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> |
5a0e3ad6 | 6 | #include <linux/slab.h> |
74c3cbe3 AV |
7 | |
8 | struct audit_tree; | |
9 | struct audit_chunk; | |
10 | ||
11 | struct audit_tree { | |
12 | atomic_t count; | |
13 | int goner; | |
14 | struct audit_chunk *root; | |
15 | struct list_head chunks; | |
16 | struct list_head rules; | |
17 | struct list_head list; | |
18 | struct list_head same_root; | |
19 | struct rcu_head head; | |
20 | char pathname[]; | |
21 | }; | |
22 | ||
23 | struct audit_chunk { | |
24 | struct list_head hash; | |
25 | struct inotify_watch watch; | |
26 | struct list_head trees; /* with root here */ | |
27 | int dead; | |
28 | int count; | |
8f7b0ba1 | 29 | atomic_long_t refs; |
74c3cbe3 AV |
30 | struct rcu_head head; |
31 | struct node { | |
32 | struct list_head list; | |
33 | struct audit_tree *owner; | |
34 | unsigned index; /* index; upper bit indicates 'will prune' */ | |
35 | } owners[]; | |
36 | }; | |
37 | ||
38 | static LIST_HEAD(tree_list); | |
39 | static LIST_HEAD(prune_list); | |
40 | ||
41 | /* | |
42 | * One struct chunk is attached to each inode of interest. | |
43 | * We replace struct chunk on tagging/untagging. | |
44 | * Rules have pointer to struct audit_tree. | |
45 | * Rules have struct list_head rlist forming a list of rules over | |
46 | * the same tree. | |
47 | * References to struct chunk are collected at audit_inode{,_child}() | |
48 | * time and used in AUDIT_TREE rule matching. | |
49 | * These references are dropped at the same time we are calling | |
50 | * audit_free_names(), etc. | |
51 | * | |
52 | * Cyclic lists galore: | |
53 | * tree.chunks anchors chunk.owners[].list hash_lock | |
54 | * tree.rules anchors rule.rlist audit_filter_mutex | |
55 | * chunk.trees anchors tree.same_root hash_lock | |
56 | * chunk.hash is a hash with middle bits of watch.inode as | |
57 | * a hash function. RCU, hash_lock | |
58 | * | |
59 | * tree is refcounted; one reference for "some rules on rules_list refer to | |
60 | * it", one for each chunk with pointer to it. | |
61 | * | |
8f7b0ba1 AV |
62 | * chunk is refcounted by embedded inotify_watch + .refs (non-zero refcount |
63 | * of watch contributes 1 to .refs). | |
74c3cbe3 AV |
64 | * |
65 | * node.index allows to get from node.list to containing chunk. | |
66 | * MSB of that sucker is stolen to mark taggings that we might have to | |
67 | * revert - several operations have very unpleasant cleanup logics and | |
68 | * that makes a difference. Some. | |
69 | */ | |
70 | ||
71 | static struct inotify_handle *rtree_ih; | |
72 | ||
73 | static struct audit_tree *alloc_tree(const char *s) | |
74 | { | |
75 | struct audit_tree *tree; | |
76 | ||
77 | tree = kmalloc(sizeof(struct audit_tree) + strlen(s) + 1, GFP_KERNEL); | |
78 | if (tree) { | |
79 | atomic_set(&tree->count, 1); | |
80 | tree->goner = 0; | |
81 | INIT_LIST_HEAD(&tree->chunks); | |
82 | INIT_LIST_HEAD(&tree->rules); | |
83 | INIT_LIST_HEAD(&tree->list); | |
84 | INIT_LIST_HEAD(&tree->same_root); | |
85 | tree->root = NULL; | |
86 | strcpy(tree->pathname, s); | |
87 | } | |
88 | return tree; | |
89 | } | |
90 | ||
91 | static inline void get_tree(struct audit_tree *tree) | |
92 | { | |
93 | atomic_inc(&tree->count); | |
94 | } | |
95 | ||
96 | static void __put_tree(struct rcu_head *rcu) | |
97 | { | |
98 | struct audit_tree *tree = container_of(rcu, struct audit_tree, head); | |
99 | kfree(tree); | |
100 | } | |
101 | ||
102 | static inline void put_tree(struct audit_tree *tree) | |
103 | { | |
104 | if (atomic_dec_and_test(&tree->count)) | |
105 | call_rcu(&tree->head, __put_tree); | |
106 | } | |
107 | ||
108 | /* to avoid bringing the entire thing in audit.h */ | |
109 | const char *audit_tree_path(struct audit_tree *tree) | |
110 | { | |
111 | return tree->pathname; | |
112 | } | |
113 | ||
114 | static struct audit_chunk *alloc_chunk(int count) | |
115 | { | |
116 | struct audit_chunk *chunk; | |
117 | size_t size; | |
118 | int i; | |
119 | ||
120 | size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node); | |
121 | chunk = kzalloc(size, GFP_KERNEL); | |
122 | if (!chunk) | |
123 | return NULL; | |
124 | ||
125 | INIT_LIST_HEAD(&chunk->hash); | |
126 | INIT_LIST_HEAD(&chunk->trees); | |
127 | chunk->count = count; | |
8f7b0ba1 | 128 | atomic_long_set(&chunk->refs, 1); |
74c3cbe3 AV |
129 | for (i = 0; i < count; i++) { |
130 | INIT_LIST_HEAD(&chunk->owners[i].list); | |
131 | chunk->owners[i].index = i; | |
132 | } | |
133 | inotify_init_watch(&chunk->watch); | |
134 | return chunk; | |
135 | } | |
136 | ||
8f7b0ba1 | 137 | static void free_chunk(struct audit_chunk *chunk) |
74c3cbe3 | 138 | { |
74c3cbe3 AV |
139 | int i; |
140 | ||
141 | for (i = 0; i < chunk->count; i++) { | |
142 | if (chunk->owners[i].owner) | |
143 | put_tree(chunk->owners[i].owner); | |
144 | } | |
145 | kfree(chunk); | |
146 | } | |
147 | ||
8f7b0ba1 | 148 | void audit_put_chunk(struct audit_chunk *chunk) |
74c3cbe3 | 149 | { |
8f7b0ba1 AV |
150 | if (atomic_long_dec_and_test(&chunk->refs)) |
151 | free_chunk(chunk); | |
74c3cbe3 AV |
152 | } |
153 | ||
8f7b0ba1 | 154 | static void __put_chunk(struct rcu_head *rcu) |
74c3cbe3 | 155 | { |
8f7b0ba1 AV |
156 | struct audit_chunk *chunk = container_of(rcu, struct audit_chunk, head); |
157 | audit_put_chunk(chunk); | |
74c3cbe3 AV |
158 | } |
159 | ||
160 | enum {HASH_SIZE = 128}; | |
161 | static struct list_head chunk_hash_heads[HASH_SIZE]; | |
162 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock); | |
163 | ||
164 | static inline struct list_head *chunk_hash(const struct inode *inode) | |
165 | { | |
166 | unsigned long n = (unsigned long)inode / L1_CACHE_BYTES; | |
167 | return chunk_hash_heads + n % HASH_SIZE; | |
168 | } | |
169 | ||
170 | /* hash_lock is held by caller */ | |
171 | static void insert_hash(struct audit_chunk *chunk) | |
172 | { | |
173 | struct list_head *list = chunk_hash(chunk->watch.inode); | |
174 | list_add_rcu(&chunk->hash, list); | |
175 | } | |
176 | ||
177 | /* called under rcu_read_lock */ | |
178 | struct audit_chunk *audit_tree_lookup(const struct inode *inode) | |
179 | { | |
180 | struct list_head *list = chunk_hash(inode); | |
6793a051 | 181 | struct audit_chunk *p; |
74c3cbe3 | 182 | |
6793a051 | 183 | list_for_each_entry_rcu(p, list, hash) { |
74c3cbe3 | 184 | if (p->watch.inode == inode) { |
8f7b0ba1 | 185 | atomic_long_inc(&p->refs); |
74c3cbe3 AV |
186 | return p; |
187 | } | |
188 | } | |
189 | return NULL; | |
190 | } | |
191 | ||
192 | int audit_tree_match(struct audit_chunk *chunk, struct audit_tree *tree) | |
193 | { | |
194 | int n; | |
195 | for (n = 0; n < chunk->count; n++) | |
196 | if (chunk->owners[n].owner == tree) | |
197 | return 1; | |
198 | return 0; | |
199 | } | |
200 | ||
201 | /* tagging and untagging inodes with trees */ | |
202 | ||
8f7b0ba1 AV |
203 | static struct audit_chunk *find_chunk(struct node *p) |
204 | { | |
205 | int index = p->index & ~(1U<<31); | |
206 | p -= index; | |
207 | return container_of(p, struct audit_chunk, owners[0]); | |
208 | } | |
209 | ||
210 | static void untag_chunk(struct node *p) | |
74c3cbe3 | 211 | { |
8f7b0ba1 | 212 | struct audit_chunk *chunk = find_chunk(p); |
74c3cbe3 AV |
213 | struct audit_chunk *new; |
214 | struct audit_tree *owner; | |
215 | int size = chunk->count - 1; | |
216 | int i, j; | |
217 | ||
8f7b0ba1 AV |
218 | if (!pin_inotify_watch(&chunk->watch)) { |
219 | /* | |
220 | * Filesystem is shutting down; all watches are getting | |
221 | * evicted, just take it off the node list for this | |
222 | * tree and let the eviction logics take care of the | |
223 | * rest. | |
224 | */ | |
225 | owner = p->owner; | |
226 | if (owner->root == chunk) { | |
227 | list_del_init(&owner->same_root); | |
228 | owner->root = NULL; | |
229 | } | |
230 | list_del_init(&p->list); | |
231 | p->owner = NULL; | |
232 | put_tree(owner); | |
233 | return; | |
234 | } | |
235 | ||
236 | spin_unlock(&hash_lock); | |
237 | ||
238 | /* | |
239 | * pin_inotify_watch() succeeded, so the watch won't go away | |
240 | * from under us. | |
241 | */ | |
74c3cbe3 AV |
242 | mutex_lock(&chunk->watch.inode->inotify_mutex); |
243 | if (chunk->dead) { | |
244 | mutex_unlock(&chunk->watch.inode->inotify_mutex); | |
8f7b0ba1 | 245 | goto out; |
74c3cbe3 AV |
246 | } |
247 | ||
248 | owner = p->owner; | |
249 | ||
250 | if (!size) { | |
251 | chunk->dead = 1; | |
252 | spin_lock(&hash_lock); | |
253 | list_del_init(&chunk->trees); | |
254 | if (owner->root == chunk) | |
255 | owner->root = NULL; | |
256 | list_del_init(&p->list); | |
257 | list_del_rcu(&chunk->hash); | |
258 | spin_unlock(&hash_lock); | |
259 | inotify_evict_watch(&chunk->watch); | |
260 | mutex_unlock(&chunk->watch.inode->inotify_mutex); | |
261 | put_inotify_watch(&chunk->watch); | |
8f7b0ba1 | 262 | goto out; |
74c3cbe3 AV |
263 | } |
264 | ||
265 | new = alloc_chunk(size); | |
266 | if (!new) | |
267 | goto Fallback; | |
268 | if (inotify_clone_watch(&chunk->watch, &new->watch) < 0) { | |
269 | free_chunk(new); | |
270 | goto Fallback; | |
271 | } | |
272 | ||
273 | chunk->dead = 1; | |
274 | spin_lock(&hash_lock); | |
275 | list_replace_init(&chunk->trees, &new->trees); | |
276 | if (owner->root == chunk) { | |
277 | list_del_init(&owner->same_root); | |
278 | owner->root = NULL; | |
279 | } | |
280 | ||
6f5d5114 | 281 | for (i = j = 0; j <= size; i++, j++) { |
74c3cbe3 AV |
282 | struct audit_tree *s; |
283 | if (&chunk->owners[j] == p) { | |
284 | list_del_init(&p->list); | |
285 | i--; | |
286 | continue; | |
287 | } | |
288 | s = chunk->owners[j].owner; | |
289 | new->owners[i].owner = s; | |
290 | new->owners[i].index = chunk->owners[j].index - j + i; | |
291 | if (!s) /* result of earlier fallback */ | |
292 | continue; | |
293 | get_tree(s); | |
6f5d5114 | 294 | list_replace_init(&chunk->owners[j].list, &new->owners[i].list); |
74c3cbe3 AV |
295 | } |
296 | ||
297 | list_replace_rcu(&chunk->hash, &new->hash); | |
298 | list_for_each_entry(owner, &new->trees, same_root) | |
299 | owner->root = new; | |
300 | spin_unlock(&hash_lock); | |
301 | inotify_evict_watch(&chunk->watch); | |
302 | mutex_unlock(&chunk->watch.inode->inotify_mutex); | |
303 | put_inotify_watch(&chunk->watch); | |
8f7b0ba1 | 304 | goto out; |
74c3cbe3 AV |
305 | |
306 | Fallback: | |
307 | // do the best we can | |
308 | spin_lock(&hash_lock); | |
309 | if (owner->root == chunk) { | |
310 | list_del_init(&owner->same_root); | |
311 | owner->root = NULL; | |
312 | } | |
313 | list_del_init(&p->list); | |
314 | p->owner = NULL; | |
315 | put_tree(owner); | |
316 | spin_unlock(&hash_lock); | |
317 | mutex_unlock(&chunk->watch.inode->inotify_mutex); | |
8f7b0ba1 AV |
318 | out: |
319 | unpin_inotify_watch(&chunk->watch); | |
320 | spin_lock(&hash_lock); | |
74c3cbe3 AV |
321 | } |
322 | ||
323 | static int create_chunk(struct inode *inode, struct audit_tree *tree) | |
324 | { | |
325 | struct audit_chunk *chunk = alloc_chunk(1); | |
326 | if (!chunk) | |
327 | return -ENOMEM; | |
328 | ||
329 | if (inotify_add_watch(rtree_ih, &chunk->watch, inode, IN_IGNORED | IN_DELETE_SELF) < 0) { | |
330 | free_chunk(chunk); | |
331 | return -ENOSPC; | |
332 | } | |
333 | ||
334 | mutex_lock(&inode->inotify_mutex); | |
335 | spin_lock(&hash_lock); | |
336 | if (tree->goner) { | |
337 | spin_unlock(&hash_lock); | |
338 | chunk->dead = 1; | |
339 | inotify_evict_watch(&chunk->watch); | |
340 | mutex_unlock(&inode->inotify_mutex); | |
341 | put_inotify_watch(&chunk->watch); | |
342 | return 0; | |
343 | } | |
344 | chunk->owners[0].index = (1U << 31); | |
345 | chunk->owners[0].owner = tree; | |
346 | get_tree(tree); | |
347 | list_add(&chunk->owners[0].list, &tree->chunks); | |
348 | if (!tree->root) { | |
349 | tree->root = chunk; | |
350 | list_add(&tree->same_root, &chunk->trees); | |
351 | } | |
352 | insert_hash(chunk); | |
353 | spin_unlock(&hash_lock); | |
354 | mutex_unlock(&inode->inotify_mutex); | |
355 | return 0; | |
356 | } | |
357 | ||
358 | /* the first tagged inode becomes root of tree */ | |
359 | static int tag_chunk(struct inode *inode, struct audit_tree *tree) | |
360 | { | |
361 | struct inotify_watch *watch; | |
362 | struct audit_tree *owner; | |
363 | struct audit_chunk *chunk, *old; | |
364 | struct node *p; | |
365 | int n; | |
366 | ||
367 | if (inotify_find_watch(rtree_ih, inode, &watch) < 0) | |
368 | return create_chunk(inode, tree); | |
369 | ||
370 | old = container_of(watch, struct audit_chunk, watch); | |
371 | ||
372 | /* are we already there? */ | |
373 | spin_lock(&hash_lock); | |
374 | for (n = 0; n < old->count; n++) { | |
375 | if (old->owners[n].owner == tree) { | |
376 | spin_unlock(&hash_lock); | |
b4c30aad | 377 | put_inotify_watch(&old->watch); |
74c3cbe3 AV |
378 | return 0; |
379 | } | |
380 | } | |
381 | spin_unlock(&hash_lock); | |
382 | ||
383 | chunk = alloc_chunk(old->count + 1); | |
b4c30aad AV |
384 | if (!chunk) { |
385 | put_inotify_watch(&old->watch); | |
74c3cbe3 | 386 | return -ENOMEM; |
b4c30aad | 387 | } |
74c3cbe3 AV |
388 | |
389 | mutex_lock(&inode->inotify_mutex); | |
390 | if (inotify_clone_watch(&old->watch, &chunk->watch) < 0) { | |
391 | mutex_unlock(&inode->inotify_mutex); | |
318b6d3d | 392 | put_inotify_watch(&old->watch); |
74c3cbe3 AV |
393 | free_chunk(chunk); |
394 | return -ENOSPC; | |
395 | } | |
396 | spin_lock(&hash_lock); | |
397 | if (tree->goner) { | |
398 | spin_unlock(&hash_lock); | |
399 | chunk->dead = 1; | |
400 | inotify_evict_watch(&chunk->watch); | |
401 | mutex_unlock(&inode->inotify_mutex); | |
318b6d3d | 402 | put_inotify_watch(&old->watch); |
74c3cbe3 AV |
403 | put_inotify_watch(&chunk->watch); |
404 | return 0; | |
405 | } | |
406 | list_replace_init(&old->trees, &chunk->trees); | |
407 | for (n = 0, p = chunk->owners; n < old->count; n++, p++) { | |
408 | struct audit_tree *s = old->owners[n].owner; | |
409 | p->owner = s; | |
410 | p->index = old->owners[n].index; | |
411 | if (!s) /* result of fallback in untag */ | |
412 | continue; | |
413 | get_tree(s); | |
414 | list_replace_init(&old->owners[n].list, &p->list); | |
415 | } | |
416 | p->index = (chunk->count - 1) | (1U<<31); | |
417 | p->owner = tree; | |
418 | get_tree(tree); | |
419 | list_add(&p->list, &tree->chunks); | |
420 | list_replace_rcu(&old->hash, &chunk->hash); | |
421 | list_for_each_entry(owner, &chunk->trees, same_root) | |
422 | owner->root = chunk; | |
423 | old->dead = 1; | |
424 | if (!tree->root) { | |
425 | tree->root = chunk; | |
426 | list_add(&tree->same_root, &chunk->trees); | |
427 | } | |
428 | spin_unlock(&hash_lock); | |
429 | inotify_evict_watch(&old->watch); | |
430 | mutex_unlock(&inode->inotify_mutex); | |
b4c30aad AV |
431 | put_inotify_watch(&old->watch); /* pair to inotify_find_watch */ |
432 | put_inotify_watch(&old->watch); /* and kill it */ | |
74c3cbe3 AV |
433 | return 0; |
434 | } | |
435 | ||
74c3cbe3 AV |
436 | static void kill_rules(struct audit_tree *tree) |
437 | { | |
438 | struct audit_krule *rule, *next; | |
439 | struct audit_entry *entry; | |
440 | struct audit_buffer *ab; | |
441 | ||
442 | list_for_each_entry_safe(rule, next, &tree->rules, rlist) { | |
443 | entry = container_of(rule, struct audit_entry, rule); | |
444 | ||
445 | list_del_init(&rule->rlist); | |
446 | if (rule->tree) { | |
447 | /* not a half-baked one */ | |
448 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); | |
9d960985 EP |
449 | audit_log_format(ab, "op="); |
450 | audit_log_string(ab, "remove rule"); | |
451 | audit_log_format(ab, " dir="); | |
74c3cbe3 | 452 | audit_log_untrustedstring(ab, rule->tree->pathname); |
9d960985 | 453 | audit_log_key(ab, rule->filterkey); |
74c3cbe3 AV |
454 | audit_log_format(ab, " list=%d res=1", rule->listnr); |
455 | audit_log_end(ab); | |
456 | rule->tree = NULL; | |
457 | list_del_rcu(&entry->list); | |
e45aa212 | 458 | list_del(&entry->rule.list); |
74c3cbe3 AV |
459 | call_rcu(&entry->rcu, audit_free_rule_rcu); |
460 | } | |
461 | } | |
462 | } | |
463 | ||
464 | /* | |
465 | * finish killing struct audit_tree | |
466 | */ | |
467 | static void prune_one(struct audit_tree *victim) | |
468 | { | |
469 | spin_lock(&hash_lock); | |
470 | while (!list_empty(&victim->chunks)) { | |
471 | struct node *p; | |
74c3cbe3 AV |
472 | |
473 | p = list_entry(victim->chunks.next, struct node, list); | |
74c3cbe3 | 474 | |
8f7b0ba1 | 475 | untag_chunk(p); |
74c3cbe3 AV |
476 | } |
477 | spin_unlock(&hash_lock); | |
478 | put_tree(victim); | |
479 | } | |
480 | ||
481 | /* trim the uncommitted chunks from tree */ | |
482 | ||
483 | static void trim_marked(struct audit_tree *tree) | |
484 | { | |
485 | struct list_head *p, *q; | |
486 | spin_lock(&hash_lock); | |
487 | if (tree->goner) { | |
488 | spin_unlock(&hash_lock); | |
489 | return; | |
490 | } | |
491 | /* reorder */ | |
492 | for (p = tree->chunks.next; p != &tree->chunks; p = q) { | |
493 | struct node *node = list_entry(p, struct node, list); | |
494 | q = p->next; | |
495 | if (node->index & (1U<<31)) { | |
496 | list_del_init(p); | |
497 | list_add(p, &tree->chunks); | |
498 | } | |
499 | } | |
500 | ||
501 | while (!list_empty(&tree->chunks)) { | |
502 | struct node *node; | |
74c3cbe3 AV |
503 | |
504 | node = list_entry(tree->chunks.next, struct node, list); | |
505 | ||
506 | /* have we run out of marked? */ | |
507 | if (!(node->index & (1U<<31))) | |
508 | break; | |
509 | ||
8f7b0ba1 | 510 | untag_chunk(node); |
74c3cbe3 AV |
511 | } |
512 | if (!tree->root && !tree->goner) { | |
513 | tree->goner = 1; | |
514 | spin_unlock(&hash_lock); | |
515 | mutex_lock(&audit_filter_mutex); | |
516 | kill_rules(tree); | |
517 | list_del_init(&tree->list); | |
518 | mutex_unlock(&audit_filter_mutex); | |
519 | prune_one(tree); | |
520 | } else { | |
521 | spin_unlock(&hash_lock); | |
522 | } | |
523 | } | |
524 | ||
916d7576 AV |
525 | static void audit_schedule_prune(void); |
526 | ||
74c3cbe3 AV |
527 | /* called with audit_filter_mutex */ |
528 | int audit_remove_tree_rule(struct audit_krule *rule) | |
529 | { | |
530 | struct audit_tree *tree; | |
531 | tree = rule->tree; | |
532 | if (tree) { | |
533 | spin_lock(&hash_lock); | |
534 | list_del_init(&rule->rlist); | |
535 | if (list_empty(&tree->rules) && !tree->goner) { | |
536 | tree->root = NULL; | |
537 | list_del_init(&tree->same_root); | |
538 | tree->goner = 1; | |
539 | list_move(&tree->list, &prune_list); | |
540 | rule->tree = NULL; | |
541 | spin_unlock(&hash_lock); | |
542 | audit_schedule_prune(); | |
543 | return 1; | |
544 | } | |
545 | rule->tree = NULL; | |
546 | spin_unlock(&hash_lock); | |
547 | return 1; | |
548 | } | |
549 | return 0; | |
550 | } | |
551 | ||
1f707137 AV |
552 | static int compare_root(struct vfsmount *mnt, void *arg) |
553 | { | |
554 | return mnt->mnt_root->d_inode == arg; | |
555 | } | |
556 | ||
74c3cbe3 AV |
557 | void audit_trim_trees(void) |
558 | { | |
559 | struct list_head cursor; | |
560 | ||
561 | mutex_lock(&audit_filter_mutex); | |
562 | list_add(&cursor, &tree_list); | |
563 | while (cursor.next != &tree_list) { | |
564 | struct audit_tree *tree; | |
98bc993f | 565 | struct path path; |
74c3cbe3 AV |
566 | struct vfsmount *root_mnt; |
567 | struct node *node; | |
74c3cbe3 AV |
568 | int err; |
569 | ||
570 | tree = container_of(cursor.next, struct audit_tree, list); | |
571 | get_tree(tree); | |
572 | list_del(&cursor); | |
573 | list_add(&cursor, &tree->list); | |
574 | mutex_unlock(&audit_filter_mutex); | |
575 | ||
98bc993f | 576 | err = kern_path(tree->pathname, 0, &path); |
74c3cbe3 AV |
577 | if (err) |
578 | goto skip_it; | |
579 | ||
589ff870 | 580 | root_mnt = collect_mounts(&path); |
98bc993f | 581 | path_put(&path); |
74c3cbe3 AV |
582 | if (!root_mnt) |
583 | goto skip_it; | |
584 | ||
74c3cbe3 AV |
585 | spin_lock(&hash_lock); |
586 | list_for_each_entry(node, &tree->chunks, list) { | |
1f707137 | 587 | struct inode *inode = find_chunk(node)->watch.inode; |
74c3cbe3 | 588 | node->index |= 1U<<31; |
1f707137 AV |
589 | if (iterate_mounts(compare_root, inode, root_mnt)) |
590 | node->index &= ~(1U<<31); | |
74c3cbe3 AV |
591 | } |
592 | spin_unlock(&hash_lock); | |
593 | trim_marked(tree); | |
594 | put_tree(tree); | |
74c3cbe3 AV |
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 | ||
74c3cbe3 AV |
603 | int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op) |
604 | { | |
605 | ||
606 | if (pathname[0] != '/' || | |
607 | rule->listnr != AUDIT_FILTER_EXIT || | |
5af75d8d | 608 | op != Audit_equal || |
74c3cbe3 AV |
609 | rule->inode_f || rule->watch || rule->tree) |
610 | return -EINVAL; | |
611 | rule->tree = alloc_tree(pathname); | |
612 | if (!rule->tree) | |
613 | return -ENOMEM; | |
614 | return 0; | |
615 | } | |
616 | ||
617 | void audit_put_tree(struct audit_tree *tree) | |
618 | { | |
619 | put_tree(tree); | |
620 | } | |
621 | ||
1f707137 AV |
622 | static int tag_mount(struct vfsmount *mnt, void *arg) |
623 | { | |
624 | return tag_chunk(mnt->mnt_root->d_inode, arg); | |
625 | } | |
626 | ||
74c3cbe3 AV |
627 | /* called with audit_filter_mutex */ |
628 | int audit_add_tree_rule(struct audit_krule *rule) | |
629 | { | |
630 | struct audit_tree *seed = rule->tree, *tree; | |
98bc993f | 631 | struct path path; |
1f707137 | 632 | struct vfsmount *mnt; |
74c3cbe3 AV |
633 | int err; |
634 | ||
635 | list_for_each_entry(tree, &tree_list, list) { | |
636 | if (!strcmp(seed->pathname, tree->pathname)) { | |
637 | put_tree(seed); | |
638 | rule->tree = tree; | |
639 | list_add(&rule->rlist, &tree->rules); | |
640 | return 0; | |
641 | } | |
642 | } | |
643 | tree = seed; | |
644 | list_add(&tree->list, &tree_list); | |
645 | list_add(&rule->rlist, &tree->rules); | |
646 | /* do not set rule->tree yet */ | |
647 | mutex_unlock(&audit_filter_mutex); | |
648 | ||
98bc993f | 649 | err = kern_path(tree->pathname, 0, &path); |
74c3cbe3 AV |
650 | if (err) |
651 | goto Err; | |
589ff870 | 652 | mnt = collect_mounts(&path); |
98bc993f | 653 | path_put(&path); |
74c3cbe3 AV |
654 | if (!mnt) { |
655 | err = -ENOMEM; | |
656 | goto Err; | |
657 | } | |
74c3cbe3 AV |
658 | |
659 | get_tree(tree); | |
1f707137 | 660 | err = iterate_mounts(tag_mount, tree, mnt); |
74c3cbe3 AV |
661 | drop_collected_mounts(mnt); |
662 | ||
663 | if (!err) { | |
664 | struct node *node; | |
665 | spin_lock(&hash_lock); | |
666 | list_for_each_entry(node, &tree->chunks, list) | |
667 | node->index &= ~(1U<<31); | |
668 | spin_unlock(&hash_lock); | |
669 | } else { | |
670 | trim_marked(tree); | |
671 | goto Err; | |
672 | } | |
673 | ||
674 | mutex_lock(&audit_filter_mutex); | |
675 | if (list_empty(&rule->rlist)) { | |
676 | put_tree(tree); | |
677 | return -ENOENT; | |
678 | } | |
679 | rule->tree = tree; | |
680 | put_tree(tree); | |
681 | ||
682 | return 0; | |
683 | Err: | |
684 | mutex_lock(&audit_filter_mutex); | |
685 | list_del_init(&tree->list); | |
686 | list_del_init(&tree->rules); | |
687 | put_tree(tree); | |
688 | return err; | |
689 | } | |
690 | ||
691 | int audit_tag_tree(char *old, char *new) | |
692 | { | |
693 | struct list_head cursor, barrier; | |
694 | int failed = 0; | |
2096f759 | 695 | struct path path1, path2; |
74c3cbe3 | 696 | struct vfsmount *tagged; |
74c3cbe3 AV |
697 | int err; |
698 | ||
2096f759 | 699 | err = kern_path(new, 0, &path2); |
74c3cbe3 AV |
700 | if (err) |
701 | return err; | |
2096f759 AV |
702 | tagged = collect_mounts(&path2); |
703 | path_put(&path2); | |
74c3cbe3 AV |
704 | if (!tagged) |
705 | return -ENOMEM; | |
706 | ||
2096f759 | 707 | err = kern_path(old, 0, &path1); |
74c3cbe3 AV |
708 | if (err) { |
709 | drop_collected_mounts(tagged); | |
710 | return err; | |
711 | } | |
74c3cbe3 | 712 | |
74c3cbe3 AV |
713 | mutex_lock(&audit_filter_mutex); |
714 | list_add(&barrier, &tree_list); | |
715 | list_add(&cursor, &barrier); | |
716 | ||
717 | while (cursor.next != &tree_list) { | |
718 | struct audit_tree *tree; | |
2096f759 | 719 | int good_one = 0; |
74c3cbe3 AV |
720 | |
721 | tree = container_of(cursor.next, struct audit_tree, list); | |
722 | get_tree(tree); | |
723 | list_del(&cursor); | |
724 | list_add(&cursor, &tree->list); | |
725 | mutex_unlock(&audit_filter_mutex); | |
726 | ||
2096f759 AV |
727 | err = kern_path(tree->pathname, 0, &path2); |
728 | if (!err) { | |
729 | good_one = path_is_under(&path1, &path2); | |
730 | path_put(&path2); | |
74c3cbe3 AV |
731 | } |
732 | ||
2096f759 | 733 | if (!good_one) { |
74c3cbe3 AV |
734 | put_tree(tree); |
735 | mutex_lock(&audit_filter_mutex); | |
736 | continue; | |
737 | } | |
74c3cbe3 | 738 | |
1f707137 | 739 | failed = iterate_mounts(tag_mount, tree, tagged); |
74c3cbe3 AV |
740 | if (failed) { |
741 | put_tree(tree); | |
742 | mutex_lock(&audit_filter_mutex); | |
743 | break; | |
744 | } | |
745 | ||
746 | mutex_lock(&audit_filter_mutex); | |
747 | spin_lock(&hash_lock); | |
748 | if (!tree->goner) { | |
749 | list_del(&tree->list); | |
750 | list_add(&tree->list, &tree_list); | |
751 | } | |
752 | spin_unlock(&hash_lock); | |
753 | put_tree(tree); | |
754 | } | |
755 | ||
756 | while (barrier.prev != &tree_list) { | |
757 | struct audit_tree *tree; | |
758 | ||
759 | tree = container_of(barrier.prev, struct audit_tree, list); | |
760 | get_tree(tree); | |
761 | list_del(&tree->list); | |
762 | list_add(&tree->list, &barrier); | |
763 | mutex_unlock(&audit_filter_mutex); | |
764 | ||
765 | if (!failed) { | |
766 | struct node *node; | |
767 | spin_lock(&hash_lock); | |
768 | list_for_each_entry(node, &tree->chunks, list) | |
769 | node->index &= ~(1U<<31); | |
770 | spin_unlock(&hash_lock); | |
771 | } else { | |
772 | trim_marked(tree); | |
773 | } | |
774 | ||
775 | put_tree(tree); | |
776 | mutex_lock(&audit_filter_mutex); | |
777 | } | |
778 | list_del(&barrier); | |
779 | list_del(&cursor); | |
74c3cbe3 | 780 | mutex_unlock(&audit_filter_mutex); |
2096f759 | 781 | path_put(&path1); |
74c3cbe3 AV |
782 | drop_collected_mounts(tagged); |
783 | return failed; | |
784 | } | |
785 | ||
786 | /* | |
787 | * That gets run when evict_chunk() ends up needing to kill audit_tree. | |
916d7576 | 788 | * Runs from a separate thread. |
74c3cbe3 | 789 | */ |
916d7576 | 790 | static int prune_tree_thread(void *unused) |
74c3cbe3 | 791 | { |
916d7576 | 792 | mutex_lock(&audit_cmd_mutex); |
74c3cbe3 AV |
793 | mutex_lock(&audit_filter_mutex); |
794 | ||
795 | while (!list_empty(&prune_list)) { | |
796 | struct audit_tree *victim; | |
797 | ||
798 | victim = list_entry(prune_list.next, struct audit_tree, list); | |
799 | list_del_init(&victim->list); | |
800 | ||
801 | mutex_unlock(&audit_filter_mutex); | |
802 | ||
803 | prune_one(victim); | |
804 | ||
805 | mutex_lock(&audit_filter_mutex); | |
806 | } | |
807 | ||
808 | mutex_unlock(&audit_filter_mutex); | |
916d7576 AV |
809 | mutex_unlock(&audit_cmd_mutex); |
810 | return 0; | |
811 | } | |
812 | ||
813 | static void audit_schedule_prune(void) | |
814 | { | |
815 | kthread_run(prune_tree_thread, NULL, "audit_prune_tree"); | |
816 | } | |
817 | ||
818 | /* | |
819 | * ... and that one is done if evict_chunk() decides to delay until the end | |
820 | * of syscall. Runs synchronously. | |
821 | */ | |
822 | void audit_kill_trees(struct list_head *list) | |
823 | { | |
824 | mutex_lock(&audit_cmd_mutex); | |
825 | mutex_lock(&audit_filter_mutex); | |
826 | ||
827 | while (!list_empty(list)) { | |
828 | struct audit_tree *victim; | |
829 | ||
830 | victim = list_entry(list->next, struct audit_tree, list); | |
831 | kill_rules(victim); | |
832 | list_del_init(&victim->list); | |
833 | ||
834 | mutex_unlock(&audit_filter_mutex); | |
835 | ||
836 | prune_one(victim); | |
837 | ||
838 | mutex_lock(&audit_filter_mutex); | |
839 | } | |
840 | ||
841 | mutex_unlock(&audit_filter_mutex); | |
842 | mutex_unlock(&audit_cmd_mutex); | |
74c3cbe3 AV |
843 | } |
844 | ||
845 | /* | |
846 | * Here comes the stuff asynchronous to auditctl operations | |
847 | */ | |
848 | ||
849 | /* inode->inotify_mutex is locked */ | |
850 | static void evict_chunk(struct audit_chunk *chunk) | |
851 | { | |
852 | struct audit_tree *owner; | |
916d7576 AV |
853 | struct list_head *postponed = audit_killed_trees(); |
854 | int need_prune = 0; | |
74c3cbe3 AV |
855 | int n; |
856 | ||
857 | if (chunk->dead) | |
858 | return; | |
859 | ||
860 | chunk->dead = 1; | |
861 | mutex_lock(&audit_filter_mutex); | |
862 | spin_lock(&hash_lock); | |
863 | while (!list_empty(&chunk->trees)) { | |
864 | owner = list_entry(chunk->trees.next, | |
865 | struct audit_tree, same_root); | |
866 | owner->goner = 1; | |
867 | owner->root = NULL; | |
868 | list_del_init(&owner->same_root); | |
869 | spin_unlock(&hash_lock); | |
916d7576 AV |
870 | if (!postponed) { |
871 | kill_rules(owner); | |
872 | list_move(&owner->list, &prune_list); | |
873 | need_prune = 1; | |
874 | } else { | |
875 | list_move(&owner->list, postponed); | |
876 | } | |
74c3cbe3 AV |
877 | spin_lock(&hash_lock); |
878 | } | |
879 | list_del_rcu(&chunk->hash); | |
880 | for (n = 0; n < chunk->count; n++) | |
881 | list_del_init(&chunk->owners[n].list); | |
882 | spin_unlock(&hash_lock); | |
916d7576 AV |
883 | if (need_prune) |
884 | audit_schedule_prune(); | |
74c3cbe3 AV |
885 | mutex_unlock(&audit_filter_mutex); |
886 | } | |
887 | ||
888 | static void handle_event(struct inotify_watch *watch, u32 wd, u32 mask, | |
889 | u32 cookie, const char *dname, struct inode *inode) | |
890 | { | |
891 | struct audit_chunk *chunk = container_of(watch, struct audit_chunk, watch); | |
892 | ||
893 | if (mask & IN_IGNORED) { | |
894 | evict_chunk(chunk); | |
895 | put_inotify_watch(watch); | |
896 | } | |
897 | } | |
898 | ||
899 | static void destroy_watch(struct inotify_watch *watch) | |
900 | { | |
901 | struct audit_chunk *chunk = container_of(watch, struct audit_chunk, watch); | |
8f7b0ba1 | 902 | call_rcu(&chunk->head, __put_chunk); |
74c3cbe3 AV |
903 | } |
904 | ||
905 | static const struct inotify_operations rtree_inotify_ops = { | |
906 | .handle_event = handle_event, | |
907 | .destroy_watch = destroy_watch, | |
908 | }; | |
909 | ||
910 | static int __init audit_tree_init(void) | |
911 | { | |
912 | int i; | |
913 | ||
914 | rtree_ih = inotify_init(&rtree_inotify_ops); | |
915 | if (IS_ERR(rtree_ih)) | |
916 | audit_panic("cannot initialize inotify handle for rectree watches"); | |
917 | ||
918 | for (i = 0; i < HASH_SIZE; i++) | |
919 | INIT_LIST_HEAD(&chunk_hash_heads[i]); | |
920 | ||
921 | return 0; | |
922 | } | |
923 | __initcall(audit_tree_init); |