Commit | Line | Data |
---|---|---|
2ea3ffb7 JJ |
1 | /* |
2 | * AppArmor security module | |
3 | * | |
4 | * This file contains AppArmor mediation of files | |
5 | * | |
6 | * Copyright (C) 1998-2008 Novell/SUSE | |
7 | * Copyright 2009-2017 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/fs.h> | |
16 | #include <linux/mount.h> | |
17 | #include <linux/namei.h> | |
e262e32d | 18 | #include <uapi/linux/mount.h> |
2ea3ffb7 JJ |
19 | |
20 | #include "include/apparmor.h" | |
21 | #include "include/audit.h" | |
d8889d49 | 22 | #include "include/cred.h" |
2ea3ffb7 JJ |
23 | #include "include/domain.h" |
24 | #include "include/file.h" | |
25 | #include "include/match.h" | |
26 | #include "include/mount.h" | |
27 | #include "include/path.h" | |
28 | #include "include/policy.h" | |
29 | ||
30 | ||
31 | static void audit_mnt_flags(struct audit_buffer *ab, unsigned long flags) | |
32 | { | |
33 | if (flags & MS_RDONLY) | |
34 | audit_log_format(ab, "ro"); | |
35 | else | |
36 | audit_log_format(ab, "rw"); | |
37 | if (flags & MS_NOSUID) | |
38 | audit_log_format(ab, ", nosuid"); | |
39 | if (flags & MS_NODEV) | |
40 | audit_log_format(ab, ", nodev"); | |
41 | if (flags & MS_NOEXEC) | |
42 | audit_log_format(ab, ", noexec"); | |
43 | if (flags & MS_SYNCHRONOUS) | |
44 | audit_log_format(ab, ", sync"); | |
45 | if (flags & MS_REMOUNT) | |
46 | audit_log_format(ab, ", remount"); | |
47 | if (flags & MS_MANDLOCK) | |
48 | audit_log_format(ab, ", mand"); | |
49 | if (flags & MS_DIRSYNC) | |
50 | audit_log_format(ab, ", dirsync"); | |
51 | if (flags & MS_NOATIME) | |
52 | audit_log_format(ab, ", noatime"); | |
53 | if (flags & MS_NODIRATIME) | |
54 | audit_log_format(ab, ", nodiratime"); | |
55 | if (flags & MS_BIND) | |
56 | audit_log_format(ab, flags & MS_REC ? ", rbind" : ", bind"); | |
57 | if (flags & MS_MOVE) | |
58 | audit_log_format(ab, ", move"); | |
59 | if (flags & MS_SILENT) | |
60 | audit_log_format(ab, ", silent"); | |
61 | if (flags & MS_POSIXACL) | |
62 | audit_log_format(ab, ", acl"); | |
63 | if (flags & MS_UNBINDABLE) | |
64 | audit_log_format(ab, flags & MS_REC ? ", runbindable" : | |
65 | ", unbindable"); | |
66 | if (flags & MS_PRIVATE) | |
67 | audit_log_format(ab, flags & MS_REC ? ", rprivate" : | |
68 | ", private"); | |
69 | if (flags & MS_SLAVE) | |
70 | audit_log_format(ab, flags & MS_REC ? ", rslave" : | |
71 | ", slave"); | |
72 | if (flags & MS_SHARED) | |
73 | audit_log_format(ab, flags & MS_REC ? ", rshared" : | |
74 | ", shared"); | |
75 | if (flags & MS_RELATIME) | |
76 | audit_log_format(ab, ", relatime"); | |
77 | if (flags & MS_I_VERSION) | |
78 | audit_log_format(ab, ", iversion"); | |
79 | if (flags & MS_STRICTATIME) | |
80 | audit_log_format(ab, ", strictatime"); | |
81 | if (flags & MS_NOUSER) | |
82 | audit_log_format(ab, ", nouser"); | |
83 | } | |
84 | ||
85 | /** | |
86 | * audit_cb - call back for mount specific audit fields | |
87 | * @ab: audit_buffer (NOT NULL) | |
88 | * @va: audit struct to audit values of (NOT NULL) | |
89 | */ | |
90 | static void audit_cb(struct audit_buffer *ab, void *va) | |
91 | { | |
92 | struct common_audit_data *sa = va; | |
93 | ||
94 | if (aad(sa)->mnt.type) { | |
95 | audit_log_format(ab, " fstype="); | |
96 | audit_log_untrustedstring(ab, aad(sa)->mnt.type); | |
97 | } | |
98 | if (aad(sa)->mnt.src_name) { | |
99 | audit_log_format(ab, " srcname="); | |
100 | audit_log_untrustedstring(ab, aad(sa)->mnt.src_name); | |
101 | } | |
102 | if (aad(sa)->mnt.trans) { | |
103 | audit_log_format(ab, " trans="); | |
104 | audit_log_untrustedstring(ab, aad(sa)->mnt.trans); | |
105 | } | |
106 | if (aad(sa)->mnt.flags) { | |
107 | audit_log_format(ab, " flags=\""); | |
108 | audit_mnt_flags(ab, aad(sa)->mnt.flags); | |
109 | audit_log_format(ab, "\""); | |
110 | } | |
111 | if (aad(sa)->mnt.data) { | |
112 | audit_log_format(ab, " options="); | |
113 | audit_log_untrustedstring(ab, aad(sa)->mnt.data); | |
114 | } | |
115 | } | |
116 | ||
117 | /** | |
118 | * audit_mount - handle the auditing of mount operations | |
119 | * @profile: the profile being enforced (NOT NULL) | |
120 | * @op: operation being mediated (NOT NULL) | |
121 | * @name: name of object being mediated (MAYBE NULL) | |
122 | * @src_name: src_name of object being mediated (MAYBE_NULL) | |
123 | * @type: type of filesystem (MAYBE_NULL) | |
124 | * @trans: name of trans (MAYBE NULL) | |
68a1a0c6 | 125 | * @flags: filesystem independent mount flags |
2ea3ffb7 JJ |
126 | * @data: filesystem mount flags |
127 | * @request: permissions requested | |
128 | * @perms: the permissions computed for the request (NOT NULL) | |
129 | * @info: extra information message (MAYBE NULL) | |
130 | * @error: 0 if operation allowed else failure error code | |
131 | * | |
132 | * Returns: %0 or error on failure | |
133 | */ | |
134 | static int audit_mount(struct aa_profile *profile, const char *op, | |
135 | const char *name, const char *src_name, | |
136 | const char *type, const char *trans, | |
137 | unsigned long flags, const void *data, u32 request, | |
138 | struct aa_perms *perms, const char *info, int error) | |
139 | { | |
140 | int audit_type = AUDIT_APPARMOR_AUTO; | |
141 | DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, op); | |
142 | ||
143 | if (likely(!error)) { | |
144 | u32 mask = perms->audit; | |
145 | ||
146 | if (unlikely(AUDIT_MODE(profile) == AUDIT_ALL)) | |
147 | mask = 0xffff; | |
148 | ||
149 | /* mask off perms that are not being force audited */ | |
150 | request &= mask; | |
151 | ||
152 | if (likely(!request)) | |
153 | return 0; | |
154 | audit_type = AUDIT_APPARMOR_AUDIT; | |
155 | } else { | |
156 | /* only report permissions that were denied */ | |
157 | request = request & ~perms->allow; | |
158 | ||
159 | if (request & perms->kill) | |
160 | audit_type = AUDIT_APPARMOR_KILL; | |
161 | ||
162 | /* quiet known rejects, assumes quiet and kill do not overlap */ | |
163 | if ((request & perms->quiet) && | |
164 | AUDIT_MODE(profile) != AUDIT_NOQUIET && | |
165 | AUDIT_MODE(profile) != AUDIT_ALL) | |
166 | request &= ~perms->quiet; | |
167 | ||
168 | if (!request) | |
169 | return error; | |
170 | } | |
171 | ||
172 | aad(&sa)->name = name; | |
173 | aad(&sa)->mnt.src_name = src_name; | |
174 | aad(&sa)->mnt.type = type; | |
175 | aad(&sa)->mnt.trans = trans; | |
176 | aad(&sa)->mnt.flags = flags; | |
177 | if (data && (perms->audit & AA_AUDIT_DATA)) | |
178 | aad(&sa)->mnt.data = data; | |
179 | aad(&sa)->info = info; | |
180 | aad(&sa)->error = error; | |
181 | ||
182 | return aa_audit(audit_type, profile, &sa, audit_cb); | |
183 | } | |
184 | ||
185 | /** | |
186 | * match_mnt_flags - Do an ordered match on mount flags | |
187 | * @dfa: dfa to match against | |
188 | * @state: state to start in | |
189 | * @flags: mount flags to match against | |
190 | * | |
191 | * Mount flags are encoded as an ordered match. This is done instead of | |
192 | * checking against a simple bitmask, to allow for logical operations | |
193 | * on the flags. | |
194 | * | |
195 | * Returns: next state after flags match | |
196 | */ | |
197 | static unsigned int match_mnt_flags(struct aa_dfa *dfa, unsigned int state, | |
198 | unsigned long flags) | |
199 | { | |
200 | unsigned int i; | |
201 | ||
202 | for (i = 0; i <= 31 ; ++i) { | |
203 | if ((1 << i) & flags) | |
204 | state = aa_dfa_next(dfa, state, i + 1); | |
205 | } | |
206 | ||
207 | return state; | |
208 | } | |
209 | ||
210 | /** | |
211 | * compute_mnt_perms - compute mount permission associated with @state | |
212 | * @dfa: dfa to match against (NOT NULL) | |
213 | * @state: state match finished in | |
214 | * | |
215 | * Returns: mount permissions | |
216 | */ | |
217 | static struct aa_perms compute_mnt_perms(struct aa_dfa *dfa, | |
218 | unsigned int state) | |
219 | { | |
7bba39ae AB |
220 | struct aa_perms perms = { |
221 | .allow = dfa_user_allow(dfa, state), | |
222 | .audit = dfa_user_audit(dfa, state), | |
223 | .quiet = dfa_user_quiet(dfa, state), | |
224 | .xindex = dfa_user_xindex(dfa, state), | |
225 | }; | |
2ea3ffb7 JJ |
226 | |
227 | return perms; | |
228 | } | |
229 | ||
230 | static const char * const mnt_info_table[] = { | |
231 | "match succeeded", | |
232 | "failed mntpnt match", | |
233 | "failed srcname match", | |
234 | "failed type match", | |
235 | "failed flags match", | |
236 | "failed data match" | |
237 | }; | |
238 | ||
239 | /* | |
240 | * Returns 0 on success else element that match failed in, this is the | |
241 | * index into the mnt_info_table above | |
242 | */ | |
243 | static int do_match_mnt(struct aa_dfa *dfa, unsigned int start, | |
244 | const char *mntpnt, const char *devname, | |
245 | const char *type, unsigned long flags, | |
246 | void *data, bool binary, struct aa_perms *perms) | |
247 | { | |
248 | unsigned int state; | |
249 | ||
250 | AA_BUG(!dfa); | |
251 | AA_BUG(!perms); | |
252 | ||
253 | state = aa_dfa_match(dfa, start, mntpnt); | |
254 | state = aa_dfa_null_transition(dfa, state); | |
255 | if (!state) | |
256 | return 1; | |
257 | ||
258 | if (devname) | |
259 | state = aa_dfa_match(dfa, state, devname); | |
260 | state = aa_dfa_null_transition(dfa, state); | |
261 | if (!state) | |
262 | return 2; | |
263 | ||
264 | if (type) | |
265 | state = aa_dfa_match(dfa, state, type); | |
266 | state = aa_dfa_null_transition(dfa, state); | |
267 | if (!state) | |
268 | return 3; | |
269 | ||
270 | state = match_mnt_flags(dfa, state, flags); | |
271 | if (!state) | |
272 | return 4; | |
273 | *perms = compute_mnt_perms(dfa, state); | |
274 | if (perms->allow & AA_MAY_MOUNT) | |
275 | return 0; | |
276 | ||
277 | /* only match data if not binary and the DFA flags data is expected */ | |
278 | if (data && !binary && (perms->allow & AA_MNT_CONT_MATCH)) { | |
279 | state = aa_dfa_null_transition(dfa, state); | |
280 | if (!state) | |
281 | return 4; | |
282 | ||
283 | state = aa_dfa_match(dfa, state, data); | |
284 | if (!state) | |
285 | return 5; | |
286 | *perms = compute_mnt_perms(dfa, state); | |
287 | if (perms->allow & AA_MAY_MOUNT) | |
288 | return 0; | |
289 | } | |
290 | ||
291 | /* failed at end of flags match */ | |
292 | return 4; | |
293 | } | |
294 | ||
295 | ||
296 | static int path_flags(struct aa_profile *profile, const struct path *path) | |
297 | { | |
298 | AA_BUG(!profile); | |
299 | AA_BUG(!path); | |
300 | ||
301 | return profile->path_flags | | |
302 | (S_ISDIR(path->dentry->d_inode->i_mode) ? PATH_IS_DIR : 0); | |
303 | } | |
304 | ||
305 | /** | |
306 | * match_mnt_path_str - handle path matching for mount | |
307 | * @profile: the confining profile | |
308 | * @mntpath: for the mntpnt (NOT NULL) | |
309 | * @buffer: buffer to be used to lookup mntpath | |
310 | * @devnme: string for the devname/src_name (MAY BE NULL OR ERRPTR) | |
311 | * @type: string for the dev type (MAYBE NULL) | |
312 | * @flags: mount flags to match | |
313 | * @data: fs mount data (MAYBE NULL) | |
314 | * @binary: whether @data is binary | |
315 | * @devinfo: error str if (IS_ERR(@devname)) | |
316 | * | |
317 | * Returns: 0 on success else error | |
318 | */ | |
319 | static int match_mnt_path_str(struct aa_profile *profile, | |
320 | const struct path *mntpath, char *buffer, | |
321 | const char *devname, const char *type, | |
322 | unsigned long flags, void *data, bool binary, | |
323 | const char *devinfo) | |
324 | { | |
325 | struct aa_perms perms = { }; | |
326 | const char *mntpnt = NULL, *info = NULL; | |
327 | int pos, error; | |
328 | ||
329 | AA_BUG(!profile); | |
330 | AA_BUG(!mntpath); | |
331 | AA_BUG(!buffer); | |
332 | ||
5b9f57cf JJ |
333 | if (!PROFILE_MEDIATES(profile, AA_CLASS_MOUNT)) |
334 | return 0; | |
335 | ||
2ea3ffb7 JJ |
336 | error = aa_path_name(mntpath, path_flags(profile, mntpath), buffer, |
337 | &mntpnt, &info, profile->disconnected); | |
338 | if (error) | |
339 | goto audit; | |
340 | if (IS_ERR(devname)) { | |
341 | error = PTR_ERR(devname); | |
342 | devname = NULL; | |
343 | info = devinfo; | |
344 | goto audit; | |
345 | } | |
346 | ||
347 | error = -EACCES; | |
348 | pos = do_match_mnt(profile->policy.dfa, | |
349 | profile->policy.start[AA_CLASS_MOUNT], | |
350 | mntpnt, devname, type, flags, data, binary, &perms); | |
351 | if (pos) { | |
352 | info = mnt_info_table[pos]; | |
353 | goto audit; | |
354 | } | |
355 | error = 0; | |
356 | ||
357 | audit: | |
358 | return audit_mount(profile, OP_MOUNT, mntpnt, devname, type, NULL, | |
359 | flags, data, AA_MAY_MOUNT, &perms, info, error); | |
360 | } | |
361 | ||
362 | /** | |
363 | * match_mnt - handle path matching for mount | |
364 | * @profile: the confining profile | |
365 | * @mntpath: for the mntpnt (NOT NULL) | |
366 | * @buffer: buffer to be used to lookup mntpath | |
367 | * @devpath: path devname/src_name (MAYBE NULL) | |
368 | * @devbuffer: buffer to be used to lookup devname/src_name | |
369 | * @type: string for the dev type (MAYBE NULL) | |
370 | * @flags: mount flags to match | |
371 | * @data: fs mount data (MAYBE NULL) | |
372 | * @binary: whether @data is binary | |
373 | * | |
374 | * Returns: 0 on success else error | |
375 | */ | |
376 | static int match_mnt(struct aa_profile *profile, const struct path *path, | |
377 | char *buffer, struct path *devpath, char *devbuffer, | |
378 | const char *type, unsigned long flags, void *data, | |
379 | bool binary) | |
380 | { | |
381 | const char *devname = NULL, *info = NULL; | |
382 | int error = -EACCES; | |
383 | ||
384 | AA_BUG(!profile); | |
385 | AA_BUG(devpath && !devbuffer); | |
386 | ||
5b9f57cf JJ |
387 | if (!PROFILE_MEDIATES(profile, AA_CLASS_MOUNT)) |
388 | return 0; | |
389 | ||
2ea3ffb7 JJ |
390 | if (devpath) { |
391 | error = aa_path_name(devpath, path_flags(profile, devpath), | |
392 | devbuffer, &devname, &info, | |
393 | profile->disconnected); | |
394 | if (error) | |
395 | devname = ERR_PTR(error); | |
396 | } | |
397 | ||
398 | return match_mnt_path_str(profile, path, buffer, devname, type, flags, | |
399 | data, binary, info); | |
400 | } | |
401 | ||
402 | int aa_remount(struct aa_label *label, const struct path *path, | |
403 | unsigned long flags, void *data) | |
404 | { | |
405 | struct aa_profile *profile; | |
406 | char *buffer = NULL; | |
407 | bool binary; | |
408 | int error; | |
409 | ||
410 | AA_BUG(!label); | |
411 | AA_BUG(!path); | |
412 | ||
413 | binary = path->dentry->d_sb->s_type->fs_flags & FS_BINARY_MOUNTDATA; | |
414 | ||
415 | get_buffers(buffer); | |
416 | error = fn_for_each_confined(label, profile, | |
417 | match_mnt(profile, path, buffer, NULL, NULL, NULL, | |
418 | flags, data, binary)); | |
419 | put_buffers(buffer); | |
420 | ||
421 | return error; | |
422 | } | |
423 | ||
424 | int aa_bind_mount(struct aa_label *label, const struct path *path, | |
425 | const char *dev_name, unsigned long flags) | |
426 | { | |
427 | struct aa_profile *profile; | |
428 | char *buffer = NULL, *old_buffer = NULL; | |
429 | struct path old_path; | |
430 | int error; | |
431 | ||
432 | AA_BUG(!label); | |
433 | AA_BUG(!path); | |
434 | ||
435 | if (!dev_name || !*dev_name) | |
436 | return -EINVAL; | |
437 | ||
438 | flags &= MS_REC | MS_BIND; | |
439 | ||
440 | error = kern_path(dev_name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &old_path); | |
441 | if (error) | |
442 | return error; | |
443 | ||
444 | get_buffers(buffer, old_buffer); | |
445 | error = fn_for_each_confined(label, profile, | |
446 | match_mnt(profile, path, buffer, &old_path, old_buffer, | |
447 | NULL, flags, NULL, false)); | |
448 | put_buffers(buffer, old_buffer); | |
449 | path_put(&old_path); | |
450 | ||
451 | return error; | |
452 | } | |
453 | ||
454 | int aa_mount_change_type(struct aa_label *label, const struct path *path, | |
455 | unsigned long flags) | |
456 | { | |
457 | struct aa_profile *profile; | |
458 | char *buffer = NULL; | |
459 | int error; | |
460 | ||
461 | AA_BUG(!label); | |
462 | AA_BUG(!path); | |
463 | ||
464 | /* These are the flags allowed by do_change_type() */ | |
465 | flags &= (MS_REC | MS_SILENT | MS_SHARED | MS_PRIVATE | MS_SLAVE | | |
466 | MS_UNBINDABLE); | |
467 | ||
468 | get_buffers(buffer); | |
469 | error = fn_for_each_confined(label, profile, | |
470 | match_mnt(profile, path, buffer, NULL, NULL, NULL, | |
471 | flags, NULL, false)); | |
472 | put_buffers(buffer); | |
473 | ||
474 | return error; | |
475 | } | |
476 | ||
477 | int aa_move_mount(struct aa_label *label, const struct path *path, | |
478 | const char *orig_name) | |
479 | { | |
480 | struct aa_profile *profile; | |
481 | char *buffer = NULL, *old_buffer = NULL; | |
482 | struct path old_path; | |
483 | int error; | |
484 | ||
485 | AA_BUG(!label); | |
486 | AA_BUG(!path); | |
487 | ||
488 | if (!orig_name || !*orig_name) | |
489 | return -EINVAL; | |
490 | ||
491 | error = kern_path(orig_name, LOOKUP_FOLLOW, &old_path); | |
492 | if (error) | |
493 | return error; | |
494 | ||
495 | get_buffers(buffer, old_buffer); | |
496 | error = fn_for_each_confined(label, profile, | |
497 | match_mnt(profile, path, buffer, &old_path, old_buffer, | |
498 | NULL, MS_MOVE, NULL, false)); | |
499 | put_buffers(buffer, old_buffer); | |
500 | path_put(&old_path); | |
501 | ||
502 | return error; | |
503 | } | |
504 | ||
505 | int aa_new_mount(struct aa_label *label, const char *dev_name, | |
506 | const struct path *path, const char *type, unsigned long flags, | |
507 | void *data) | |
508 | { | |
509 | struct aa_profile *profile; | |
510 | char *buffer = NULL, *dev_buffer = NULL; | |
511 | bool binary = true; | |
512 | int error; | |
513 | int requires_dev = 0; | |
514 | struct path tmp_path, *dev_path = NULL; | |
515 | ||
516 | AA_BUG(!label); | |
517 | AA_BUG(!path); | |
518 | ||
519 | if (type) { | |
520 | struct file_system_type *fstype; | |
521 | ||
522 | fstype = get_fs_type(type); | |
523 | if (!fstype) | |
524 | return -ENODEV; | |
525 | binary = fstype->fs_flags & FS_BINARY_MOUNTDATA; | |
526 | requires_dev = fstype->fs_flags & FS_REQUIRES_DEV; | |
527 | put_filesystem(fstype); | |
528 | ||
529 | if (requires_dev) { | |
530 | if (!dev_name || !*dev_name) | |
531 | return -ENOENT; | |
532 | ||
533 | error = kern_path(dev_name, LOOKUP_FOLLOW, &tmp_path); | |
534 | if (error) | |
535 | return error; | |
536 | dev_path = &tmp_path; | |
537 | } | |
538 | } | |
539 | ||
540 | get_buffers(buffer, dev_buffer); | |
541 | if (dev_path) { | |
542 | error = fn_for_each_confined(label, profile, | |
543 | match_mnt(profile, path, buffer, dev_path, dev_buffer, | |
544 | type, flags, data, binary)); | |
545 | } else { | |
546 | error = fn_for_each_confined(label, profile, | |
547 | match_mnt_path_str(profile, path, buffer, dev_name, | |
548 | type, flags, data, binary, NULL)); | |
549 | } | |
550 | put_buffers(buffer, dev_buffer); | |
551 | if (dev_path) | |
552 | path_put(dev_path); | |
553 | ||
554 | return error; | |
555 | } | |
556 | ||
557 | static int profile_umount(struct aa_profile *profile, struct path *path, | |
558 | char *buffer) | |
559 | { | |
560 | struct aa_perms perms = { }; | |
561 | const char *name = NULL, *info = NULL; | |
562 | unsigned int state; | |
563 | int error; | |
564 | ||
565 | AA_BUG(!profile); | |
566 | AA_BUG(!path); | |
567 | ||
5b9f57cf JJ |
568 | if (!PROFILE_MEDIATES(profile, AA_CLASS_MOUNT)) |
569 | return 0; | |
570 | ||
2ea3ffb7 JJ |
571 | error = aa_path_name(path, path_flags(profile, path), buffer, &name, |
572 | &info, profile->disconnected); | |
573 | if (error) | |
574 | goto audit; | |
575 | ||
576 | state = aa_dfa_match(profile->policy.dfa, | |
577 | profile->policy.start[AA_CLASS_MOUNT], | |
578 | name); | |
579 | perms = compute_mnt_perms(profile->policy.dfa, state); | |
580 | if (AA_MAY_UMOUNT & ~perms.allow) | |
581 | error = -EACCES; | |
582 | ||
583 | audit: | |
584 | return audit_mount(profile, OP_UMOUNT, name, NULL, NULL, NULL, 0, NULL, | |
585 | AA_MAY_UMOUNT, &perms, info, error); | |
586 | } | |
587 | ||
588 | int aa_umount(struct aa_label *label, struct vfsmount *mnt, int flags) | |
589 | { | |
590 | struct aa_profile *profile; | |
591 | char *buffer = NULL; | |
592 | int error; | |
593 | struct path path = { .mnt = mnt, .dentry = mnt->mnt_root }; | |
594 | ||
595 | AA_BUG(!label); | |
596 | AA_BUG(!mnt); | |
597 | ||
598 | get_buffers(buffer); | |
599 | error = fn_for_each_confined(label, profile, | |
600 | profile_umount(profile, &path, buffer)); | |
601 | put_buffers(buffer); | |
602 | ||
603 | return error; | |
604 | } | |
605 | ||
606 | /* helper fn for transition on pivotroot | |
607 | * | |
608 | * Returns: label for transition or ERR_PTR. Does not return NULL | |
609 | */ | |
610 | static struct aa_label *build_pivotroot(struct aa_profile *profile, | |
611 | const struct path *new_path, | |
612 | char *new_buffer, | |
613 | const struct path *old_path, | |
614 | char *old_buffer) | |
615 | { | |
616 | const char *old_name, *new_name = NULL, *info = NULL; | |
617 | const char *trans_name = NULL; | |
618 | struct aa_perms perms = { }; | |
619 | unsigned int state; | |
620 | int error; | |
621 | ||
622 | AA_BUG(!profile); | |
623 | AA_BUG(!new_path); | |
624 | AA_BUG(!old_path); | |
625 | ||
5b9f57cf JJ |
626 | if (profile_unconfined(profile) || |
627 | !PROFILE_MEDIATES(profile, AA_CLASS_MOUNT)) | |
2ea3ffb7 JJ |
628 | return aa_get_newest_label(&profile->label); |
629 | ||
630 | error = aa_path_name(old_path, path_flags(profile, old_path), | |
631 | old_buffer, &old_name, &info, | |
632 | profile->disconnected); | |
633 | if (error) | |
634 | goto audit; | |
635 | error = aa_path_name(new_path, path_flags(profile, new_path), | |
636 | new_buffer, &new_name, &info, | |
637 | profile->disconnected); | |
638 | if (error) | |
639 | goto audit; | |
640 | ||
641 | error = -EACCES; | |
642 | state = aa_dfa_match(profile->policy.dfa, | |
643 | profile->policy.start[AA_CLASS_MOUNT], | |
644 | new_name); | |
645 | state = aa_dfa_null_transition(profile->policy.dfa, state); | |
646 | state = aa_dfa_match(profile->policy.dfa, state, old_name); | |
647 | perms = compute_mnt_perms(profile->policy.dfa, state); | |
648 | ||
649 | if (AA_MAY_PIVOTROOT & perms.allow) | |
650 | error = 0; | |
651 | ||
652 | audit: | |
653 | error = audit_mount(profile, OP_PIVOTROOT, new_name, old_name, | |
654 | NULL, trans_name, 0, NULL, AA_MAY_PIVOTROOT, | |
655 | &perms, info, error); | |
656 | if (error) | |
657 | return ERR_PTR(error); | |
658 | ||
659 | return aa_get_newest_label(&profile->label); | |
660 | } | |
661 | ||
662 | int aa_pivotroot(struct aa_label *label, const struct path *old_path, | |
663 | const struct path *new_path) | |
664 | { | |
665 | struct aa_profile *profile; | |
666 | struct aa_label *target = NULL; | |
667 | char *old_buffer = NULL, *new_buffer = NULL, *info = NULL; | |
668 | int error; | |
669 | ||
670 | AA_BUG(!label); | |
671 | AA_BUG(!old_path); | |
672 | AA_BUG(!new_path); | |
673 | ||
674 | get_buffers(old_buffer, new_buffer); | |
675 | target = fn_label_build(label, profile, GFP_ATOMIC, | |
676 | build_pivotroot(profile, new_path, new_buffer, | |
677 | old_path, old_buffer)); | |
678 | if (!target) { | |
679 | info = "label build failed"; | |
680 | error = -ENOMEM; | |
681 | goto fail; | |
682 | } else if (!IS_ERR(target)) { | |
683 | error = aa_replace_current_label(target); | |
684 | if (error) { | |
685 | /* TODO: audit target */ | |
686 | aa_put_label(target); | |
687 | goto out; | |
688 | } | |
689 | } else | |
690 | /* already audited error */ | |
691 | error = PTR_ERR(target); | |
692 | out: | |
693 | put_buffers(old_buffer, new_buffer); | |
694 | ||
695 | return error; | |
696 | ||
697 | fail: | |
698 | /* TODO: add back in auditing of new_name and old_name */ | |
699 | error = fn_for_each(label, profile, | |
700 | audit_mount(profile, OP_PIVOTROOT, NULL /*new_name */, | |
701 | NULL /* old_name */, | |
702 | NULL, NULL, | |
703 | 0, NULL, AA_MAY_PIVOTROOT, &nullperms, info, | |
704 | error)); | |
705 | goto out; | |
706 | } |