINVAL; | |
810 | ||
811 | if (!val) | |
812 | return -EINVAL; | |
813 | ||
814 | for (i = 0; i < AUDIT_MAX_INDEX; i++) { | |
815 | if (strcmp(val, audit_mode_names[i]) == 0) { | |
816 | aa_g_audit = i; | |
817 | return 0; | |
818 | } | |
819 | } | |
820 | ||
821 | return -EINVAL; | |
822 | } | |
823 | ||
824 | static int param_get_mode(char *buffer, struct kernel_param *kp) | |
825 | { | |
826 | if (!policy_view_capable(NULL)) | |
827 | return -EPERM; | |
828 | ||
829 | if (!apparmor_enabled) | |
830 | return -EINVAL; | |
831 | ||
832 | return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]); | |
833 | } | |
834 | ||
835 | static int param_set_mode(const char *val, struct kernel_param *kp) | |
836 | { | |
837 | int i; | |
838 | if (!policy_admin_capable(NULL)) | |
839 | return -EPERM; | |
840 | ||
841 | if (!apparmor_enabled) | |
842 | return -EINVAL; | |
843 | ||
844 | if (!val) | |
845 | return -EINVAL; | |
846 | ||
847 | for (i = 0; i < APPARMOR_MODE_NAMES_MAX_INDEX; i++) { | |
848 | if (strcmp(val, aa_profile_mode_names[i]) == 0) { | |
849 | aa_g_profile_mode = i; | |
850 | return 0; | |
851 | } | |
852 | } | |
853 | ||
854 | return -EINVAL; | |
855 | } | |
856 | ||
857 | /* | |
858 | * AppArmor init functions | |
859 | */ | |
860 | ||
861 | /** | |
862 | * set_init_ctx - set a task context and profile on the first task. | |
863 | * | |
864 | * TODO: allow setting an alternate profile than unconfined | |
865 | */ | |
866 | static int __init set_init_ctx(void) | |
867 | { | |
868 | struct cred *cred = (struct cred *)current->real_cred; | |
869 | struct aa_task_ctx *ctx; | |
870 | ||
871 | ctx = aa_alloc_task_context(GFP_KERNEL); | |
872 | if (!ctx) | |
873 | return -ENOMEM; | |
874 | ||
875 | ctx->profile = aa_get_profile(root_ns->unconfined); | |
876 | cred_ctx(cred) = ctx; | |
877 | ||
878 | return 0; | |
879 | } | |
880 | ||
881 | static void destroy_buffers(void) | |
882 | { | |
883 | u32 i, j; | |
884 | ||
885 | for_each_possible_cpu(i) { | |
886 | for_each_cpu_buffer(j) { | |
887 | kfree(per_cpu(aa_buffers, i).buf[j]); | |
888 | per_cpu(aa_buffers, i).buf[j] = NULL; | |
889 | } | |
890 | } | |
891 | } | |
892 | ||
893 | static int __init alloc_buffers(void) | |
894 | { | |
895 | u32 i, j; | |
896 | ||
897 | for_each_possible_cpu(i) { | |
898 | for_each_cpu_buffer(j) { | |
899 | char *buffer; | |
900 | ||
901 | if (cpu_to_node(i) > num_online_nodes()) | |
902 | /* fallback to kmalloc for offline nodes */ | |
903 | buffer = kmalloc(aa_g_path_max, GFP_KERNEL); | |
904 | else | |
905 | buffer = kmalloc_node(aa_g_path_max, GFP_KERNEL, | |
906 | cpu_to_node(i)); | |
907 | if (!buffer) { | |
908 | destroy_buffers(); | |
909 | return -ENOMEM; | |
910 | } | |
911 | per_cpu(aa_buffers, i).buf[j] = buffer; | |
912 | } | |
913 | } | |
914 | ||
915 | return 0; | |
916 | } | |
917 | ||
918 | #ifdef CONFIG_SYSCTL | |
919 | static int apparmor_dointvec(struct ctl_table *table, int write, | |
920 | void __user *buffer, size_t *lenp, loff_t *ppos) | |
921 | { | |
922 | if (!policy_admin_capable(NULL)) | |
923 | return -EPERM; | |
924 | if (!apparmor_enabled) | |
925 | return -EINVAL; | |
926 | ||
927 | return proc_dointvec(table, write, buffer, lenp, ppos); | |
928 | } | |
929 | ||
930 | static struct ctl_path apparmor_sysctl_path[] = { | |
931 | { .procname = "kernel", }, | |
932 | { } | |
933 | }; | |
934 | ||
935 | static struct ctl_table apparmor_sysctl_table[] = { | |
936 | { | |
937 | .procname = "unprivileged_userns_apparmor_policy", | |
938 | .data = &unprivileged_userns_apparmor_policy, | |
939 | .maxlen = sizeof(int), | |
940 | .mode = 0600, | |
941 | .proc_handler = apparmor_dointvec, | |
942 | }, | |
943 | { } | |
944 | }; | |
945 | ||
946 | static int __init apparmor_init_sysctl(void) | |
947 | { | |
948 | return register_sysctl_paths(apparmor_sysctl_path, | |
949 | apparmor_sysctl_table) ? 0 : -ENOMEM; | |
950 | } | |
951 | #else | |
952 | static inline int apparmor_init_sysctl(void) | |
953 | { | |
954 | return 0; | |
955 | } | |
956 | #endif /* CONFIG_SYSCTL */ | |
957 | ||
958 | static int __init apparmor_init(void) | |
959 | { | |
960 | int error; | |
961 | ||
962 | if (!apparmor_enabled || !security_module_enable("apparmor")) { | |
963 | aa_info_message("AppArmor disabled by boot time parameter"); | |
964 | apparmor_enabled = 0; | |
965 | return 0; | |
966 | } | |
967 | ||
968 | error = aa_setup_dfa_engine(); | |
969 | if (error) { | |
970 | AA_ERROR("Unable to setup dfa engine\n"); | |
971 | goto alloc_out; | |
972 | } | |
973 | ||
974 | error = aa_alloc_root_ns(); | |
975 | if (error) { | |
976 | AA_ERROR("Unable to allocate default profile namespace\n"); | |
977 | goto alloc_out; | |
978 | } | |
979 | ||
980 | error = apparmor_init_sysctl(); | |
981 | if (error) { | |
982 | AA_ERROR("Unable to register sysctls\n"); | |
983 | goto alloc_out; | |
984 | ||
985 | } | |
986 | ||
987 | error = alloc_buffers(); | |
988 | if (error) { | |
989 | AA_ERROR("Unable to allocate work buffers\n"); | |
990 | goto buffers_out; | |
991 | } | |
992 | ||
993 | error = set_init_ctx(); | |
994 | if (error) { | |
995 | AA_ERROR("Failed to set context on init task\n"); | |
996 | aa_free_root_ns(); | |
997 | goto buffers_out; | |
998 | } | |
999 | security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks), | |
1000 | "apparmor"); | |
1001 | ||
1002 | /* Report that AppArmor successfully initialized */ | |
1003 | apparmor_initialized = 1; | |
1004 | if (aa_g_profile_mode == APPARMOR_COMPLAIN) | |
1005 | aa_info_message("AppArmor initialized: complain mode enabled"); | |
1006 | else if (aa_g_profile_mode == APPARMOR_KILL) | |
1007 | aa_info_message("AppArmor initialized: kill mode enabled"); | |
1008 | else | |
1009 | aa_info_message("AppArmor initialized"); | |
1010 | ||
1011 | return error; | |
1012 | ||
1013 | buffers_out: | |
1014 | destroy_buffers(); | |
1015 | ||
1016 | alloc_out: | |
1017 | aa_destroy_aafs(); | |
1018 | aa_teardown_dfa_engine(); | |
1019 | ||
1020 | apparmor_enabled = 0; | |
1021 | return error; | |
1022 | } | |
1023 | ||
1024 | security_initcall(apparmor_init); |