Commit | Line | Data |
---|---|---|
74c3cbe3 | 1 | #include "audit.h" |
28a3a7eb | 2 | #include <linux/fsnotify_backend.h> |
74c3cbe3 AV |
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; | |
e61ce867 | 25 | struct fsnotify_mark mark; |
74c3cbe3 AV |
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 | * | |
28a3a7eb | 62 | * chunk is refcounted by embedded fsnotify_mark + .refs (non-zero refcount |
8f7b0ba1 | 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 | ||
28a3a7eb | 71 | static struct fsnotify_group *audit_tree_group; |
74c3cbe3 AV |
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 | ||
8f7b0ba1 | 114 | static void free_chunk(struct audit_chunk *chunk) |
74c3cbe3 | 115 | { |
74c3cbe3 AV |
116 | int i; |
117 | ||
118 | for (i = 0; i < chunk->count; i++) { | |
119 | if (chunk->owners[i].owner) | |
120 | put_tree(chunk->owners[i].owner); | |
121 | } | |
122 | kfree(chunk); | |
123 | } | |
124 | ||
8f7b0ba1 | 125 | void audit_put_chunk(struct audit_chunk *chunk) |
74c3cbe3 | 126 | { |
8f7b0ba1 AV |
127 | if (atomic_long_dec_and_test(&chunk->refs)) |
128 | free_chunk(chunk); | |
74c3cbe3 AV |
129 | } |
130 | ||
8f7b0ba1 | 131 | static void __put_chunk(struct rcu_head *rcu) |
74c3cbe3 | 132 | { |
8f7b0ba1 AV |
133 | struct audit_chunk *chunk = container_of(rcu, struct audit_chunk, head); |
134 | audit_put_chunk(chunk); | |
74c3cbe3 AV |
135 | } |
136 | ||
e61ce867 | 137 | static void audit_tree_destroy_watch(struct fsnotify_mark *entry) |
28a3a7eb EP |
138 | { |
139 | struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark); | |
140 | call_rcu(&chunk->head, __put_chunk); | |
141 | } | |
142 | ||
143 | static struct audit_chunk *alloc_chunk(int count) | |
144 | { | |
145 | struct audit_chunk *chunk; | |
146 | size_t size; | |
147 | int i; | |
148 | ||
149 | size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node); | |
150 | chunk = kzalloc(size, GFP_KERNEL); | |
151 | if (!chunk) | |
152 | return NULL; | |
153 | ||
154 | INIT_LIST_HEAD(&chunk->hash); | |
155 | INIT_LIST_HEAD(&chunk->trees); | |
156 | chunk->count = count; | |
157 | atomic_long_set(&chunk->refs, 1); | |
158 | for (i = 0; i < count; i++) { | |
159 | INIT_LIST_HEAD(&chunk->owners[i].list); | |
160 | chunk->owners[i].index = i; | |
161 | } | |
162 | fsnotify_init_mark(&chunk->mark, audit_tree_destroy_watch); | |
163 | return chunk; | |
164 | } | |
165 | ||
74c3cbe3 AV |
166 | enum {HASH_SIZE = 128}; |
167 | static struct list_head chunk_hash_heads[HASH_SIZE]; | |
168 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock); | |
169 | ||
170 | static inline struct list_head *chunk_hash(const struct inode *inode) | |
171 | { | |
172 | unsigned long n = (unsigned long)inode / L1_CACHE_BYTES; | |
173 | return chunk_hash_heads + n % HASH_SIZE; | |
174 | } | |
175 | ||
28a3a7eb | 176 | /* hash_lock & entry->lock is held by caller */ |
74c3cbe3 AV |
177 | static void insert_hash(struct audit_chunk *chunk) |
178 | { | |
e61ce867 | 179 | struct fsnotify_mark *entry = &chunk->mark; |
28a3a7eb EP |
180 | struct list_head *list; |
181 | ||
2823e04d | 182 | if (!entry->i.inode) |
28a3a7eb | 183 | return; |
2823e04d | 184 | list = chunk_hash(entry->i.inode); |
74c3cbe3 AV |
185 | list_add_rcu(&chunk->hash, list); |
186 | } | |
187 | ||
188 | /* called under rcu_read_lock */ | |
189 | struct audit_chunk *audit_tree_lookup(const struct inode *inode) | |
190 | { | |
191 | struct list_head *list = chunk_hash(inode); | |
6793a051 | 192 | struct audit_chunk *p; |
74c3cbe3 | 193 | |
6793a051 | 194 | list_for_each_entry_rcu(p, list, hash) { |
28a3a7eb | 195 | /* mark.inode may have gone NULL, but who cares? */ |
2823e04d | 196 | if (p->mark.i.inode == inode) { |
8f7b0ba1 | 197 | atomic_long_inc(&p->refs); |
74c3cbe3 AV |
198 | return p; |
199 | } | |
200 | } | |
201 | return NULL; | |
202 | } | |
203 | ||
204 | int audit_tree_match(struct audit_chunk *chunk, struct audit_tree *tree) | |
205 | { | |
206 | int n; | |
207 | for (n = 0; n < chunk->count; n++) | |
208 | if (chunk->owners[n].owner == tree) | |
209 | return 1; | |
210 | return 0; | |
211 | } | |
212 | ||
213 | /* tagging and untagging inodes with trees */ | |
214 | ||
8f7b0ba1 AV |
215 | static struct audit_chunk *find_chunk(struct node *p) |
216 | { | |
217 | int index = p->index & ~(1U<<31); | |
218 | p -= index; | |
219 | return container_of(p, struct audit_chunk, owners[0]); | |
220 | } | |
221 | ||
222 | static void untag_chunk(struct node *p) | |
74c3cbe3 | 223 | { |
8f7b0ba1 | 224 | struct audit_chunk *chunk = find_chunk(p); |
e61ce867 | 225 | struct fsnotify_mark *entry = &chunk->mark; |
74c3cbe3 AV |
226 | struct audit_chunk *new; |
227 | struct audit_tree *owner; | |
228 | int size = chunk->count - 1; | |
229 | int i, j; | |
230 | ||
28a3a7eb | 231 | fsnotify_get_mark(entry); |
8f7b0ba1 AV |
232 | |
233 | spin_unlock(&hash_lock); | |
234 | ||
28a3a7eb | 235 | spin_lock(&entry->lock); |
2823e04d | 236 | if (chunk->dead || !entry->i.inode) { |
28a3a7eb | 237 | spin_unlock(&entry->lock); |
8f7b0ba1 | 238 | goto out; |
74c3cbe3 AV |
239 | } |
240 | ||
241 | owner = p->owner; | |
242 | ||
243 | if (!size) { | |
244 | chunk->dead = 1; | |
245 | spin_lock(&hash_lock); | |
246 | list_del_init(&chunk->trees); | |
247 | if (owner->root == chunk) | |
248 | owner->root = NULL; | |
249 | list_del_init(&p->list); | |
250 | list_del_rcu(&chunk->hash); | |
251 | spin_unlock(&hash_lock); | |
28a3a7eb | 252 | spin_unlock(&entry->lock); |
d0775441 | 253 | fsnotify_destroy_mark(entry); |
28a3a7eb | 254 | fsnotify_put_mark(entry); |
8f7b0ba1 | 255 | goto out; |
74c3cbe3 AV |
256 | } |
257 | ||
258 | new = alloc_chunk(size); | |
259 | if (!new) | |
260 | goto Fallback; | |
28a3a7eb | 261 | fsnotify_duplicate_mark(&new->mark, entry); |
5444e298 | 262 | if (fsnotify_add_mark(&new->mark, new->mark.group, new->mark.i.inode, NULL, 1)) { |
74c3cbe3 AV |
263 | free_chunk(new); |
264 | goto Fallback; | |
265 | } | |
266 | ||
267 | chunk->dead = 1; | |
268 | spin_lock(&hash_lock); | |
269 | list_replace_init(&chunk->trees, &new->trees); | |
270 | if (owner->root == chunk) { | |
271 | list_del_init(&owner->same_root); | |
272 | owner->root = NULL; | |
273 | } | |
274 | ||
6f5d5114 | 275 | for (i = j = 0; j <= size; i++, j++) { |
74c3cbe3 AV |
276 | struct audit_tree *s; |
277 | if (&chunk->owners[j] == p) { | |
278 | list_del_init(&p->list); | |
279 | i--; | |
280 | continue; | |
281 | } | |
282 | s = chunk->owners[j].owner; | |
283 | new->owners[i].owner = s; | |
284 | new->owners[i].index = chunk->owners[j].index - j + i; | |
285 | if (!s) /* result of earlier fallback */ | |
286 | continue; | |
287 | get_tree(s); | |
6f5d5114 | 288 | list_replace_init(&chunk->owners[j].list, &new->owners[i].list); |
74c3cbe3 AV |
289 | } |
290 | ||
291 | list_replace_rcu(&chunk->hash, &new->hash); | |
292 | list_for_each_entry(owner, &new->trees, same_root) | |
293 | owner->root = new; | |
294 | spin_unlock(&hash_lock); | |
28a3a7eb | 295 | spin_unlock(&entry->lock); |
d0775441 | 296 | fsnotify_destroy_mark(entry); |
28a3a7eb | 297 | fsnotify_put_mark(entry); |
8f7b0ba1 | 298 | goto out; |
74c3cbe3 AV |
299 | |
300 | Fallback: | |
301 | // do the best we can | |
302 | spin_lock(&hash_lock); | |
303 | if (owner->root == chunk) { | |
304 | list_del_init(&owner->same_root); | |
305 | owner->root = NULL; | |
306 | } | |
307 | list_del_init(&p->list); | |
308 | p->owner = NULL; | |
309 | put_tree(owner); | |
310 | spin_unlock(&hash_lock); | |
28a3a7eb | 311 | spin_unlock(&entry->lock); |
8f7b0ba1 | 312 | out: |
28a3a7eb | 313 | fsnotify_put_mark(entry); |
8f7b0ba1 | 314 | spin_lock(&hash_lock); |
74c3cbe3 AV |
315 | } |
316 | ||
317 | static int create_chunk(struct inode *inode, struct audit_tree *tree) | |
318 | { | |
e61ce867 | 319 | struct fsnotify_mark *entry; |
74c3cbe3 AV |
320 | struct audit_chunk *chunk = alloc_chunk(1); |
321 | if (!chunk) | |
322 | return -ENOMEM; | |
323 | ||
28a3a7eb | 324 | entry = &chunk->mark; |
5444e298 | 325 | if (fsnotify_add_mark(entry, audit_tree_group, inode, NULL, 0)) { |
74c3cbe3 AV |
326 | free_chunk(chunk); |
327 | return -ENOSPC; | |
328 | } | |
329 | ||
28a3a7eb | 330 | spin_lock(&entry->lock); |
74c3cbe3 AV |
331 | spin_lock(&hash_lock); |
332 | if (tree->goner) { | |
333 | spin_unlock(&hash_lock); | |
334 | chunk->dead = 1; | |
28a3a7eb | 335 | spin_unlock(&entry->lock); |
d0775441 | 336 | fsnotify_destroy_mark(entry); |
28a3a7eb | 337 | fsnotify_put_mark(entry); |
74c3cbe3 AV |
338 | return 0; |
339 | } | |
340 | chunk->owners[0].index = (1U << 31); | |
341 | chunk->owners[0].owner = tree; | |
342 | get_tree(tree); | |
343 | list_add(&chunk->owners[0].list, &tree->chunks); | |
344 | if (!tree->root) { | |
345 | tree->root = chunk; | |
346 | list_add(&tree->same_root, &chunk->trees); | |
347 | } | |
348 | insert_hash(chunk); | |
349 | spin_unlock(&hash_lock); | |
28a3a7eb | 350 | spin_unlock(&entry->lock); |
74c3cbe3 AV |
351 | return 0; |
352 | } | |
353 | ||
354 | /* the first tagged inode becomes root of tree */ | |
355 | static int tag_chunk(struct inode *inode, struct audit_tree *tree) | |
356 | { | |
e61ce867 | 357 | struct fsnotify_mark *old_entry, *chunk_entry; |
74c3cbe3 AV |
358 | struct audit_tree *owner; |
359 | struct audit_chunk *chunk, *old; | |
360 | struct node *p; | |
361 | int n; | |
362 | ||
5444e298 | 363 | old_entry = fsnotify_find_inode_mark(audit_tree_group, inode); |
28a3a7eb | 364 | if (!old_entry) |
74c3cbe3 AV |
365 | return create_chunk(inode, tree); |
366 | ||
28a3a7eb | 367 | old = container_of(old_entry, struct audit_chunk, mark); |
74c3cbe3 AV |
368 | |
369 | /* are we already there? */ | |
370 | spin_lock(&hash_lock); | |
371 | for (n = 0; n < old->count; n++) { | |
372 | if (old->owners[n].owner == tree) { | |
373 | spin_unlock(&hash_lock); | |
28a3a7eb | 374 | fsnotify_put_mark(old_entry); |
74c3cbe3 AV |
375 | return 0; |
376 | } | |
377 | } | |
378 | spin_unlock(&hash_lock); | |
379 | ||
380 | chunk = alloc_chunk(old->count + 1); | |
b4c30aad | 381 | if (!chunk) { |
28a3a7eb | 382 | fsnotify_put_mark(old_entry); |
74c3cbe3 | 383 | return -ENOMEM; |
b4c30aad | 384 | } |
74c3cbe3 | 385 | |
28a3a7eb EP |
386 | chunk_entry = &chunk->mark; |
387 | ||
388 | spin_lock(&old_entry->lock); | |
2823e04d | 389 | if (!old_entry->i.inode) { |
28a3a7eb EP |
390 | /* old_entry is being shot, lets just lie */ |
391 | spin_unlock(&old_entry->lock); | |
392 | fsnotify_put_mark(old_entry); | |
74c3cbe3 | 393 | free_chunk(chunk); |
28a3a7eb EP |
394 | return -ENOENT; |
395 | } | |
396 | ||
397 | fsnotify_duplicate_mark(chunk_entry, old_entry); | |
5444e298 | 398 | if (fsnotify_add_mark(chunk_entry, chunk_entry->group, chunk_entry->i.inode, NULL, 1)) { |
28a3a7eb EP |
399 | spin_unlock(&old_entry->lock); |
400 | free_chunk(chunk); | |
401 | fsnotify_put_mark(old_entry); | |
74c3cbe3 AV |
402 | return -ENOSPC; |
403 | } | |
28a3a7eb EP |
404 | |
405 | /* even though we hold old_entry->lock, this is safe since chunk_entry->lock could NEVER have been grabbed before */ | |
406 | spin_lock(&chunk_entry->lock); | |
74c3cbe3 | 407 | spin_lock(&hash_lock); |
28a3a7eb EP |
408 | |
409 | /* we now hold old_entry->lock, chunk_entry->lock, and hash_lock */ | |
74c3cbe3 AV |
410 | if (tree->goner) { |
411 | spin_unlock(&hash_lock); | |
412 | chunk->dead = 1; | |
28a3a7eb EP |
413 | spin_unlock(&chunk_entry->lock); |
414 | spin_unlock(&old_entry->lock); | |
415 | ||
d0775441 | 416 | fsnotify_destroy_mark(chunk_entry); |
28a3a7eb EP |
417 | |
418 | fsnotify_put_mark(chunk_entry); | |
419 | fsnotify_put_mark(old_entry); | |
74c3cbe3 AV |
420 | return 0; |
421 | } | |
422 | list_replace_init(&old->trees, &chunk->trees); | |
423 | for (n = 0, p = chunk->owners; n < old->count; n++, p++) { | |
424 | struct audit_tree *s = old->owners[n].owner; | |
425 | p->owner = s; | |
426 | p->index = old->owners[n].index; | |
427 | if (!s) /* result of fallback in untag */ | |
428 | continue; | |
429 | get_tree(s); | |
430 | list_replace_init(&old->owners[n].list, &p->list); | |
431 | } | |
432 | p->index = (chunk->count - 1) | (1U<<31); | |
433 | p->owner = tree; | |
434 | get_tree(tree); | |
435 | list_add(&p->list, &tree->chunks); | |
436 | list_replace_rcu(&old->hash, &chunk->hash); | |
437 | list_for_each_entry(owner, &chunk->trees, same_root) | |
438 | owner->root = chunk; | |
439 | old->dead = 1; | |
440 | if (!tree->root) { | |
441 | tree->root = chunk; | |
442 | list_add(&tree->same_root, &chunk->trees); | |
443 | } | |
444 | spin_unlock(&hash_lock); | |
28a3a7eb EP |
445 | spin_unlock(&chunk_entry->lock); |
446 | spin_unlock(&old_entry->lock); | |
d0775441 | 447 | fsnotify_destroy_mark(old_entry); |
28a3a7eb EP |
448 | fsnotify_put_mark(old_entry); /* pair to fsnotify_find mark_entry */ |
449 | fsnotify_put_mark(old_entry); /* and kill it */ | |
74c3cbe3 AV |
450 | return 0; |
451 | } | |
452 | ||
74c3cbe3 AV |
453 | static void kill_rules(struct audit_tree *tree) |
454 | { | |
455 | struct audit_krule *rule, *next; | |
456 | struct audit_entry *entry; | |
457 | struct audit_buffer *ab; | |
458 | ||
459 | list_for_each_entry_safe(rule, next, &tree->rules, rlist) { | |
460 | entry = container_of(rule, struct audit_entry, rule); | |
461 | ||
462 | list_del_init(&rule->rlist); | |
463 | if (rule->tree) { | |
464 | /* not a half-baked one */ | |
465 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); | |
9d960985 EP |
466 | audit_log_format(ab, "op="); |
467 | audit_log_string(ab, "remove rule"); | |
468 | audit_log_format(ab, " dir="); | |
74c3cbe3 | 469 | audit_log_untrustedstring(ab, rule->tree->pathname); |
9d960985 | 470 | audit_log_key(ab, rule->filterkey); |
74c3cbe3 AV |
471 | audit_log_format(ab, " list=%d res=1", rule->listnr); |
472 | audit_log_end(ab); | |
473 | rule->tree = NULL; | |
474 | list_del_rcu(&entry->list); | |
e45aa212 | 475 | list_del(&entry->rule.list); |
74c3cbe3 AV |
476 | call_rcu(&entry->rcu, audit_free_rule_rcu); |
477 | } | |
478 | } | |
479 | } | |
480 | ||
481 | /* | |
482 | * finish killing struct audit_tree | |
483 | */ | |
484 | static void prune_one(struct audit_tree *victim) | |
485 | { | |
486 | spin_lock(&hash_lock); | |
487 | while (!list_empty(&victim->chunks)) { | |
488 | struct node *p; | |
74c3cbe3 AV |
489 | |
490 | p = list_entry(victim->chunks.next, struct node, list); | |
74c3cbe3 | 491 | |
8f7b0ba1 | 492 | untag_chunk(p); |
74c3cbe3 AV |
493 | } |
494 | spin_unlock(&hash_lock); | |
495 | put_tree(victim); | |
496 | } | |
497 | ||
498 | /* trim the uncommitted chunks from tree */ | |
499 | ||
500 | static void trim_marked(struct audit_tree *tree) | |
501 | { | |
502 | struct list_head *p, *q; | |
503 | spin_lock(&hash_lock); | |
504 | if (tree->goner) { | |
505 | spin_unlock(&hash_lock); | |
506 | return; | |
507 | } | |
508 | /* reorder */ | |
509 | for (p = tree->chunks.next; p != &tree->chunks; p = q) { | |
510 | struct node *node = list_entry(p, struct node, list); | |
511 | q = p->next; | |
512 | if (node->index & (1U<<31)) { | |
513 | list_del_init(p); | |
514 | list_add(p, &tree->chunks); | |
515 | } | |
516 | } | |
517 | ||
518 | while (!list_empty(&tree->chunks)) { | |
519 | struct node *node; | |
74c3cbe3 AV |
520 | |
521 | node = list_entry(tree->chunks.next, struct node, list); | |
522 | ||
523 | /* have we run out of marked? */ | |
524 | if (!(node->index & (1U<<31))) | |
525 | break; | |
526 | ||
8f7b0ba1 | 527 | untag_chunk(node); |
74c3cbe3 AV |
528 | } |
529 | if (!tree->root && !tree->goner) { | |
530 | tree->goner = 1; | |
531 | spin_unlock(&hash_lock); | |
532 | mutex_lock(&audit_filter_mutex); | |
533 | kill_rules(tree); | |
534 | list_del_init(&tree->list); | |
535 | mutex_unlock(&audit_filter_mutex); | |
536 | prune_one(tree); | |
537 | } else { | |
538 | spin_unlock(&hash_lock); | |
539 | } | |
540 | } | |
541 | ||
916d7576 AV |
542 | static void audit_schedule_prune(void); |
543 | ||
74c3cbe3 AV |
544 | /* called with audit_filter_mutex */ |
545 | int audit_remove_tree_rule(struct audit_krule *rule) | |
546 | { | |
547 | struct audit_tree *tree; | |
548 | tree = rule->tree; | |
549 | if (tree) { | |
550 | spin_lock(&hash_lock); | |
551 | list_del_init(&rule->rlist); | |
552 | if (list_empty(&tree->rules) && !tree->goner) { | |
553 | tree->root = NULL; | |
554 | list_del_init(&tree->same_root); | |
555 | tree->goner = 1; | |
556 | list_move(&tree->list, &prune_list); | |
557 | rule->tree = NULL; | |
558 | spin_unlock(&hash_lock); | |
559 | audit_schedule_prune(); | |
560 | return 1; | |
561 | } | |
562 | rule->tree = NULL; | |
563 | spin_unlock(&hash_lock); | |
564 | return 1; | |
565 | } | |
566 | return 0; | |
567 | } | |
568 | ||
1f707137 AV |
569 | static int compare_root(struct vfsmount *mnt, void *arg) |
570 | { | |
571 | return mnt->mnt_root->d_inode == arg; | |
572 | } | |
573 | ||
74c3cbe3 AV |
574 | void audit_trim_trees(void) |
575 | { | |
576 | struct list_head cursor; | |
577 | ||
578 | mutex_lock(&audit_filter_mutex); | |
579 | list_add(&cursor, &tree_list); | |
580 | while (cursor.next != &tree_list) { | |
581 | struct audit_tree *tree; | |
98bc993f | 582 | struct path path; |
74c3cbe3 AV |
583 | struct vfsmount *root_mnt; |
584 | struct node *node; | |
74c3cbe3 AV |
585 | int err; |
586 | ||
587 | tree = container_of(cursor.next, struct audit_tree, list); | |
588 | get_tree(tree); | |
589 | list_del(&cursor); | |
590 | list_add(&cursor, &tree->list); | |
591 | mutex_unlock(&audit_filter_mutex); | |
592 | ||
98bc993f | 593 | err = kern_path(tree->pathname, 0, &path); |
74c3cbe3 AV |
594 | if (err) |
595 | goto skip_it; | |
596 | ||
589ff870 | 597 | root_mnt = collect_mounts(&path); |
98bc993f | 598 | path_put(&path); |
74c3cbe3 AV |
599 | if (!root_mnt) |
600 | goto skip_it; | |
601 | ||
74c3cbe3 AV |
602 | spin_lock(&hash_lock); |
603 | list_for_each_entry(node, &tree->chunks, list) { | |
28a3a7eb EP |
604 | struct audit_chunk *chunk = find_chunk(node); |
605 | /* this could be NULL if the watch is dieing else where... */ | |
2823e04d | 606 | struct inode *inode = chunk->mark.i.inode; |
74c3cbe3 | 607 | node->index |= 1U<<31; |
1f707137 AV |
608 | if (iterate_mounts(compare_root, inode, root_mnt)) |
609 | node->index &= ~(1U<<31); | |
74c3cbe3 AV |
610 | } |
611 | spin_unlock(&hash_lock); | |
612 | trim_marked(tree); | |
613 | put_tree(tree); | |
74c3cbe3 AV |
614 | drop_collected_mounts(root_mnt); |
615 | skip_it: | |
616 | mutex_lock(&audit_filter_mutex); | |
617 | } | |
618 | list_del(&cursor); | |
619 | mutex_unlock(&audit_filter_mutex); | |
620 | } | |
621 | ||
74c3cbe3 AV |
622 | int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op) |
623 | { | |
624 | ||
625 | if (pathname[0] != '/' || | |
626 | rule->listnr != AUDIT_FILTER_EXIT || | |
5af75d8d | 627 | op != Audit_equal || |
74c3cbe3 AV |
628 | rule->inode_f || rule->watch || rule->tree) |
629 | return -EINVAL; | |
630 | rule->tree = alloc_tree(pathname); | |
631 | if (!rule->tree) | |
632 | return -ENOMEM; | |
633 | return 0; | |
634 | } | |
635 | ||
636 | void audit_put_tree(struct audit_tree *tree) | |
637 | { | |
638 | put_tree(tree); | |
639 | } | |
640 | ||
1f707137 AV |
641 | static int tag_mount(struct vfsmount *mnt, void *arg) |
642 | { | |
643 | return tag_chunk(mnt->mnt_root->d_inode, arg); | |
644 | } | |
645 | ||
74c3cbe3 AV |
646 | /* called with audit_filter_mutex */ |
647 | int audit_add_tree_rule(struct audit_krule *rule) | |
648 | { | |
649 | struct audit_tree *seed = rule->tree, *tree; | |
98bc993f | 650 | struct path path; |
1f707137 | 651 | struct vfsmount *mnt; |
74c3cbe3 AV |
652 | int err; |
653 | ||
654 | list_for_each_entry(tree, &tree_list, list) { | |
655 | if (!strcmp(seed->pathname, tree->pathname)) { | |
656 | put_tree(seed); | |
657 | rule->tree = tree; | |
658 | list_add(&rule->rlist, &tree->rules); | |
659 | return 0; | |
660 | } | |
661 | } | |
662 | tree = seed; | |
663 | list_add(&tree->list, &tree_list); | |
664 | list_add(&rule->rlist, &tree->rules); | |
665 | /* do not set rule->tree yet */ | |
666 | mutex_unlock(&audit_filter_mutex); | |
667 | ||
98bc993f | 668 | err = kern_path(tree->pathname, 0, &path); |
74c3cbe3 AV |
669 | if (err) |
670 | goto Err; | |
589ff870 | 671 | mnt = collect_mounts(&path); |
98bc993f | 672 | path_put(&path); |
74c3cbe3 AV |
673 | if (!mnt) { |
674 | err = -ENOMEM; | |
675 | goto Err; | |
676 | } | |
74c3cbe3 AV |
677 | |
678 | get_tree(tree); | |
1f707137 | 679 | err = iterate_mounts(tag_mount, tree, mnt); |
74c3cbe3 AV |
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; | |
2096f759 | 714 | struct path path1, path2; |
74c3cbe3 | 715 | struct vfsmount *tagged; |
74c3cbe3 AV |
716 | int err; |
717 | ||
2096f759 | 718 | err = kern_path(new, 0, &path2); |
74c3cbe3 AV |
719 | if (err) |
720 | return err; | |
2096f759 AV |
721 | tagged = collect_mounts(&path2); |
722 | path_put(&path2); | |
74c3cbe3 AV |
723 | if (!tagged) |
724 | return -ENOMEM; | |
725 | ||
2096f759 | 726 | err = kern_path(old, 0, &path1); |
74c3cbe3 AV |
727 | if (err) { |
728 | drop_collected_mounts(tagged); | |
729 | return err; | |
730 | } | |
74c3cbe3 | 731 | |
74c3cbe3 AV |
732 | mutex_lock(&audit_filter_mutex); |
733 | list_add(&barrier, &tree_list); | |
734 | list_add(&cursor, &barrier); | |
735 | ||
736 | while (cursor.next != &tree_list) { | |
737 | struct audit_tree *tree; | |
2096f759 | 738 | int good_one = 0; |
74c3cbe3 AV |
739 | |
740 | tree = container_of(cursor.next, struct audit_tree, list); | |
741 | get_tree(tree); | |
742 | list_del(&cursor); | |
743 | list_add(&cursor, &tree->list); | |
744 | mutex_unlock(&audit_filter_mutex); | |
745 | ||
2096f759 AV |
746 | err = kern_path(tree->pathname, 0, &path2); |
747 | if (!err) { | |
748 | good_one = path_is_under(&path1, &path2); | |
749 | path_put(&path2); | |
74c3cbe3 AV |
750 | } |
751 | ||
2096f759 | 752 | if (!good_one) { |
74c3cbe3 AV |
753 | put_tree(tree); |
754 | mutex_lock(&audit_filter_mutex); | |
755 | continue; | |
756 | } | |
74c3cbe3 | 757 | |
1f707137 | 758 | failed = iterate_mounts(tag_mount, tree, tagged); |
74c3cbe3 AV |
759 | if (failed) { |
760 | put_tree(tree); | |
761 | mutex_lock(&audit_filter_mutex); | |
762 | break; | |
763 | } | |
764 | ||
765 | mutex_lock(&audit_filter_mutex); | |
766 | spin_lock(&hash_lock); | |
767 | if (!tree->goner) { | |
768 | list_del(&tree->list); | |
769 | list_add(&tree->list, &tree_list); | |
770 | } | |
771 | spin_unlock(&hash_lock); | |
772 | put_tree(tree); | |
773 | } | |
774 | ||
775 | while (barrier.prev != &tree_list) { | |
776 | struct audit_tree *tree; | |
777 | ||
778 | tree = container_of(barrier.prev, struct audit_tree, list); | |
779 | get_tree(tree); | |
780 | list_del(&tree->list); | |
781 | list_add(&tree->list, &barrier); | |
782 | mutex_unlock(&audit_filter_mutex); | |
783 | ||
784 | if (!failed) { | |
785 | struct node *node; | |
786 | spin_lock(&hash_lock); | |
787 | list_for_each_entry(node, &tree->chunks, list) | |
788 | node->index &= ~(1U<<31); | |
789 | spin_unlock(&hash_lock); | |
790 | } else { | |
791 | trim_marked(tree); | |
792 | } | |
793 | ||
794 | put_tree(tree); | |
795 | mutex_lock(&audit_filter_mutex); | |
796 | } | |
797 | list_del(&barrier); | |
798 | list_del(&cursor); | |
74c3cbe3 | 799 | mutex_unlock(&audit_filter_mutex); |
2096f759 | 800 | path_put(&path1); |
74c3cbe3 AV |
801 | drop_collected_mounts(tagged); |
802 | return failed; | |
803 | } | |
804 | ||
805 | /* | |
806 | * That gets run when evict_chunk() ends up needing to kill audit_tree. | |
916d7576 | 807 | * Runs from a separate thread. |
74c3cbe3 | 808 | */ |
916d7576 | 809 | static int prune_tree_thread(void *unused) |
74c3cbe3 | 810 | { |
916d7576 | 811 | mutex_lock(&audit_cmd_mutex); |
74c3cbe3 AV |
812 | mutex_lock(&audit_filter_mutex); |
813 | ||
814 | while (!list_empty(&prune_list)) { | |
815 | struct audit_tree *victim; | |
816 | ||
817 | victim = list_entry(prune_list.next, struct audit_tree, list); | |
818 | list_del_init(&victim->list); | |
819 | ||
820 | mutex_unlock(&audit_filter_mutex); | |
821 | ||
822 | prune_one(victim); | |
823 | ||
824 | mutex_lock(&audit_filter_mutex); | |
825 | } | |
826 | ||
827 | mutex_unlock(&audit_filter_mutex); | |
916d7576 AV |
828 | mutex_unlock(&audit_cmd_mutex); |
829 | return 0; | |
830 | } | |
831 | ||
832 | static void audit_schedule_prune(void) | |
833 | { | |
834 | kthread_run(prune_tree_thread, NULL, "audit_prune_tree"); | |
835 | } | |
836 | ||
837 | /* | |
838 | * ... and that one is done if evict_chunk() decides to delay until the end | |
839 | * of syscall. Runs synchronously. | |
840 | */ | |
841 | void audit_kill_trees(struct list_head *list) | |
842 | { | |
843 | mutex_lock(&audit_cmd_mutex); | |
844 | mutex_lock(&audit_filter_mutex); | |
845 | ||
846 | while (!list_empty(list)) { | |
847 | struct audit_tree *victim; | |
848 | ||
849 | victim = list_entry(list->next, struct audit_tree, list); | |
850 | kill_rules(victim); | |
851 | list_del_init(&victim->list); | |
852 | ||
853 | mutex_unlock(&audit_filter_mutex); | |
854 | ||
855 | prune_one(victim); | |
856 | ||
857 | mutex_lock(&audit_filter_mutex); | |
858 | } | |
859 | ||
860 | mutex_unlock(&audit_filter_mutex); | |
861 | mutex_unlock(&audit_cmd_mutex); | |
74c3cbe3 AV |
862 | } |
863 | ||
864 | /* | |
865 | * Here comes the stuff asynchronous to auditctl operations | |
866 | */ | |
867 | ||
74c3cbe3 AV |
868 | static void evict_chunk(struct audit_chunk *chunk) |
869 | { | |
870 | struct audit_tree *owner; | |
916d7576 AV |
871 | struct list_head *postponed = audit_killed_trees(); |
872 | int need_prune = 0; | |
74c3cbe3 AV |
873 | int n; |
874 | ||
875 | if (chunk->dead) | |
876 | return; | |
877 | ||
878 | chunk->dead = 1; | |
879 | mutex_lock(&audit_filter_mutex); | |
880 | spin_lock(&hash_lock); | |
881 | while (!list_empty(&chunk->trees)) { | |
882 | owner = list_entry(chunk->trees.next, | |
883 | struct audit_tree, same_root); | |
884 | owner->goner = 1; | |
885 | owner->root = NULL; | |
886 | list_del_init(&owner->same_root); | |
887 | spin_unlock(&hash_lock); | |
916d7576 AV |
888 | if (!postponed) { |
889 | kill_rules(owner); | |
890 | list_move(&owner->list, &prune_list); | |
891 | need_prune = 1; | |
892 | } else { | |
893 | list_move(&owner->list, postponed); | |
894 | } | |
74c3cbe3 AV |
895 | spin_lock(&hash_lock); |
896 | } | |
897 | list_del_rcu(&chunk->hash); | |
898 | for (n = 0; n < chunk->count; n++) | |
899 | list_del_init(&chunk->owners[n].list); | |
900 | spin_unlock(&hash_lock); | |
916d7576 AV |
901 | if (need_prune) |
902 | audit_schedule_prune(); | |
74c3cbe3 AV |
903 | mutex_unlock(&audit_filter_mutex); |
904 | } | |
905 | ||
3a9b16b4 | 906 | static int audit_tree_handle_event(struct fsnotify_group *group, |
ce8f76fb EP |
907 | struct fsnotify_mark *inode_mark, |
908 | struct fsnotify_mark *vfsmonut_mark, | |
3a9b16b4 | 909 | struct fsnotify_event *event) |
74c3cbe3 | 910 | { |
28a3a7eb EP |
911 | BUG(); |
912 | return -EOPNOTSUPP; | |
913 | } | |
74c3cbe3 | 914 | |
e61ce867 | 915 | static void audit_tree_freeing_mark(struct fsnotify_mark *entry, struct fsnotify_group *group) |
28a3a7eb EP |
916 | { |
917 | struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark); | |
918 | ||
919 | evict_chunk(chunk); | |
920 | fsnotify_put_mark(entry); | |
74c3cbe3 AV |
921 | } |
922 | ||
7b0a04fb | 923 | static bool audit_tree_send_event(struct fsnotify_group *group, struct inode *inode, |
1968f5ee | 924 | struct fsnotify_mark *inode_mark, |
ce8f76fb | 925 | struct fsnotify_mark *vfsmount_mark, |
3a9b16b4 | 926 | __u32 mask, void *data, int data_type) |
74c3cbe3 | 927 | { |
2612abb5 | 928 | return false; |
74c3cbe3 AV |
929 | } |
930 | ||
28a3a7eb EP |
931 | static const struct fsnotify_ops audit_tree_ops = { |
932 | .handle_event = audit_tree_handle_event, | |
933 | .should_send_event = audit_tree_send_event, | |
934 | .free_group_priv = NULL, | |
935 | .free_event_priv = NULL, | |
936 | .freeing_mark = audit_tree_freeing_mark, | |
74c3cbe3 AV |
937 | }; |
938 | ||
939 | static int __init audit_tree_init(void) | |
940 | { | |
941 | int i; | |
942 | ||
0d2e2a1d | 943 | audit_tree_group = fsnotify_alloc_group(&audit_tree_ops); |
28a3a7eb EP |
944 | if (IS_ERR(audit_tree_group)) |
945 | audit_panic("cannot initialize fsnotify group for rectree watches"); | |
74c3cbe3 AV |
946 | |
947 | for (i = 0; i < HASH_SIZE; i++) | |
948 | INIT_LIST_HEAD(&chunk_hash_heads[i]); | |
949 | ||
950 | return 0; | |
951 | } | |
952 | __initcall(audit_tree_init); |