Commit | Line | Data |
---|---|---|
74c3cbe3 AV |
1 | #include "audit.h" |
2 | #include <linux/inotify.h> | |
3 | #include <linux/namei.h> | |
4 | #include <linux/mount.h> | |
916d7576 | 5 | #include <linux/kthread.h> |
74c3cbe3 AV |
6 | |
7 | struct audit_tree; | |
8 | struct audit_chunk; | |
9 | ||
10 | struct audit_tree { | |
11 | atomic_t count; | |
12 | int goner; | |
13 | struct audit_chunk *root; | |
14 | struct list_head chunks; | |
15 | struct list_head rules; | |
16 | struct list_head list; | |
17 | struct list_head same_root; | |
18 | struct rcu_head head; | |
19 | char pathname[]; | |
20 | }; | |
21 | ||
22 | struct audit_chunk { | |
23 | struct list_head hash; | |
24 | struct inotify_watch watch; | |
25 | struct list_head trees; /* with root here */ | |
26 | int dead; | |
27 | int count; | |
8f7b0ba1 | 28 | atomic_long_t refs; |
74c3cbe3 AV |
29 | struct rcu_head head; |
30 | struct node { | |
31 | struct list_head list; | |
32 | struct audit_tree *owner; | |
33 | unsigned index; /* index; upper bit indicates 'will prune' */ | |
34 | } owners[]; | |
35 | }; | |
36 | ||
37 | static LIST_HEAD(tree_list); | |
38 | static LIST_HEAD(prune_list); | |
39 | ||
40 | /* | |
41 | * One struct chunk is attached to each inode of interest. | |
42 | * We replace struct chunk on tagging/untagging. | |
43 | * Rules have pointer to struct audit_tree. | |
44 | * Rules have struct list_head rlist forming a list of rules over | |
45 | * the same tree. | |
46 | * References to struct chunk are collected at audit_inode{,_child}() | |
47 | * time and used in AUDIT_TREE rule matching. | |
48 | * These references are dropped at the same time we are calling | |
49 | * audit_free_names(), etc. | |
50 | * | |
51 | * Cyclic lists galore: | |
52 | * tree.chunks anchors chunk.owners[].list hash_lock | |
53 | * tree.rules anchors rule.rlist audit_filter_mutex | |
54 | * chunk.trees anchors tree.same_root hash_lock | |
55 | * chunk.hash is a hash with middle bits of watch.inode as | |
56 | * a hash function. RCU, hash_lock | |
57 | * | |
58 | * tree is refcounted; one reference for "some rules on rules_list refer to | |
59 | * it", one for each chunk with pointer to it. | |
60 | * | |
8f7b0ba1 AV |
61 | * chunk is refcounted by embedded inotify_watch + .refs (non-zero refcount |
62 | * of watch contributes 1 to .refs). | |
74c3cbe3 AV |
63 | * |
64 | * node.index allows to get from node.list to containing chunk. | |
65 | * MSB of that sucker is stolen to mark taggings that we might have to | |
66 | * revert - several operations have very unpleasant cleanup logics and | |
67 | * that makes a difference. Some. | |
68 | */ | |
69 | ||
70 | static struct inotify_handle *rtree_ih; | |
71 | ||
72 | static struct audit_tree *alloc_tree(const char *s) | |
73 | { | |
74 | struct audit_tree *tree; | |
75 | ||
76 | tree = kmalloc(sizeof(struct audit_tree) + strlen(s) + 1, GFP_KERNEL); | |
77 | if (tree) { | |
78 | atomic_set(&tree->count, 1); | |
79 | tree->goner = 0; | |
80 | INIT_LIST_HEAD(&tree->chunks); | |
81 | INIT_LIST_HEAD(&tree->rules); | |
82 | INIT_LIST_HEAD(&tree->list); | |
83 | INIT_LIST_HEAD(&tree->same_root); | |
84 | tree->root = NULL; | |
85 | strcpy(tree->pathname, s); | |
86 | } | |
87 | return tree; | |
88 | } | |
89 | ||
90 | static inline void get_tree(struct audit_tree *tree) | |
91 | { | |
92 | atomic_inc(&tree->count); | |
93 | } | |
94 | ||
95 | static void __put_tree(struct rcu_head *rcu) | |
96 | { | |
97 | struct audit_tree *tree = container_of(rcu, struct audit_tree, head); | |
98 | kfree(tree); | |
99 | } | |
100 | ||
101 | static inline void put_tree(struct audit_tree *tree) | |
102 | { | |
103 | if (atomic_dec_and_test(&tree->count)) | |
104 | call_rcu(&tree->head, __put_tree); | |
105 | } | |
106 | ||
107 | /* to avoid bringing the entire thing in audit.h */ | |
108 | const char *audit_tree_path(struct audit_tree *tree) | |
109 | { | |
110 | return tree->pathname; | |
111 | } | |
112 | ||
113 | static struct audit_chunk *alloc_chunk(int count) | |
114 | { | |
115 | struct audit_chunk *chunk; | |
116 | size_t size; | |
117 | int i; | |
118 | ||
119 | size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node); | |
120 | chunk = kzalloc(size, GFP_KERNEL); | |
121 | if (!chunk) | |
122 | return NULL; | |
123 | ||
124 | INIT_LIST_HEAD(&chunk->hash); | |
125 | INIT_LIST_HEAD(&chunk->trees); | |
126 | chunk->count = count; | |
8f7b0ba1 | 127 | atomic_long_set(&chunk->refs, 1); |
74c3cbe3 AV |
128 | for (i = 0; i < count; i++) { |
129 | INIT_LIST_HEAD(&chunk->owners[i].list); | |
130 | chunk->owners[i].index = i; | |
131 | } | |
132 | inotify_init_watch(&chunk->watch); | |
133 | return chunk; | |
134 | } | |
135 | ||
8f7b0ba1 | 136 | static void free_chunk(struct audit_chunk *chunk) |
74c3cbe3 | 137 | { |
74c3cbe3 AV |
138 | int i; |
139 | ||
140 | for (i = 0; i < chunk->count; i++) { | |
141 | if (chunk->owners[i].owner) | |
142 | put_tree(chunk->owners[i].owner); | |
143 | } | |
144 | kfree(chunk); | |
145 | } | |
146 | ||
8f7b0ba1 | 147 | void audit_put_chunk(struct audit_chunk *chunk) |
74c3cbe3 | 148 | { |
8f7b0ba1 AV |
149 | if (atomic_long_dec_and_test(&chunk->refs)) |
150 | free_chunk(chunk); | |
74c3cbe3 AV |
151 | } |
152 | ||
8f7b0ba1 | 153 | static void __put_chunk(struct rcu_head *rcu) |
74c3cbe3 | 154 | { |
8f7b0ba1 AV |
155 | struct audit_chunk *chunk = container_of(rcu, struct audit_chunk, head); |
156 | audit_put_chunk(chunk); | |
74c3cbe3 AV |
157 | } |
158 | ||
159 | enum {HASH_SIZE = 128}; | |
160 | static struct list_head chunk_hash_heads[HASH_SIZE]; | |
161 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock); | |
162 | ||
163 | static inline struct list_head *chunk_hash(const struct inode *inode) | |
164 | { | |
165 | unsigned long n = (unsigned long)inode / L1_CACHE_BYTES; | |
166 | return chunk_hash_heads + n % HASH_SIZE; | |
167 | } | |
168 | ||
169 | /* hash_lock is held by caller */ | |
170 | static void insert_hash(struct audit_chunk *chunk) | |
171 | { | |
172 | struct list_head *list = chunk_hash(chunk->watch.inode); | |
173 | list_add_rcu(&chunk->hash, list); | |
174 | } | |
175 | ||
176 | /* called under rcu_read_lock */ | |
177 | struct audit_chunk *audit_tree_lookup(const struct inode *inode) | |
178 | { | |
179 | struct list_head *list = chunk_hash(inode); | |
6793a051 | 180 | struct audit_chunk *p; |
74c3cbe3 | 181 | |
6793a051 | 182 | list_for_each_entry_rcu(p, list, hash) { |
74c3cbe3 | 183 | if (p->watch.inode == inode) { |
8f7b0ba1 | 184 | atomic_long_inc(&p->refs); |
74c3cbe3 AV |
185 | return p; |
186 | } | |
187 | } | |
188 | return NULL; | |
189 | } | |
190 | ||
191 | int audit_tree_match(struct audit_chunk *chunk, struct audit_tree *tree) | |
192 | { | |
193 | int n; | |
194 | for (n = 0; n < chunk->count; n++) | |
195 | if (chunk->owners[n].owner == tree) | |
196 | return 1; | |
197 | return 0; | |
198 | } | |
199 | ||
200 | /* tagging and untagging inodes with trees */ | |
201 | ||
8f7b0ba1 AV |
202 | static struct audit_chunk *find_chunk(struct node *p) |
203 | { | |
204 | int index = p->index & ~(1U<<31); | |
205 | p -= index; | |
206 | return container_of(p, struct audit_chunk, owners[0]); | |
207 | } | |
208 | ||
209 | static void untag_chunk(struct node *p) | |
74c3cbe3 | 210 | { |
8f7b0ba1 | 211 | struct audit_chunk *chunk = find_chunk(p); |
74c3cbe3 AV |
212 | struct audit_chunk *new; |
213 | struct audit_tree *owner; | |
214 | int size = chunk->count - 1; | |
215 | int i, j; | |
216 | ||
8f7b0ba1 AV |
217 | if (!pin_inotify_watch(&chunk->watch)) { |
218 | /* | |
219 | * Filesystem is shutting down; all watches are getting | |
220 | * evicted, just take it off the node list for this | |
221 | * tree and let the eviction logics take care of the | |
222 | * rest. | |
223 | */ | |
224 | owner = p->owner; | |
225 | if (owner->root == chunk) { | |
226 | list_del_init(&owner->same_root); | |
227 | owner->root = NULL; | |
228 | } | |
229 | list_del_init(&p->list); | |
230 | p->owner = NULL; | |
231 | put_tree(owner); | |
232 | return; | |
233 | } | |
234 | ||
235 | spin_unlock(&hash_lock); | |
236 | ||
237 | /* | |
238 | * pin_inotify_watch() succeeded, so the watch won't go away | |
239 | * from under us. | |
240 | */ | |
74c3cbe3 AV |
241 | mutex_lock(&chunk->watch.inode->inotify_mutex); |
242 | if (chunk->dead) { | |
243 | mutex_unlock(&chunk->watch.inode->inotify_mutex); | |
8f7b0ba1 | 244 | goto out; |
74c3cbe3 AV |
245 | } |
246 | ||
247 | owner = p->owner; | |
248 | ||
249 | if (!size) { | |
250 | chunk->dead = 1; | |
251 | spin_lock(&hash_lock); | |
252 | list_del_init(&chunk->trees); | |
253 | if (owner->root == chunk) | |
254 | owner->root = NULL; | |
255 | list_del_init(&p->list); | |
256 | list_del_rcu(&chunk->hash); | |
257 | spin_unlock(&hash_lock); | |
258 | inotify_evict_watch(&chunk->watch); | |
259 | mutex_unlock(&chunk->watch.inode->inotify_mutex); | |
260 | put_inotify_watch(&chunk->watch); | |
8f7b0ba1 | 261 | goto out; |
74c3cbe3 AV |
262 | } |
263 | ||
264 | new = alloc_chunk(size); | |
265 | if (!new) | |
266 | goto Fallback; | |
267 | if (inotify_clone_watch(&chunk->watch, &new->watch) < 0) { | |
268 | free_chunk(new); | |
269 | goto Fallback; | |
270 | } | |
271 | ||
272 | chunk->dead = 1; | |
273 | spin_lock(&hash_lock); | |
274 | list_replace_init(&chunk->trees, &new->trees); | |
275 | if (owner->root == chunk) { | |
276 | list_del_init(&owner->same_root); | |
277 | owner->root = NULL; | |
278 | } | |
279 | ||
280 | for (i = j = 0; i < size; i++, j++) { | |
281 | struct audit_tree *s; | |
282 | if (&chunk->owners[j] == p) { | |
283 | list_del_init(&p->list); | |
284 | i--; | |
285 | continue; | |
286 | } | |
287 | s = chunk->owners[j].owner; | |
288 | new->owners[i].owner = s; | |
289 | new->owners[i].index = chunk->owners[j].index - j + i; | |
290 | if (!s) /* result of earlier fallback */ | |
291 | continue; | |
292 | get_tree(s); | |
293 | list_replace_init(&chunk->owners[i].list, &new->owners[j].list); | |
294 | } | |
295 | ||
296 | list_replace_rcu(&chunk->hash, &new->hash); | |
297 | list_for_each_entry(owner, &new->trees, same_root) | |
298 | owner->root = new; | |
299 | spin_unlock(&hash_lock); | |
300 | inotify_evict_watch(&chunk->watch); | |
301 | mutex_unlock(&chunk->watch.inode->inotify_mutex); | |
302 | put_inotify_watch(&chunk->watch); | |
8f7b0ba1 | 303 | goto out; |
74c3cbe3 AV |
304 | |
305 | Fallback: | |
306 | // do the best we can | |
307 | spin_lock(&hash_lock); | |
308 | if (owner->root == chunk) { | |
309 | list_del_init(&owner->same_root); | |
310 | owner->root = NULL; | |
311 | } | |
312 | list_del_init(&p->list); | |
313 | p->owner = NULL; | |
314 | put_tree(owner); | |
315 | spin_unlock(&hash_lock); | |
316 | mutex_unlock(&chunk->watch.inode->inotify_mutex); | |
8f7b0ba1 AV |
317 | out: |
318 | unpin_inotify_watch(&chunk->watch); | |
319 | spin_lock(&hash_lock); | |
74c3cbe3 AV |
320 | } |
321 | ||
322 | static int create_chunk(struct inode *inode, struct audit_tree *tree) | |
323 | { | |
324 | struct audit_chunk *chunk = alloc_chunk(1); | |
325 | if (!chunk) | |
326 | return -ENOMEM; | |
327 | ||
328 | if (inotify_add_watch(rtree_ih, &chunk->watch, inode, IN_IGNORED | IN_DELETE_SELF) < 0) { | |
329 | free_chunk(chunk); | |
330 | return -ENOSPC; | |
331 | } | |
332 | ||
333 | mutex_lock(&inode->inotify_mutex); | |
334 | spin_lock(&hash_lock); | |
335 | if (tree->goner) { | |
336 | spin_unlock(&hash_lock); | |
337 | chunk->dead = 1; | |
338 | inotify_evict_watch(&chunk->watch); | |
339 | mutex_unlock(&inode->inotify_mutex); | |
340 | put_inotify_watch(&chunk->watch); | |
341 | return 0; | |
342 | } | |
343 | chunk->owners[0].index = (1U << 31); | |
344 | chunk->owners[0].owner = tree; | |
345 | get_tree(tree); | |
346 | list_add(&chunk->owners[0].list, &tree->chunks); | |
347 | if (!tree->root) { | |
348 | tree->root = chunk; | |
349 | list_add(&tree->same_root, &chunk->trees); | |
350 | } | |
351 | insert_hash(chunk); | |
352 | spin_unlock(&hash_lock); | |
353 | mutex_unlock(&inode->inotify_mutex); | |
354 | return 0; | |
355 | } | |
356 | ||
357 | /* the first tagged inode becomes root of tree */ | |
358 | static int tag_chunk(struct inode *inode, struct audit_tree *tree) | |
359 | { | |
360 | struct inotify_watch *watch; | |
361 | struct audit_tree *owner; | |
362 | struct audit_chunk *chunk, *old; | |
363 | struct node *p; | |
364 | int n; | |
365 | ||
366 | if (inotify_find_watch(rtree_ih, inode, &watch) < 0) | |
367 | return create_chunk(inode, tree); | |
368 | ||
369 | old = container_of(watch, struct audit_chunk, watch); | |
370 | ||
371 | /* are we already there? */ | |
372 | spin_lock(&hash_lock); | |
373 | for (n = 0; n < old->count; n++) { | |
374 | if (old->owners[n].owner == tree) { | |
375 | spin_unlock(&hash_lock); | |
376 | put_inotify_watch(watch); | |
377 | return 0; | |
378 | } | |
379 | } | |
380 | spin_unlock(&hash_lock); | |
381 | ||
382 | chunk = alloc_chunk(old->count + 1); | |
383 | if (!chunk) | |
384 | return -ENOMEM; | |
385 | ||
386 | mutex_lock(&inode->inotify_mutex); | |
387 | if (inotify_clone_watch(&old->watch, &chunk->watch) < 0) { | |
388 | mutex_unlock(&inode->inotify_mutex); | |
318b6d3d | 389 | put_inotify_watch(&old->watch); |
74c3cbe3 AV |
390 | free_chunk(chunk); |
391 | return -ENOSPC; | |
392 | } | |
393 | spin_lock(&hash_lock); | |
394 | if (tree->goner) { | |
395 | spin_unlock(&hash_lock); | |
396 | chunk->dead = 1; | |
397 | inotify_evict_watch(&chunk->watch); | |
398 | mutex_unlock(&inode->inotify_mutex); | |
318b6d3d | 399 | put_inotify_watch(&old->watch); |
74c3cbe3 AV |
400 | put_inotify_watch(&chunk->watch); |
401 | return 0; | |
402 | } | |
403 | list_replace_init(&old->trees, &chunk->trees); | |
404 | for (n = 0, p = chunk->owners; n < old->count; n++, p++) { | |
405 | struct audit_tree *s = old->owners[n].owner; | |
406 | p->owner = s; | |
407 | p->index = old->owners[n].index; | |
408 | if (!s) /* result of fallback in untag */ | |
409 | continue; | |
410 | get_tree(s); | |
411 | list_replace_init(&old->owners[n].list, &p->list); | |
412 | } | |
413 | p->index = (chunk->count - 1) | (1U<<31); | |
414 | p->owner = tree; | |
415 | get_tree(tree); | |
416 | list_add(&p->list, &tree->chunks); | |
417 | list_replace_rcu(&old->hash, &chunk->hash); | |
418 | list_for_each_entry(owner, &chunk->trees, same_root) | |
419 | owner->root = chunk; | |
420 | old->dead = 1; | |
421 | if (!tree->root) { | |
422 | tree->root = chunk; | |
423 | list_add(&tree->same_root, &chunk->trees); | |
424 | } | |
425 | spin_unlock(&hash_lock); | |
426 | inotify_evict_watch(&old->watch); | |
427 | mutex_unlock(&inode->inotify_mutex); | |
428 | put_inotify_watch(&old->watch); | |
429 | return 0; | |
430 | } | |
431 | ||
74c3cbe3 AV |
432 | static void kill_rules(struct audit_tree *tree) |
433 | { | |
434 | struct audit_krule *rule, *next; | |
435 | struct audit_entry *entry; | |
436 | struct audit_buffer *ab; | |
437 | ||
438 | list_for_each_entry_safe(rule, next, &tree->rules, rlist) { | |
439 | entry = container_of(rule, struct audit_entry, rule); | |
440 | ||
441 | list_del_init(&rule->rlist); | |
442 | if (rule->tree) { | |
443 | /* not a half-baked one */ | |
444 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); | |
9d960985 EP |
445 | audit_log_format(ab, "op="); |
446 | audit_log_string(ab, "remove rule"); | |
447 | audit_log_format(ab, " dir="); | |
74c3cbe3 | 448 | audit_log_untrustedstring(ab, rule->tree->pathname); |
9d960985 | 449 | audit_log_key(ab, rule->filterkey); |
74c3cbe3 AV |
450 | audit_log_format(ab, " list=%d res=1", rule->listnr); |
451 | audit_log_end(ab); | |
452 | rule->tree = NULL; | |
453 | list_del_rcu(&entry->list); | |
e45aa212 | 454 | list_del(&entry->rule.list); |
74c3cbe3 AV |
455 | call_rcu(&entry->rcu, audit_free_rule_rcu); |
456 | } | |
457 | } | |
458 | } | |
459 | ||
460 | /* | |
461 | * finish killing struct audit_tree | |
462 | */ | |
463 | static void prune_one(struct audit_tree *victim) | |
464 | { | |
465 | spin_lock(&hash_lock); | |
466 | while (!list_empty(&victim->chunks)) { | |
467 | struct node *p; | |
74c3cbe3 AV |
468 | |
469 | p = list_entry(victim->chunks.next, struct node, list); | |
74c3cbe3 | 470 | |
8f7b0ba1 | 471 | untag_chunk(p); |
74c3cbe3 AV |
472 | } |
473 | spin_unlock(&hash_lock); | |
474 | put_tree(victim); | |
475 | } | |
476 | ||
477 | /* trim the uncommitted chunks from tree */ | |
478 | ||
479 | static void trim_marked(struct audit_tree *tree) | |
480 | { | |
481 | struct list_head *p, *q; | |
482 | spin_lock(&hash_lock); | |
483 | if (tree->goner) { | |
484 | spin_unlock(&hash_lock); | |
485 | return; | |
486 | } | |
487 | /* reorder */ | |
488 | for (p = tree->chunks.next; p != &tree->chunks; p = q) { | |
489 | struct node *node = list_entry(p, struct node, list); | |
490 | q = p->next; | |
491 | if (node->index & (1U<<31)) { | |
492 | list_del_init(p); | |
493 | list_add(p, &tree->chunks); | |
494 | } | |
495 | } | |
496 | ||
497 | while (!list_empty(&tree->chunks)) { | |
498 | struct node *node; | |
74c3cbe3 AV |
499 | |
500 | node = list_entry(tree->chunks.next, struct node, list); | |
501 | ||
502 | /* have we run out of marked? */ | |
503 | if (!(node->index & (1U<<31))) | |
504 | break; | |
505 | ||
8f7b0ba1 | 506 | untag_chunk(node); |
74c3cbe3 AV |
507 | } |
508 | if (!tree->root && !tree->goner) { | |
509 | tree->goner = 1; | |
510 | spin_unlock(&hash_lock); | |
511 | mutex_lock(&audit_filter_mutex); | |
512 | kill_rules(tree); | |
513 | list_del_init(&tree->list); | |
514 | mutex_unlock(&audit_filter_mutex); | |
515 | prune_one(tree); | |
516 | } else { | |
517 | spin_unlock(&hash_lock); | |
518 | } | |
519 | } | |
520 | ||
916d7576 AV |
521 | static void audit_schedule_prune(void); |
522 | ||
74c3cbe3 AV |
523 | /* called with audit_filter_mutex */ |
524 | int audit_remove_tree_rule(struct audit_krule *rule) | |
525 | { | |
526 | struct audit_tree *tree; | |
527 | tree = rule->tree; | |
528 | if (tree) { | |
529 | spin_lock(&hash_lock); | |
530 | list_del_init(&rule->rlist); | |
531 | if (list_empty(&tree->rules) && !tree->goner) { | |
532 | tree->root = NULL; | |
533 | list_del_init(&tree->same_root); | |
534 | tree->goner = 1; | |
535 | list_move(&tree->list, &prune_list); | |
536 | rule->tree = NULL; | |
537 | spin_unlock(&hash_lock); | |
538 | audit_schedule_prune(); | |
539 | return 1; | |
540 | } | |
541 | rule->tree = NULL; | |
542 | spin_unlock(&hash_lock); | |
543 | return 1; | |
544 | } | |
545 | return 0; | |
546 | } | |
547 | ||
548 | void audit_trim_trees(void) | |
549 | { | |
550 | struct list_head cursor; | |
551 | ||
552 | mutex_lock(&audit_filter_mutex); | |
553 | list_add(&cursor, &tree_list); | |
554 | while (cursor.next != &tree_list) { | |
555 | struct audit_tree *tree; | |
98bc993f | 556 | struct path path; |
74c3cbe3 AV |
557 | struct vfsmount *root_mnt; |
558 | struct node *node; | |
559 | struct list_head list; | |
560 | int err; | |
561 | ||
562 | tree = container_of(cursor.next, struct audit_tree, list); | |
563 | get_tree(tree); | |
564 | list_del(&cursor); | |
565 | list_add(&cursor, &tree->list); | |
566 | mutex_unlock(&audit_filter_mutex); | |
567 | ||
98bc993f | 568 | err = kern_path(tree->pathname, 0, &path); |
74c3cbe3 AV |
569 | if (err) |
570 | goto skip_it; | |
571 | ||
589ff870 | 572 | root_mnt = collect_mounts(&path); |
98bc993f | 573 | path_put(&path); |
74c3cbe3 AV |
574 | if (!root_mnt) |
575 | goto skip_it; | |
576 | ||
577 | list_add_tail(&list, &root_mnt->mnt_list); | |
578 | spin_lock(&hash_lock); | |
579 | list_for_each_entry(node, &tree->chunks, list) { | |
580 | struct audit_chunk *chunk = find_chunk(node); | |
581 | struct inode *inode = chunk->watch.inode; | |
582 | struct vfsmount *mnt; | |
583 | node->index |= 1U<<31; | |
584 | list_for_each_entry(mnt, &list, mnt_list) { | |
585 | if (mnt->mnt_root->d_inode == inode) { | |
586 | node->index &= ~(1U<<31); | |
587 | break; | |
588 | } | |
589 | } | |
590 | } | |
591 | spin_unlock(&hash_lock); | |
592 | trim_marked(tree); | |
593 | put_tree(tree); | |
594 | list_del_init(&list); | |
595 | drop_collected_mounts(root_mnt); | |
596 | skip_it: | |
597 | mutex_lock(&audit_filter_mutex); | |
598 | } | |
599 | list_del(&cursor); | |
600 | mutex_unlock(&audit_filter_mutex); | |
601 | } | |
602 | ||
603 | static int is_under(struct vfsmount *mnt, struct dentry *dentry, | |
98bc993f | 604 | struct path *path) |
74c3cbe3 | 605 | { |
98bc993f | 606 | if (mnt != path->mnt) { |
74c3cbe3 AV |
607 | for (;;) { |
608 | if (mnt->mnt_parent == mnt) | |
609 | return 0; | |
98bc993f | 610 | if (mnt->mnt_parent == path->mnt) |
74c3cbe3 AV |
611 | break; |
612 | mnt = mnt->mnt_parent; | |
613 | } | |
614 | dentry = mnt->mnt_mountpoint; | |
615 | } | |
98bc993f | 616 | return is_subdir(dentry, path->dentry); |
74c3cbe3 AV |
617 | } |
618 | ||
619 | int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op) | |
620 | { | |
621 | ||
622 | if (pathname[0] != '/' || | |
623 | rule->listnr != AUDIT_FILTER_EXIT || | |
5af75d8d | 624 | op != Audit_equal || |
74c3cbe3 AV |
625 | rule->inode_f || rule->watch || rule->tree) |
626 | return -EINVAL; | |
627 | rule->tree = alloc_tree(pathname); | |
628 | if (!rule->tree) | |
629 | return -ENOMEM; | |
630 | return 0; | |
631 | } | |
632 | ||
633 | void audit_put_tree(struct audit_tree *tree) | |
634 | { | |
635 | put_tree(tree); | |
636 | } | |
637 | ||
638 | /* called with audit_filter_mutex */ | |
639 | int audit_add_tree_rule(struct audit_krule *rule) | |
640 | { | |
641 | struct audit_tree *seed = rule->tree, *tree; | |
98bc993f | 642 | struct path path; |
74c3cbe3 AV |
643 | struct vfsmount *mnt, *p; |
644 | struct list_head list; | |
645 | int err; | |
646 | ||
647 | list_for_each_entry(tree, &tree_list, list) { | |
648 | if (!strcmp(seed->pathname, tree->pathname)) { | |
649 | put_tree(seed); | |
650 | rule->tree = tree; | |
651 | list_add(&rule->rlist, &tree->rules); | |
652 | return 0; | |
653 | } | |
654 | } | |
655 | tree = seed; | |
656 | list_add(&tree->list, &tree_list); | |
657 | list_add(&rule->rlist, &tree->rules); | |
658 | /* do not set rule->tree yet */ | |
659 | mutex_unlock(&audit_filter_mutex); | |
660 | ||
98bc993f | 661 | err = kern_path(tree->pathname, 0, &path); |
74c3cbe3 AV |
662 | if (err) |
663 | goto Err; | |
589ff870 | 664 | mnt = collect_mounts(&path); |
98bc993f | 665 | path_put(&path); |
74c3cbe3 AV |
666 | if (!mnt) { |
667 | err = -ENOMEM; | |
668 | goto Err; | |
669 | } | |
670 | list_add_tail(&list, &mnt->mnt_list); | |
671 | ||
672 | get_tree(tree); | |
673 | list_for_each_entry(p, &list, mnt_list) { | |
674 | err = tag_chunk(p->mnt_root->d_inode, tree); | |
675 | if (err) | |
676 | break; | |
677 | } | |
678 | ||
679 | list_del(&list); | |
680 | drop_collected_mounts(mnt); | |
681 | ||
682 | if (!err) { | |
683 | struct node *node; | |
684 | spin_lock(&hash_lock); | |
685 | list_for_each_entry(node, &tree->chunks, list) | |
686 | node->index &= ~(1U<<31); | |
687 | spin_unlock(&hash_lock); | |
688 | } else { | |
689 | trim_marked(tree); | |
690 | goto Err; | |
691 | } | |
692 | ||
693 | mutex_lock(&audit_filter_mutex); | |
694 | if (list_empty(&rule->rlist)) { | |
695 | put_tree(tree); | |
696 | return -ENOENT; | |
697 | } | |
698 | rule->tree = tree; | |
699 | put_tree(tree); | |
700 | ||
701 | return 0; | |
702 | Err: | |
703 | mutex_lock(&audit_filter_mutex); | |
704 | list_del_init(&tree->list); | |
705 | list_del_init(&tree->rules); | |
706 | put_tree(tree); | |
707 | return err; | |
708 | } | |
709 | ||
710 | int audit_tag_tree(char *old, char *new) | |
711 | { | |
712 | struct list_head cursor, barrier; | |
713 | int failed = 0; | |
98bc993f | 714 | struct path path; |
74c3cbe3 AV |
715 | struct vfsmount *tagged; |
716 | struct list_head list; | |
717 | struct vfsmount *mnt; | |
718 | struct dentry *dentry; | |
719 | int err; | |
720 | ||
98bc993f | 721 | err = kern_path(new, 0, &path); |
74c3cbe3 AV |
722 | if (err) |
723 | return err; | |
589ff870 | 724 | tagged = collect_mounts(&path); |
98bc993f | 725 | path_put(&path); |
74c3cbe3 AV |
726 | if (!tagged) |
727 | return -ENOMEM; | |
728 | ||
98bc993f | 729 | err = kern_path(old, 0, &path); |
74c3cbe3 AV |
730 | if (err) { |
731 | drop_collected_mounts(tagged); | |
732 | return err; | |
733 | } | |
98bc993f AV |
734 | mnt = mntget(path.mnt); |
735 | dentry = dget(path.dentry); | |
736 | path_put(&path); | |
74c3cbe3 | 737 | |
74c3cbe3 AV |
738 | list_add_tail(&list, &tagged->mnt_list); |
739 | ||
740 | mutex_lock(&audit_filter_mutex); | |
741 | list_add(&barrier, &tree_list); | |
742 | list_add(&cursor, &barrier); | |
743 | ||
744 | while (cursor.next != &tree_list) { | |
745 | struct audit_tree *tree; | |
746 | struct vfsmount *p; | |
747 | ||
748 | tree = container_of(cursor.next, struct audit_tree, list); | |
749 | get_tree(tree); | |
750 | list_del(&cursor); | |
751 | list_add(&cursor, &tree->list); | |
752 | mutex_unlock(&audit_filter_mutex); | |
753 | ||
98bc993f | 754 | err = kern_path(tree->pathname, 0, &path); |
74c3cbe3 AV |
755 | if (err) { |
756 | put_tree(tree); | |
757 | mutex_lock(&audit_filter_mutex); | |
758 | continue; | |
759 | } | |
760 | ||
761 | spin_lock(&vfsmount_lock); | |
98bc993f | 762 | if (!is_under(mnt, dentry, &path)) { |
74c3cbe3 | 763 | spin_unlock(&vfsmount_lock); |
98bc993f | 764 | path_put(&path); |
74c3cbe3 AV |
765 | put_tree(tree); |
766 | mutex_lock(&audit_filter_mutex); | |
767 | continue; | |
768 | } | |
769 | spin_unlock(&vfsmount_lock); | |
98bc993f | 770 | path_put(&path); |
74c3cbe3 AV |
771 | |
772 | list_for_each_entry(p, &list, mnt_list) { | |
773 | failed = tag_chunk(p->mnt_root->d_inode, tree); | |
774 | if (failed) | |
775 | break; | |
776 | } | |
777 | ||
778 | if (failed) { | |
779 | put_tree(tree); | |
780 | mutex_lock(&audit_filter_mutex); | |
781 | break; | |
782 | } | |
783 | ||
784 | mutex_lock(&audit_filter_mutex); | |
785 | spin_lock(&hash_lock); | |
786 | if (!tree->goner) { | |
787 | list_del(&tree->list); | |
788 | list_add(&tree->list, &tree_list); | |
789 | } | |
790 | spin_unlock(&hash_lock); | |
791 | put_tree(tree); | |
792 | } | |
793 | ||
794 | while (barrier.prev != &tree_list) { | |
795 | struct audit_tree *tree; | |
796 | ||
797 | tree = container_of(barrier.prev, struct audit_tree, list); | |
798 | get_tree(tree); | |
799 | list_del(&tree->list); | |
800 | list_add(&tree->list, &barrier); | |
801 | mutex_unlock(&audit_filter_mutex); | |
802 | ||
803 | if (!failed) { | |
804 | struct node *node; | |
805 | spin_lock(&hash_lock); | |
806 | list_for_each_entry(node, &tree->chunks, list) | |
807 | node->index &= ~(1U<<31); | |
808 | spin_unlock(&hash_lock); | |
809 | } else { | |
810 | trim_marked(tree); | |
811 | } | |
812 | ||
813 | put_tree(tree); | |
814 | mutex_lock(&audit_filter_mutex); | |
815 | } | |
816 | list_del(&barrier); | |
817 | list_del(&cursor); | |
818 | list_del(&list); | |
819 | mutex_unlock(&audit_filter_mutex); | |
820 | dput(dentry); | |
821 | mntput(mnt); | |
822 | drop_collected_mounts(tagged); | |
823 | return failed; | |
824 | } | |
825 | ||
826 | /* | |
827 | * That gets run when evict_chunk() ends up needing to kill audit_tree. | |
916d7576 | 828 | * Runs from a separate thread. |
74c3cbe3 | 829 | */ |
916d7576 | 830 | static int prune_tree_thread(void *unused) |
74c3cbe3 | 831 | { |
916d7576 | 832 | mutex_lock(&audit_cmd_mutex); |
74c3cbe3 AV |
833 | mutex_lock(&audit_filter_mutex); |
834 | ||
835 | while (!list_empty(&prune_list)) { | |
836 | struct audit_tree *victim; | |
837 | ||
838 | victim = list_entry(prune_list.next, struct audit_tree, list); | |
839 | list_del_init(&victim->list); | |
840 | ||
841 | mutex_unlock(&audit_filter_mutex); | |
842 | ||
843 | prune_one(victim); | |
844 | ||
845 | mutex_lock(&audit_filter_mutex); | |
846 | } | |
847 | ||
848 | mutex_unlock(&audit_filter_mutex); | |
916d7576 AV |
849 | mutex_unlock(&audit_cmd_mutex); |
850 | return 0; | |
851 | } | |
852 | ||
853 | static void audit_schedule_prune(void) | |
854 | { | |
855 | kthread_run(prune_tree_thread, NULL, "audit_prune_tree"); | |
856 | } | |
857 | ||
858 | /* | |
859 | * ... and that one is done if evict_chunk() decides to delay until the end | |
860 | * of syscall. Runs synchronously. | |
861 | */ | |
862 | void audit_kill_trees(struct list_head *list) | |
863 | { | |
864 | mutex_lock(&audit_cmd_mutex); | |
865 | mutex_lock(&audit_filter_mutex); | |
866 | ||
867 | while (!list_empty(list)) { | |
868 | struct audit_tree *victim; | |
869 | ||
870 | victim = list_entry(list->next, struct audit_tree, list); | |
871 | kill_rules(victim); | |
872 | list_del_init(&victim->list); | |
873 | ||
874 | mutex_unlock(&audit_filter_mutex); | |
875 | ||
876 | prune_one(victim); | |
877 | ||
878 | mutex_lock(&audit_filter_mutex); | |
879 | } | |
880 | ||
881 | mutex_unlock(&audit_filter_mutex); | |
882 | mutex_unlock(&audit_cmd_mutex); | |
74c3cbe3 AV |
883 | } |
884 | ||
885 | /* | |
886 | * Here comes the stuff asynchronous to auditctl operations | |
887 | */ | |
888 | ||
889 | /* inode->inotify_mutex is locked */ | |
890 | static void evict_chunk(struct audit_chunk *chunk) | |
891 | { | |
892 | struct audit_tree *owner; | |
916d7576 AV |
893 | struct list_head *postponed = audit_killed_trees(); |
894 | int need_prune = 0; | |
74c3cbe3 AV |
895 | int n; |
896 | ||
897 | if (chunk->dead) | |
898 | return; | |
899 | ||
900 | chunk->dead = 1; | |
901 | mutex_lock(&audit_filter_mutex); | |
902 | spin_lock(&hash_lock); | |
903 | while (!list_empty(&chunk->trees)) { | |
904 | owner = list_entry(chunk->trees.next, | |
905 | struct audit_tree, same_root); | |
906 | owner->goner = 1; | |
907 | owner->root = NULL; | |
908 | list_del_init(&owner->same_root); | |
909 | spin_unlock(&hash_lock); | |
916d7576 AV |
910 | if (!postponed) { |
911 | kill_rules(owner); | |
912 | list_move(&owner->list, &prune_list); | |
913 | need_prune = 1; | |
914 | } else { | |
915 | list_move(&owner->list, postponed); | |
916 | } | |
74c3cbe3 AV |
917 | spin_lock(&hash_lock); |
918 | } | |
919 | list_del_rcu(&chunk->hash); | |
920 | for (n = 0; n < chunk->count; n++) | |
921 | list_del_init(&chunk->owners[n].list); | |
922 | spin_unlock(&hash_lock); | |
916d7576 AV |
923 | if (need_prune) |
924 | audit_schedule_prune(); | |
74c3cbe3 AV |
925 | mutex_unlock(&audit_filter_mutex); |
926 | } | |
927 | ||
928 | static void handle_event(struct inotify_watch *watch, u32 wd, u32 mask, | |
929 | u32 cookie, const char *dname, struct inode *inode) | |
930 | { | |
931 | struct audit_chunk *chunk = container_of(watch, struct audit_chunk, watch); | |
932 | ||
933 | if (mask & IN_IGNORED) { | |
934 | evict_chunk(chunk); | |
935 | put_inotify_watch(watch); | |
936 | } | |
937 | } | |
938 | ||
939 | static void destroy_watch(struct inotify_watch *watch) | |
940 | { | |
941 | struct audit_chunk *chunk = container_of(watch, struct audit_chunk, watch); | |
8f7b0ba1 | 942 | call_rcu(&chunk->head, __put_chunk); |
74c3cbe3 AV |
943 | } |
944 | ||
945 | static const struct inotify_operations rtree_inotify_ops = { | |
946 | .handle_event = handle_event, | |
947 | .destroy_watch = destroy_watch, | |
948 | }; | |
949 | ||
950 | static int __init audit_tree_init(void) | |
951 | { | |
952 | int i; | |
953 | ||
954 | rtree_ih = inotify_init(&rtree_inotify_ops); | |
955 | if (IS_ERR(rtree_ih)) | |
956 | audit_panic("cannot initialize inotify handle for rectree watches"); | |
957 | ||
958 | for (i = 0; i < HASH_SIZE; i++) | |
959 | INIT_LIST_HEAD(&chunk_hash_heads[i]); | |
960 | ||
961 | return 0; | |
962 | } | |
963 | __initcall(audit_tree_init); |