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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/security.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 <net/sock.h> | |
26 | ||
27 | #include "include/apparmor.h" | |
28 | #include "include/apparmorfs.h" | |
29 | #include "include/audit.h" | |
30 | #include "include/capability.h" | |
31 | #include "include/context.h" | |
32 | #include "include/file.h" | |
33 | #include "include/ipc.h" | |
34 | #include "include/path.h" | |
35 | #include "include/policy.h" | |
36 | #include "include/procattr.h" | |
37 | ||
38 | /* Flag indicating whether initialization completed */ | |
39 | int apparmor_initialized __initdata; | |
40 | ||
41 | /* | |
42 | * LSM hook functions | |
43 | */ | |
44 | ||
45 | /* | |
46 | * free the associated aa_task_cxt and put its profiles | |
47 | */ | |
48 | static void apparmor_cred_free(struct cred *cred) | |
49 | { | |
50 | aa_free_task_context(cred->security); | |
51 | cred->security = NULL; | |
52 | } | |
53 | ||
54 | /* | |
55 | * allocate the apparmor part of blank credentials | |
56 | */ | |
57 | static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp) | |
58 | { | |
59 | /* freed by apparmor_cred_free */ | |
60 | struct aa_task_cxt *cxt = aa_alloc_task_context(gfp); | |
61 | if (!cxt) | |
62 | return -ENOMEM; | |
63 | ||
64 | cred->security = cxt; | |
65 | return 0; | |
66 | } | |
67 | ||
68 | /* | |
69 | * prepare new aa_task_cxt for modification by prepare_cred block | |
70 | */ | |
71 | static int apparmor_cred_prepare(struct cred *new, const struct cred *old, | |
72 | gfp_t gfp) | |
73 | { | |
74 | /* freed by apparmor_cred_free */ | |
75 | struct aa_task_cxt *cxt = aa_alloc_task_context(gfp); | |
76 | if (!cxt) | |
77 | return -ENOMEM; | |
78 | ||
79 | aa_dup_task_context(cxt, old->security); | |
80 | new->security = cxt; | |
81 | return 0; | |
82 | } | |
83 | ||
84 | /* | |
85 | * transfer the apparmor data to a blank set of creds | |
86 | */ | |
87 | static void apparmor_cred_transfer(struct cred *new, const struct cred *old) | |
88 | { | |
89 | const struct aa_task_cxt *old_cxt = old->security; | |
90 | struct aa_task_cxt *new_cxt = new->security; | |
91 | ||
92 | aa_dup_task_context(new_cxt, old_cxt); | |
93 | } | |
94 | ||
95 | static int apparmor_ptrace_access_check(struct task_struct *child, | |
96 | unsigned int mode) | |
97 | { | |
98 | int error = cap_ptrace_access_check(child, mode); | |
99 | if (error) | |
100 | return error; | |
101 | ||
102 | return aa_ptrace(current, child, mode); | |
103 | } | |
104 | ||
105 | static int apparmor_ptrace_traceme(struct task_struct *parent) | |
106 | { | |
107 | int error = cap_ptrace_traceme(parent); | |
108 | if (error) | |
109 | return error; | |
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 | *effective = cred->cap_effective; | |
126 | *inheritable = cred->cap_inheritable; | |
127 | *permitted = cred->cap_permitted; | |
128 | ||
129 | if (!unconfined(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(struct task_struct *task, const struct cred *cred, | |
139 | int cap, int audit) | |
140 | { | |
141 | struct aa_profile *profile; | |
142 | /* cap_capable returns 0 on success, else -EPERM */ | |
143 | int error = cap_capable(task, cred, cap, audit); | |
144 | if (!error) { | |
145 | profile = aa_cred_profile(cred); | |
146 | if (!unconfined(profile)) | |
147 | error = aa_capable(task, profile, cap, audit); | |
148 | } | |
149 | return error; | |
150 | } | |
151 | ||
152 | /** | |
153 | * common_perm - basic common permission check wrapper fn for paths | |
154 | * @op: operation being checked | |
155 | * @path: path to check permission of (NOT NULL) | |
156 | * @mask: requested permissions mask | |
157 | * @cond: conditional info for the permission request (NOT NULL) | |
158 | * | |
159 | * Returns: %0 else error code if error or permission denied | |
160 | */ | |
161 | static int common_perm(int op, struct path *path, u32 mask, | |
162 | struct path_cond *cond) | |
163 | { | |
164 | struct aa_profile *profile; | |
165 | int error = 0; | |
166 | ||
167 | profile = __aa_current_profile(); | |
168 | if (!unconfined(profile)) | |
169 | error = aa_path_perm(op, profile, path, 0, mask, cond); | |
170 | ||
171 | return error; | |
172 | } | |
173 | ||
174 | /** | |
175 | * common_perm_dir_dentry - common permission wrapper when path is dir, dentry | |
176 | * @op: operation being checked | |
177 | * @dir: directory of the dentry (NOT NULL) | |
178 | * @dentry: dentry to check (NOT NULL) | |
179 | * @mask: requested permissions mask | |
180 | * @cond: conditional info for the permission request (NOT NULL) | |
181 | * | |
182 | * Returns: %0 else error code if error or permission denied | |
183 | */ | |
184 | static int common_perm_dir_dentry(int op, struct path *dir, | |
185 | struct dentry *dentry, u32 mask, | |
186 | struct path_cond *cond) | |
187 | { | |
188 | struct path path = { dir->mnt, dentry }; | |
189 | ||
190 | return common_perm(op, &path, mask, cond); | |
191 | } | |
192 | ||
193 | /** | |
194 | * common_perm_mnt_dentry - common permission wrapper when mnt, dentry | |
195 | * @op: operation being checked | |
196 | * @mnt: mount point of dentry (NOT NULL) | |
197 | * @dentry: dentry to check (NOT NULL) | |
198 | * @mask: requested permissions mask | |
199 | * | |
200 | * Returns: %0 else error code if error or permission denied | |
201 | */ | |
202 | static int common_perm_mnt_dentry(int op, struct vfsmount *mnt, | |
203 | struct dentry *dentry, u32 mask) | |
204 | { | |
205 | struct path path = { mnt, dentry }; | |
206 | struct path_cond cond = { dentry->d_inode->i_uid, | |
207 | dentry->d_inode->i_mode | |
208 | }; | |
209 | ||
210 | return common_perm(op, &path, mask, &cond); | |
211 | } | |
212 | ||
213 | /** | |
214 | * common_perm_rm - common permission wrapper for operations doing rm | |
215 | * @op: operation being checked | |
216 | * @dir: directory that the dentry is in (NOT NULL) | |
217 | * @dentry: dentry being rm'd (NOT NULL) | |
218 | * @mask: requested permission mask | |
219 | * | |
220 | * Returns: %0 else error code if error or permission denied | |
221 | */ | |
222 | static int common_perm_rm(int op, struct path *dir, | |
223 | struct dentry *dentry, u32 mask) | |
224 | { | |
225 | struct inode *inode = dentry->d_inode; | |
226 | struct path_cond cond = { }; | |
227 | ||
228 | if (!inode || !dir->mnt || !mediated_filesystem(inode)) | |
229 | return 0; | |
230 | ||
231 | cond.uid = inode->i_uid; | |
232 | cond.mode = inode->i_mode; | |
233 | ||
234 | return common_perm_dir_dentry(op, dir, dentry, mask, &cond); | |
235 | } | |
236 | ||
237 | /** | |
238 | * common_perm_create - common permission wrapper for operations doing create | |
239 | * @op: operation being checked | |
240 | * @dir: directory that dentry will be created in (NOT NULL) | |
241 | * @dentry: dentry to create (NOT NULL) | |
242 | * @mask: request permission mask | |
243 | * @mode: created file mode | |
244 | * | |
245 | * Returns: %0 else error code if error or permission denied | |
246 | */ | |
247 | static int common_perm_create(int op, struct path *dir, struct dentry *dentry, | |
248 | u32 mask, umode_t mode) | |
249 | { | |
250 | struct path_cond cond = { current_fsuid(), mode }; | |
251 | ||
252 | if (!dir->mnt || !mediated_filesystem(dir->dentry->d_inode)) | |
253 | return 0; | |
254 | ||
255 | return common_perm_dir_dentry(op, dir, dentry, mask, &cond); | |
256 | } | |
257 | ||
258 | static int apparmor_path_unlink(struct path *dir, struct dentry *dentry) | |
259 | { | |
260 | return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE); | |
261 | } | |
262 | ||
263 | static int apparmor_path_mkdir(struct path *dir, struct dentry *dentry, | |
264 | int mode) | |
265 | { | |
266 | return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE, | |
267 | S_IFDIR); | |
268 | } | |
269 | ||
270 | static int apparmor_path_rmdir(struct path *dir, struct dentry *dentry) | |
271 | { | |
272 | return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE); | |
273 | } | |
274 | ||
275 | static int apparmor_path_mknod(struct path *dir, struct dentry *dentry, | |
276 | int mode, unsigned int dev) | |
277 | { | |
278 | return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode); | |
279 | } | |
280 | ||
281 | static int apparmor_path_truncate(struct path *path, loff_t length, | |
282 | unsigned int time_attrs) | |
283 | { | |
284 | struct path_cond cond = { path->dentry->d_inode->i_uid, | |
285 | path->dentry->d_inode->i_mode | |
286 | }; | |
287 | ||
288 | if (!path->mnt || !mediated_filesystem(path->dentry->d_inode)) | |
289 | return 0; | |
290 | ||
291 | return common_perm(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE, | |
292 | &cond); | |
293 | } | |
294 | ||
295 | static int apparmor_path_symlink(struct path *dir, struct dentry *dentry, | |
296 | const char *old_name) | |
297 | { | |
298 | return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE, | |
299 | S_IFLNK); | |
300 | } | |
301 | ||
302 | static int apparmor_path_link(struct dentry *old_dentry, struct path *new_dir, | |
303 | struct dentry *new_dentry) | |
304 | { | |
305 | struct aa_profile *profile; | |
306 | int error = 0; | |
307 | ||
308 | if (!mediated_filesystem(old_dentry->d_inode)) | |
309 | return 0; | |
310 | ||
311 | profile = aa_current_profile(); | |
312 | if (!unconfined(profile)) | |
313 | error = aa_path_link(profile, old_dentry, new_dir, new_dentry); | |
314 | return error; | |
315 | } | |
316 | ||
317 | static int apparmor_path_rename(struct path *old_dir, struct dentry *old_dentry, | |
318 | struct path *new_dir, struct dentry *new_dentry) | |
319 | { | |
320 | struct aa_profile *profile; | |
321 | int error = 0; | |
322 | ||
323 | if (!mediated_filesystem(old_dentry->d_inode)) | |
324 | return 0; | |
325 | ||
326 | profile = aa_current_profile(); | |
327 | if (!unconfined(profile)) { | |
328 | struct path old_path = { old_dir->mnt, old_dentry }; | |
329 | struct path new_path = { new_dir->mnt, new_dentry }; | |
330 | struct path_cond cond = { old_dentry->d_inode->i_uid, | |
331 | old_dentry->d_inode->i_mode | |
332 | }; | |
333 | ||
334 | error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0, | |
335 | MAY_READ | AA_MAY_META_READ | MAY_WRITE | | |
336 | AA_MAY_META_WRITE | AA_MAY_DELETE, | |
337 | &cond); | |
338 | if (!error) | |
339 | error = aa_path_perm(OP_RENAME_DEST, profile, &new_path, | |
340 | 0, MAY_WRITE | AA_MAY_META_WRITE | | |
341 | AA_MAY_CREATE, &cond); | |
342 | ||
343 | } | |
344 | return error; | |
345 | } | |
346 | ||
347 | static int apparmor_path_chmod(struct dentry *dentry, struct vfsmount *mnt, | |
348 | mode_t mode) | |
349 | { | |
350 | if (!mediated_filesystem(dentry->d_inode)) | |
351 | return 0; | |
352 | ||
353 | return common_perm_mnt_dentry(OP_CHMOD, mnt, dentry, AA_MAY_CHMOD); | |
354 | } | |
355 | ||
356 | static int apparmor_path_chown(struct path *path, uid_t uid, gid_t gid) | |
357 | { | |
358 | struct path_cond cond = { path->dentry->d_inode->i_uid, | |
359 | path->dentry->d_inode->i_mode | |
360 | }; | |
361 | ||
362 | if (!mediated_filesystem(path->dentry->d_inode)) | |
363 | return 0; | |
364 | ||
365 | return common_perm(OP_CHOWN, path, AA_MAY_CHOWN, &cond); | |
366 | } | |
367 | ||
368 | static int apparmor_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) | |
369 | { | |
370 | if (!mediated_filesystem(dentry->d_inode)) | |
371 | return 0; | |
372 | ||
373 | return common_perm_mnt_dentry(OP_GETATTR, mnt, dentry, | |
374 | AA_MAY_META_READ); | |
375 | } | |
376 | ||
377 | static int apparmor_dentry_open(struct file *file, const struct cred *cred) | |
378 | { | |
379 | struct aa_file_cxt *fcxt = file->f_security; | |
380 | struct aa_profile *profile; | |
381 | int error = 0; | |
382 | ||
383 | if (!mediated_filesystem(file->f_path.dentry->d_inode)) | |
384 | return 0; | |
385 | ||
386 | /* If in exec, permission is handled by bprm hooks. | |
387 | * Cache permissions granted by the previous exec check, with | |
388 | * implicit read and executable mmap which are required to | |
389 | * actually execute the image. | |
390 | */ | |
391 | if (current->in_execve) { | |
392 | fcxt->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP; | |
393 | return 0; | |
394 | } | |
395 | ||
396 | profile = aa_cred_profile(cred); | |
397 | if (!unconfined(profile)) { | |
398 | struct inode *inode = file->f_path.dentry->d_inode; | |
399 | struct path_cond cond = { inode->i_uid, inode->i_mode }; | |
400 | ||
401 | error = aa_path_perm(OP_OPEN, profile, &file->f_path, 0, | |
402 | aa_map_file_to_perms(file), &cond); | |
403 | /* todo cache full allowed permissions set and state */ | |
404 | fcxt->allow = aa_map_file_to_perms(file); | |
405 | } | |
406 | ||
407 | return error; | |
408 | } | |
409 | ||
410 | static int apparmor_file_alloc_security(struct file *file) | |
411 | { | |
412 | /* freed by apparmor_file_free_security */ | |
413 | file->f_security = aa_alloc_file_context(GFP_KERNEL); | |
414 | if (!file->f_security) | |
415 | return -ENOMEM; | |
416 | return 0; | |
417 | ||
418 | } | |
419 | ||
420 | static void apparmor_file_free_security(struct file *file) | |
421 | { | |
422 | struct aa_file_cxt *cxt = file->f_security; | |
423 | ||
424 | aa_free_file_context(cxt); | |
425 | } | |
426 | ||
427 | static int common_file_perm(int op, struct file *file, u32 mask) | |
428 | { | |
429 | struct aa_file_cxt *fcxt = file->f_security; | |
430 | struct aa_profile *profile, *fprofile = aa_cred_profile(file->f_cred); | |
431 | int error = 0; | |
432 | ||
433 | BUG_ON(!fprofile); | |
434 | ||
435 | if (!file->f_path.mnt || | |
436 | !mediated_filesystem(file->f_path.dentry->d_inode)) | |
437 | return 0; | |
438 | ||
439 | profile = __aa_current_profile(); | |
440 | ||
441 | /* revalidate access, if task is unconfined, or the cached cred | |
442 | * doesn't match or if the request is for more permissions than | |
443 | * was granted. | |
444 | * | |
445 | * Note: the test for !unconfined(fprofile) is to handle file | |
446 | * delegation from unconfined tasks | |
447 | */ | |
448 | if (!unconfined(profile) && !unconfined(fprofile) && | |
449 | ((fprofile != profile) || (mask & ~fcxt->allow))) | |
450 | error = aa_file_perm(op, profile, file, mask); | |
451 | ||
452 | return error; | |
453 | } | |
454 | ||
455 | static int apparmor_file_permission(struct file *file, int mask) | |
456 | { | |
457 | return common_file_perm(OP_FPERM, file, mask); | |
458 | } | |
459 | ||
460 | static int apparmor_file_lock(struct file *file, unsigned int cmd) | |
461 | { | |
462 | u32 mask = AA_MAY_LOCK; | |
463 | ||
464 | if (cmd == F_WRLCK) | |
465 | mask |= MAY_WRITE; | |
466 | ||
467 | return common_file_perm(OP_FLOCK, file, mask); | |
468 | } | |
469 | ||
470 | static int common_mmap(int op, struct file *file, unsigned long prot, | |
471 | unsigned long flags) | |
472 | { | |
473 | struct dentry *dentry; | |
474 | int mask = 0; | |
475 | ||
476 | if (!file || !file->f_security) | |
477 | return 0; | |
478 | ||
479 | if (prot & PROT_READ) | |
480 | mask |= MAY_READ; | |
481 | /* | |
482 | * Private mappings don't require write perms since they don't | |
483 | * write back to the files | |
484 | */ | |
485 | if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE)) | |
486 | mask |= MAY_WRITE; | |
487 | if (prot & PROT_EXEC) | |
488 | mask |= AA_EXEC_MMAP; | |
489 | ||
490 | dentry = file->f_path.dentry; | |
491 | return common_file_perm(op, file, mask); | |
492 | } | |
493 | ||
494 | static int apparmor_file_mmap(struct file *file, unsigned long reqprot, | |
495 | unsigned long prot, unsigned long flags, | |
496 | unsigned long addr, unsigned long addr_only) | |
497 | { | |
498 | int rc = 0; | |
499 | ||
500 | /* do DAC check */ | |
501 | rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only); | |
502 | if (rc || addr_only) | |
503 | return rc; | |
504 | ||
505 | return common_mmap(OP_FMMAP, file, prot, flags); | |
506 | } | |
507 | ||
508 | static int apparmor_file_mprotect(struct vm_area_struct *vma, | |
509 | unsigned long reqprot, unsigned long prot) | |
510 | { | |
511 | return common_mmap(OP_FMPROT, vma->vm_file, prot, | |
512 | !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0); | |
513 | } | |
514 | ||
515 | static int apparmor_getprocattr(struct task_struct *task, char *name, | |
516 | char **value) | |
517 | { | |
518 | int error = -ENOENT; | |
519 | struct aa_profile *profile; | |
520 | /* released below */ | |
521 | const struct cred *cred = get_task_cred(task); | |
522 | struct aa_task_cxt *cxt = cred->security; | |
523 | profile = aa_cred_profile(cred); | |
524 | ||
525 | if (strcmp(name, "current") == 0) | |
526 | error = aa_getprocattr(aa_newest_version(cxt->profile), | |
527 | value); | |
528 | else if (strcmp(name, "prev") == 0 && cxt->previous) | |
529 | error = aa_getprocattr(aa_newest_version(cxt->previous), | |
530 | value); | |
531 | else if (strcmp(name, "exec") == 0 && cxt->onexec) | |
532 | error = aa_getprocattr(aa_newest_version(cxt->onexec), | |
533 | value); | |
534 | else | |
535 | error = -EINVAL; | |
536 | ||
537 | put_cred(cred); | |
538 | ||
539 | return error; | |
540 | } | |
541 | ||
542 | static int apparmor_setprocattr(struct task_struct *task, char *name, | |
543 | void *value, size_t size) | |
544 | { | |
545 | char *command, *args = value; | |
546 | size_t arg_size; | |
547 | int error; | |
548 | ||
549 | if (size == 0) | |
550 | return -EINVAL; | |
551 | /* args points to a PAGE_SIZE buffer, AppArmor requires that | |
552 | * the buffer must be null terminated or have size <= PAGE_SIZE -1 | |
553 | * so that AppArmor can null terminate them | |
554 | */ | |
555 | if (args[size - 1] != '\0') { | |
556 | if (size == PAGE_SIZE) | |
557 | return -EINVAL; | |
558 | args[size] = '\0'; | |
559 | } | |
560 | ||
561 | /* task can only write its own attributes */ | |
562 | if (current != task) | |
563 | return -EACCES; | |
564 | ||
565 | args = value; | |
566 | args = strim(args); | |
567 | command = strsep(&args, " "); | |
568 | if (!args) | |
569 | return -EINVAL; | |
570 | args = skip_spaces(args); | |
571 | if (!*args) | |
572 | return -EINVAL; | |
573 | ||
574 | arg_size = size - (args - (char *) value); | |
575 | if (strcmp(name, "current") == 0) { | |
576 | if (strcmp(command, "changehat") == 0) { | |
577 | error = aa_setprocattr_changehat(args, arg_size, | |
578 | !AA_DO_TEST); | |
579 | } else if (strcmp(command, "permhat") == 0) { | |
580 | error = aa_setprocattr_changehat(args, arg_size, | |
581 | AA_DO_TEST); | |
582 | } else if (strcmp(command, "changeprofile") == 0) { | |
583 | error = aa_setprocattr_changeprofile(args, !AA_ONEXEC, | |
584 | !AA_DO_TEST); | |
585 | } else if (strcmp(command, "permprofile") == 0) { | |
586 | error = aa_setprocattr_changeprofile(args, !AA_ONEXEC, | |
587 | AA_DO_TEST); | |
588 | } else if (strcmp(command, "permipc") == 0) { | |
589 | error = aa_setprocattr_permipc(args); | |
590 | } else { | |
591 | struct common_audit_data sa; | |
592 | COMMON_AUDIT_DATA_INIT(&sa, NONE); | |
593 | sa.aad.op = OP_SETPROCATTR; | |
594 | sa.aad.info = name; | |
595 | sa.aad.error = -EINVAL; | |
596 | return aa_audit(AUDIT_APPARMOR_DENIED, NULL, GFP_KERNEL, | |
597 | &sa, NULL); | |
598 | } | |
599 | } else if (strcmp(name, "exec") == 0) { | |
600 | error = aa_setprocattr_changeprofile(args, AA_ONEXEC, | |
601 | !AA_DO_TEST); | |
602 | } else { | |
603 | /* only support the "current" and "exec" process attributes */ | |
604 | return -EINVAL; | |
605 | } | |
606 | if (!error) | |
607 | error = size; | |
608 | return error; | |
609 | } | |
610 | ||
611 | static int apparmor_task_setrlimit(unsigned int resource, | |
612 | struct rlimit *new_rlim) | |
613 | { | |
614 | struct aa_profile *profile = aa_current_profile(); | |
615 | int error = 0; | |
616 | ||
617 | if (!unconfined(profile)) | |
618 | error = aa_task_setrlimit(profile, resource, new_rlim); | |
619 | ||
620 | return error; | |
621 | } | |
622 | ||
623 | static struct security_operations apparmor_ops = { | |
624 | .name = "apparmor", | |
625 | ||
626 | .ptrace_access_check = apparmor_ptrace_access_check, | |
627 | .ptrace_traceme = apparmor_ptrace_traceme, | |
628 | .capget = apparmor_capget, | |
629 | .capable = apparmor_capable, | |
630 | ||
631 | .path_link = apparmor_path_link, | |
632 | .path_unlink = apparmor_path_unlink, | |
633 | .path_symlink = apparmor_path_symlink, | |
634 | .path_mkdir = apparmor_path_mkdir, | |
635 | .path_rmdir = apparmor_path_rmdir, | |
636 | .path_mknod = apparmor_path_mknod, | |
637 | .path_rename = apparmor_path_rename, | |
638 | .path_chmod = apparmor_path_chmod, | |
639 | .path_chown = apparmor_path_chown, | |
640 | .path_truncate = apparmor_path_truncate, | |
641 | .dentry_open = apparmor_dentry_open, | |
642 | .inode_getattr = apparmor_inode_getattr, | |
643 | ||
644 | .file_permission = apparmor_file_permission, | |
645 | .file_alloc_security = apparmor_file_alloc_security, | |
646 | .file_free_security = apparmor_file_free_security, | |
647 | .file_mmap = apparmor_file_mmap, | |
648 | .file_mprotect = apparmor_file_mprotect, | |
649 | .file_lock = apparmor_file_lock, | |
650 | ||
651 | .getprocattr = apparmor_getprocattr, | |
652 | .setprocattr = apparmor_setprocattr, | |
653 | ||
654 | .cred_alloc_blank = apparmor_cred_alloc_blank, | |
655 | .cred_free = apparmor_cred_free, | |
656 | .cred_prepare = apparmor_cred_prepare, | |
657 | .cred_transfer = apparmor_cred_transfer, | |
658 | ||
659 | .bprm_set_creds = apparmor_bprm_set_creds, | |
660 | .bprm_committing_creds = apparmor_bprm_committing_creds, | |
661 | .bprm_committed_creds = apparmor_bprm_committed_creds, | |
662 | .bprm_secureexec = apparmor_bprm_secureexec, | |
663 | ||
664 | .task_setrlimit = apparmor_task_setrlimit, | |
665 | }; | |
666 | ||
667 | /* | |
668 | * AppArmor sysfs module parameters | |
669 | */ | |
670 | ||
671 | static int param_set_aabool(const char *val, struct kernel_param *kp); | |
672 | static int param_get_aabool(char *buffer, struct kernel_param *kp); | |
673 | #define param_check_aabool(name, p) __param_check(name, p, int) | |
674 | ||
675 | static int param_set_aauint(const char *val, struct kernel_param *kp); | |
676 | static int param_get_aauint(char *buffer, struct kernel_param *kp); | |
677 | #define param_check_aauint(name, p) __param_check(name, p, int) | |
678 | ||
679 | static int param_set_aalockpolicy(const char *val, struct kernel_param *kp); | |
680 | static int param_get_aalockpolicy(char *buffer, struct kernel_param *kp); | |
681 | #define param_check_aalockpolicy(name, p) __param_check(name, p, int) | |
682 | ||
683 | static int param_set_audit(const char *val, struct kernel_param *kp); | |
684 | static int param_get_audit(char *buffer, struct kernel_param *kp); | |
685 | #define param_check_audit(name, p) __param_check(name, p, int) | |
686 | ||
687 | static int param_set_mode(const char *val, struct kernel_param *kp); | |
688 | static int param_get_mode(char *buffer, struct kernel_param *kp); | |
689 | #define param_check_mode(name, p) __param_check(name, p, int) | |
690 | ||
691 | /* Flag values, also controllable via /sys/module/apparmor/parameters | |
692 | * We define special types as we want to do additional mediation. | |
693 | */ | |
694 | ||
695 | /* AppArmor global enforcement switch - complain, enforce, kill */ | |
696 | enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE; | |
697 | module_param_call(mode, param_set_mode, param_get_mode, | |
698 | &aa_g_profile_mode, S_IRUSR | S_IWUSR); | |
699 | ||
700 | /* Debug mode */ | |
701 | int aa_g_debug; | |
702 | module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR); | |
703 | ||
704 | /* Audit mode */ | |
705 | enum audit_mode aa_g_audit; | |
706 | module_param_call(audit, param_set_audit, param_get_audit, | |
707 | &aa_g_audit, S_IRUSR | S_IWUSR); | |
708 | ||
709 | /* Determines if audit header is included in audited messages. This | |
710 | * provides more context if the audit daemon is not running | |
711 | */ | |
712 | int aa_g_audit_header = 1; | |
713 | module_param_named(audit_header, aa_g_audit_header, aabool, | |
714 | S_IRUSR | S_IWUSR); | |
715 | ||
716 | /* lock out loading/removal of policy | |
717 | * TODO: add in at boot loading of policy, which is the only way to | |
718 | * load policy, if lock_policy is set | |
719 | */ | |
720 | int aa_g_lock_policy; | |
721 | module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy, | |
722 | S_IRUSR | S_IWUSR); | |
723 | ||
724 | /* Syscall logging mode */ | |
725 | int aa_g_logsyscall; | |
726 | module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR); | |
727 | ||
728 | /* Maximum pathname length before accesses will start getting rejected */ | |
729 | unsigned int aa_g_path_max = 2 * PATH_MAX; | |
730 | module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR); | |
731 | ||
732 | /* Determines how paranoid loading of policy is and how much verification | |
733 | * on the loaded policy is done. | |
734 | */ | |
735 | int aa_g_paranoid_load = 1; | |
736 | module_param_named(paranoid_load, aa_g_paranoid_load, aabool, | |
737 | S_IRUSR | S_IWUSR); | |
738 | ||
739 | /* Boot time disable flag */ | |
740 | static unsigned int apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE; | |
741 | module_param_named(enabled, apparmor_enabled, aabool, S_IRUSR); | |
742 | ||
743 | static int __init apparmor_enabled_setup(char *str) | |
744 | { | |
745 | unsigned long enabled; | |
746 | int error = strict_strtoul(str, 0, &enabled); | |
747 | if (!error) | |
748 | apparmor_enabled = enabled ? 1 : 0; | |
749 | return 1; | |
750 | } | |
751 | ||
752 | __setup("apparmor=", apparmor_enabled_setup); | |
753 | ||
754 | /* set global flag turning off the ability to load policy */ | |
755 | static int param_set_aalockpolicy(const char *val, struct kernel_param *kp) | |
756 | { | |
757 | if (!capable(CAP_MAC_ADMIN)) | |
758 | return -EPERM; | |
759 | if (aa_g_lock_policy) | |
760 | return -EACCES; | |
761 | return param_set_bool(val, kp); | |
762 | } | |
763 | ||
764 | static int param_get_aalockpolicy(char *buffer, struct kernel_param *kp) | |
765 | { | |
766 | if (!capable(CAP_MAC_ADMIN)) | |
767 | return -EPERM; | |
768 | return param_get_bool(buffer, kp); | |
769 | } | |
770 | ||
771 | static int param_set_aabool(const char *val, struct kernel_param *kp) | |
772 | { | |
773 | if (!capable(CAP_MAC_ADMIN)) | |
774 | return -EPERM; | |
775 | return param_set_bool(val, kp); | |
776 | } | |
777 | ||
778 | static int param_get_aabool(char *buffer, struct kernel_param *kp) | |
779 | { | |
780 | if (!capable(CAP_MAC_ADMIN)) | |
781 | return -EPERM; | |
782 | return param_get_bool(buffer, kp); | |
783 | } | |
784 | ||
785 | static int param_set_aauint(const char *val, struct kernel_param *kp) | |
786 | { | |
787 | if (!capable(CAP_MAC_ADMIN)) | |
788 | return -EPERM; | |
789 | return param_set_uint(val, kp); | |
790 | } | |
791 | ||
792 | static int param_get_aauint(char *buffer, struct kernel_param *kp) | |
793 | { | |
794 | if (!capable(CAP_MAC_ADMIN)) | |
795 | return -EPERM; | |
796 | return param_get_uint(buffer, kp); | |
797 | } | |
798 | ||
799 | static int param_get_audit(char *buffer, struct kernel_param *kp) | |
800 | { | |
801 | if (!capable(CAP_MAC_ADMIN)) | |
802 | return -EPERM; | |
803 | ||
804 | if (!apparmor_enabled) | |
805 | return -EINVAL; | |
806 | ||
807 | return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]); | |
808 | } | |
809 | ||
810 | static int param_set_audit(const char *val, struct kernel_param *kp) | |
811 | { | |
812 | int i; | |
813 | if (!capable(CAP_MAC_ADMIN)) | |
814 | return -EPERM; | |
815 | ||
816 | if (!apparmor_enabled) | |
817 | return -EINVAL; | |
818 | ||
819 | if (!val) | |
820 | return -EINVAL; | |
821 | ||
822 | for (i = 0; i < AUDIT_MAX_INDEX; i++) { | |
823 | if (strcmp(val, audit_mode_names[i]) == 0) { | |
824 | aa_g_audit = i; | |
825 | return 0; | |
826 | } | |
827 | } | |
828 | ||
829 | return -EINVAL; | |
830 | } | |
831 | ||
832 | static int param_get_mode(char *buffer, struct kernel_param *kp) | |
833 | { | |
834 | if (!capable(CAP_MAC_ADMIN)) | |
835 | return -EPERM; | |
836 | ||
837 | if (!apparmor_enabled) | |
838 | return -EINVAL; | |
839 | ||
840 | return sprintf(buffer, "%s", profile_mode_names[aa_g_profile_mode]); | |
841 | } | |
842 | ||
843 | static int param_set_mode(const char *val, struct kernel_param *kp) | |
844 | { | |
845 | int i; | |
846 | if (!capable(CAP_MAC_ADMIN)) | |
847 | return -EPERM; | |
848 | ||
849 | if (!apparmor_enabled) | |
850 | return -EINVAL; | |
851 | ||
852 | if (!val) | |
853 | return -EINVAL; | |
854 | ||
855 | for (i = 0; i < APPARMOR_NAMES_MAX_INDEX; i++) { | |
856 | if (strcmp(val, profile_mode_names[i]) == 0) { | |
857 | aa_g_profile_mode = i; | |
858 | return 0; | |
859 | } | |
860 | } | |
861 | ||
862 | return -EINVAL; | |
863 | } | |
864 | ||
865 | /* | |
866 | * AppArmor init functions | |
867 | */ | |
868 | ||
869 | /** | |
870 | * set_init_cxt - set a task context and profile on the first task. | |
871 | * | |
872 | * TODO: allow setting an alternate profile than unconfined | |
873 | */ | |
874 | static int __init set_init_cxt(void) | |
875 | { | |
876 | struct cred *cred = (struct cred *)current->real_cred; | |
877 | struct aa_task_cxt *cxt; | |
878 | ||
879 | cxt = aa_alloc_task_context(GFP_KERNEL); | |
880 | if (!cxt) | |
881 | return -ENOMEM; | |
882 | ||
883 | cxt->profile = aa_get_profile(root_ns->unconfined); | |
884 | cred->security = cxt; | |
885 | ||
886 | return 0; | |
887 | } | |
888 | ||
889 | static int __init apparmor_init(void) | |
890 | { | |
891 | int error; | |
892 | ||
893 | if (!apparmor_enabled || !security_module_enable(&apparmor_ops)) { | |
894 | aa_info_message("AppArmor disabled by boot time parameter"); | |
895 | apparmor_enabled = 0; | |
896 | return 0; | |
897 | } | |
898 | ||
899 | error = aa_alloc_root_ns(); | |
900 | if (error) { | |
901 | AA_ERROR("Unable to allocate default profile namespace\n"); | |
902 | goto alloc_out; | |
903 | } | |
904 | ||
905 | error = set_init_cxt(); | |
906 | if (error) { | |
907 | AA_ERROR("Failed to set context on init task\n"); | |
908 | goto register_security_out; | |
909 | } | |
910 | ||
911 | error = register_security(&apparmor_ops); | |
912 | if (error) { | |
913 | AA_ERROR("Unable to register AppArmor\n"); | |
914 | goto register_security_out; | |
915 | } | |
916 | ||
917 | /* Report that AppArmor successfully initialized */ | |
918 | apparmor_initialized = 1; | |
919 | if (aa_g_profile_mode == APPARMOR_COMPLAIN) | |
920 | aa_info_message("AppArmor initialized: complain mode enabled"); | |
921 | else if (aa_g_profile_mode == APPARMOR_KILL) | |
922 | aa_info_message("AppArmor initialized: kill mode enabled"); | |
923 | else | |
924 | aa_info_message("AppArmor initialized"); | |
925 | ||
926 | return error; | |
927 | ||
928 | register_security_out: | |
929 | aa_free_root_ns(); | |
930 | ||
931 | alloc_out: | |
932 | aa_destroy_aafs(); | |
933 | ||
934 | apparmor_enabled = 0; | |
935 | return error; | |
936 | ||
937 | } | |
938 | ||
939 | security_initcall(apparmor_init); |