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); | |
f1aaf262 | 40 | static struct task_struct *prune_thread; |
74c3cbe3 AV |
41 | |
42 | /* | |
43 | * One struct chunk is attached to each inode of interest. | |
44 | * We replace struct chunk on tagging/untagging. | |
45 | * Rules have pointer to struct audit_tree. | |
46 | * Rules have struct list_head rlist forming a list of rules over | |
47 | * the same tree. | |
48 | * References to struct chunk are collected at audit_inode{,_child}() | |
49 | * time and used in AUDIT_TREE rule matching. | |
50 | * These references are dropped at the same time we are calling | |
51 | * audit_free_names(), etc. | |
52 | * | |
53 | * Cyclic lists galore: | |
54 | * tree.chunks anchors chunk.owners[].list hash_lock | |
55 | * tree.rules anchors rule.rlist audit_filter_mutex | |
56 | * chunk.trees anchors tree.same_root hash_lock | |
57 | * chunk.hash is a hash with middle bits of watch.inode as | |
58 | * a hash function. RCU, hash_lock | |
59 | * | |
60 | * tree is refcounted; one reference for "some rules on rules_list refer to | |
61 | * it", one for each chunk with pointer to it. | |
62 | * | |
28a3a7eb | 63 | * chunk is refcounted by embedded fsnotify_mark + .refs (non-zero refcount |
8f7b0ba1 | 64 | * of watch contributes 1 to .refs). |
74c3cbe3 AV |
65 | * |
66 | * node.index allows to get from node.list to containing chunk. | |
67 | * MSB of that sucker is stolen to mark taggings that we might have to | |
68 | * revert - several operations have very unpleasant cleanup logics and | |
69 | * that makes a difference. Some. | |
70 | */ | |
71 | ||
28a3a7eb | 72 | static struct fsnotify_group *audit_tree_group; |
74c3cbe3 AV |
73 | |
74 | static struct audit_tree *alloc_tree(const char *s) | |
75 | { | |
76 | struct audit_tree *tree; | |
77 | ||
78 | tree = kmalloc(sizeof(struct audit_tree) + strlen(s) + 1, GFP_KERNEL); | |
79 | if (tree) { | |
80 | atomic_set(&tree->count, 1); | |
81 | tree->goner = 0; | |
82 | INIT_LIST_HEAD(&tree->chunks); | |
83 | INIT_LIST_HEAD(&tree->rules); | |
84 | INIT_LIST_HEAD(&tree->list); | |
85 | INIT_LIST_HEAD(&tree->same_root); | |
86 | tree->root = NULL; | |
87 | strcpy(tree->pathname, s); | |
88 | } | |
89 | return tree; | |
90 | } | |
91 | ||
92 | static inline void get_tree(struct audit_tree *tree) | |
93 | { | |
94 | atomic_inc(&tree->count); | |
95 | } | |
96 | ||
74c3cbe3 AV |
97 | static inline void put_tree(struct audit_tree *tree) |
98 | { | |
99 | if (atomic_dec_and_test(&tree->count)) | |
3b097c46 | 100 | kfree_rcu(tree, head); |
74c3cbe3 AV |
101 | } |
102 | ||
103 | /* to avoid bringing the entire thing in audit.h */ | |
104 | const char *audit_tree_path(struct audit_tree *tree) | |
105 | { | |
106 | return tree->pathname; | |
107 | } | |
108 | ||
8f7b0ba1 | 109 | static void free_chunk(struct audit_chunk *chunk) |
74c3cbe3 | 110 | { |
74c3cbe3 AV |
111 | int i; |
112 | ||
113 | for (i = 0; i < chunk->count; i++) { | |
114 | if (chunk->owners[i].owner) | |
115 | put_tree(chunk->owners[i].owner); | |
116 | } | |
117 | kfree(chunk); | |
118 | } | |
119 | ||
8f7b0ba1 | 120 | void audit_put_chunk(struct audit_chunk *chunk) |
74c3cbe3 | 121 | { |
8f7b0ba1 AV |
122 | if (atomic_long_dec_and_test(&chunk->refs)) |
123 | free_chunk(chunk); | |
74c3cbe3 AV |
124 | } |
125 | ||
8f7b0ba1 | 126 | static void __put_chunk(struct rcu_head *rcu) |
74c3cbe3 | 127 | { |
8f7b0ba1 AV |
128 | struct audit_chunk *chunk = container_of(rcu, struct audit_chunk, head); |
129 | audit_put_chunk(chunk); | |
74c3cbe3 AV |
130 | } |
131 | ||
e61ce867 | 132 | static void audit_tree_destroy_watch(struct fsnotify_mark *entry) |
28a3a7eb EP |
133 | { |
134 | struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark); | |
135 | call_rcu(&chunk->head, __put_chunk); | |
136 | } | |
137 | ||
138 | static struct audit_chunk *alloc_chunk(int count) | |
139 | { | |
140 | struct audit_chunk *chunk; | |
141 | size_t size; | |
142 | int i; | |
143 | ||
144 | size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node); | |
145 | chunk = kzalloc(size, GFP_KERNEL); | |
146 | if (!chunk) | |
147 | return NULL; | |
148 | ||
149 | INIT_LIST_HEAD(&chunk->hash); | |
150 | INIT_LIST_HEAD(&chunk->trees); | |
151 | chunk->count = count; | |
152 | atomic_long_set(&chunk->refs, 1); | |
153 | for (i = 0; i < count; i++) { | |
154 | INIT_LIST_HEAD(&chunk->owners[i].list); | |
155 | chunk->owners[i].index = i; | |
156 | } | |
157 | fsnotify_init_mark(&chunk->mark, audit_tree_destroy_watch); | |
799b6014 | 158 | chunk->mark.mask = FS_IN_IGNORED; |
28a3a7eb EP |
159 | return chunk; |
160 | } | |
161 | ||
74c3cbe3 AV |
162 | enum {HASH_SIZE = 128}; |
163 | static struct list_head chunk_hash_heads[HASH_SIZE]; | |
164 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock); | |
165 | ||
166 | static inline struct list_head *chunk_hash(const struct inode *inode) | |
167 | { | |
168 | unsigned long n = (unsigned long)inode / L1_CACHE_BYTES; | |
169 | return chunk_hash_heads + n % HASH_SIZE; | |
170 | } | |
171 | ||
28a3a7eb | 172 | /* hash_lock & entry->lock is held by caller */ |
74c3cbe3 AV |
173 | static void insert_hash(struct audit_chunk *chunk) |
174 | { | |
e61ce867 | 175 | struct fsnotify_mark *entry = &chunk->mark; |
28a3a7eb EP |
176 | struct list_head *list; |
177 | ||
0809ab69 | 178 | if (!entry->inode) |
28a3a7eb | 179 | return; |
0809ab69 | 180 | list = chunk_hash(entry->inode); |
74c3cbe3 AV |
181 | list_add_rcu(&chunk->hash, list); |
182 | } | |
183 | ||
184 | /* called under rcu_read_lock */ | |
185 | struct audit_chunk *audit_tree_lookup(const struct inode *inode) | |
186 | { | |
187 | struct list_head *list = chunk_hash(inode); | |
6793a051 | 188 | struct audit_chunk *p; |
74c3cbe3 | 189 | |
6793a051 | 190 | list_for_each_entry_rcu(p, list, hash) { |
28a3a7eb | 191 | /* mark.inode may have gone NULL, but who cares? */ |
0809ab69 | 192 | if (p->mark.inode == inode) { |
8f7b0ba1 | 193 | atomic_long_inc(&p->refs); |
74c3cbe3 AV |
194 | return p; |
195 | } | |
196 | } | |
197 | return NULL; | |
198 | } | |
199 | ||
6f1b5d7a | 200 | bool audit_tree_match(struct audit_chunk *chunk, struct audit_tree *tree) |
74c3cbe3 AV |
201 | { |
202 | int n; | |
203 | for (n = 0; n < chunk->count; n++) | |
204 | if (chunk->owners[n].owner == tree) | |
6f1b5d7a YB |
205 | return true; |
206 | return false; | |
74c3cbe3 AV |
207 | } |
208 | ||
209 | /* tagging and untagging inodes with trees */ | |
210 | ||
8f7b0ba1 AV |
211 | static struct audit_chunk *find_chunk(struct node *p) |
212 | { | |
213 | int index = p->index & ~(1U<<31); | |
214 | p -= index; | |
215 | return container_of(p, struct audit_chunk, owners[0]); | |
216 | } | |
217 | ||
218 | static void untag_chunk(struct node *p) | |
74c3cbe3 | 219 | { |
8f7b0ba1 | 220 | struct audit_chunk *chunk = find_chunk(p); |
e61ce867 | 221 | struct fsnotify_mark *entry = &chunk->mark; |
f7a998a9 | 222 | struct audit_chunk *new = NULL; |
74c3cbe3 AV |
223 | struct audit_tree *owner; |
224 | int size = chunk->count - 1; | |
225 | int i, j; | |
226 | ||
28a3a7eb | 227 | fsnotify_get_mark(entry); |
8f7b0ba1 AV |
228 | |
229 | spin_unlock(&hash_lock); | |
230 | ||
f7a998a9 AV |
231 | if (size) |
232 | new = alloc_chunk(size); | |
233 | ||
28a3a7eb | 234 | spin_lock(&entry->lock); |
0809ab69 | 235 | if (chunk->dead || !entry->inode) { |
28a3a7eb | 236 | spin_unlock(&entry->lock); |
f7a998a9 AV |
237 | if (new) |
238 | free_chunk(new); | |
8f7b0ba1 | 239 | goto out; |
74c3cbe3 AV |
240 | } |
241 | ||
242 | owner = p->owner; | |
243 | ||
244 | if (!size) { | |
245 | chunk->dead = 1; | |
246 | spin_lock(&hash_lock); | |
247 | list_del_init(&chunk->trees); | |
248 | if (owner->root == chunk) | |
249 | owner->root = NULL; | |
250 | list_del_init(&p->list); | |
251 | list_del_rcu(&chunk->hash); | |
252 | spin_unlock(&hash_lock); | |
28a3a7eb | 253 | spin_unlock(&entry->lock); |
e2a29943 | 254 | fsnotify_destroy_mark(entry, audit_tree_group); |
8f7b0ba1 | 255 | goto out; |
74c3cbe3 AV |
256 | } |
257 | ||
74c3cbe3 AV |
258 | if (!new) |
259 | goto Fallback; | |
f7a998a9 | 260 | |
28a3a7eb | 261 | fsnotify_duplicate_mark(&new->mark, entry); |
0809ab69 | 262 | if (fsnotify_add_mark(&new->mark, new->mark.group, new->mark.inode, NULL, 1)) { |
0fe33aae | 263 | fsnotify_put_mark(&new->mark); |
74c3cbe3 AV |
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); |
e2a29943 | 296 | fsnotify_destroy_mark(entry, audit_tree_group); |
b3e8692b | 297 | fsnotify_put_mark(&new->mark); /* drop initial reference */ |
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)) { |
0fe33aae | 326 | fsnotify_put_mark(entry); |
74c3cbe3 AV |
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); |
e2a29943 | 336 | fsnotify_destroy_mark(entry, audit_tree_group); |
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); |
b3e8692b | 351 | fsnotify_put_mark(entry); /* drop initial reference */ |
74c3cbe3 AV |
352 | return 0; |
353 | } | |
354 | ||
355 | /* the first tagged inode becomes root of tree */ | |
356 | static int tag_chunk(struct inode *inode, struct audit_tree *tree) | |
357 | { | |
e61ce867 | 358 | struct fsnotify_mark *old_entry, *chunk_entry; |
74c3cbe3 AV |
359 | struct audit_tree *owner; |
360 | struct audit_chunk *chunk, *old; | |
361 | struct node *p; | |
362 | int n; | |
363 | ||
5444e298 | 364 | old_entry = fsnotify_find_inode_mark(audit_tree_group, inode); |
28a3a7eb | 365 | if (!old_entry) |
74c3cbe3 AV |
366 | return create_chunk(inode, tree); |
367 | ||
28a3a7eb | 368 | old = container_of(old_entry, struct audit_chunk, mark); |
74c3cbe3 AV |
369 | |
370 | /* are we already there? */ | |
371 | spin_lock(&hash_lock); | |
372 | for (n = 0; n < old->count; n++) { | |
373 | if (old->owners[n].owner == tree) { | |
374 | spin_unlock(&hash_lock); | |
28a3a7eb | 375 | fsnotify_put_mark(old_entry); |
74c3cbe3 AV |
376 | return 0; |
377 | } | |
378 | } | |
379 | spin_unlock(&hash_lock); | |
380 | ||
381 | chunk = alloc_chunk(old->count + 1); | |
b4c30aad | 382 | if (!chunk) { |
28a3a7eb | 383 | fsnotify_put_mark(old_entry); |
74c3cbe3 | 384 | return -ENOMEM; |
b4c30aad | 385 | } |
74c3cbe3 | 386 | |
28a3a7eb EP |
387 | chunk_entry = &chunk->mark; |
388 | ||
389 | spin_lock(&old_entry->lock); | |
0809ab69 | 390 | if (!old_entry->inode) { |
28a3a7eb EP |
391 | /* old_entry is being shot, lets just lie */ |
392 | spin_unlock(&old_entry->lock); | |
393 | fsnotify_put_mark(old_entry); | |
74c3cbe3 | 394 | free_chunk(chunk); |
28a3a7eb EP |
395 | return -ENOENT; |
396 | } | |
397 | ||
398 | fsnotify_duplicate_mark(chunk_entry, old_entry); | |
0809ab69 | 399 | if (fsnotify_add_mark(chunk_entry, chunk_entry->group, chunk_entry->inode, NULL, 1)) { |
28a3a7eb | 400 | spin_unlock(&old_entry->lock); |
0fe33aae | 401 | fsnotify_put_mark(chunk_entry); |
28a3a7eb | 402 | fsnotify_put_mark(old_entry); |
74c3cbe3 AV |
403 | return -ENOSPC; |
404 | } | |
28a3a7eb EP |
405 | |
406 | /* even though we hold old_entry->lock, this is safe since chunk_entry->lock could NEVER have been grabbed before */ | |
407 | spin_lock(&chunk_entry->lock); | |
74c3cbe3 | 408 | spin_lock(&hash_lock); |
28a3a7eb EP |
409 | |
410 | /* we now hold old_entry->lock, chunk_entry->lock, and hash_lock */ | |
74c3cbe3 AV |
411 | if (tree->goner) { |
412 | spin_unlock(&hash_lock); | |
413 | chunk->dead = 1; | |
28a3a7eb EP |
414 | spin_unlock(&chunk_entry->lock); |
415 | spin_unlock(&old_entry->lock); | |
416 | ||
e2a29943 | 417 | fsnotify_destroy_mark(chunk_entry, audit_tree_group); |
28a3a7eb EP |
418 | |
419 | fsnotify_put_mark(chunk_entry); | |
420 | fsnotify_put_mark(old_entry); | |
74c3cbe3 AV |
421 | return 0; |
422 | } | |
423 | list_replace_init(&old->trees, &chunk->trees); | |
424 | for (n = 0, p = chunk->owners; n < old->count; n++, p++) { | |
425 | struct audit_tree *s = old->owners[n].owner; | |
426 | p->owner = s; | |
427 | p->index = old->owners[n].index; | |
428 | if (!s) /* result of fallback in untag */ | |
429 | continue; | |
430 | get_tree(s); | |
431 | list_replace_init(&old->owners[n].list, &p->list); | |
432 | } | |
433 | p->index = (chunk->count - 1) | (1U<<31); | |
434 | p->owner = tree; | |
435 | get_tree(tree); | |
436 | list_add(&p->list, &tree->chunks); | |
437 | list_replace_rcu(&old->hash, &chunk->hash); | |
438 | list_for_each_entry(owner, &chunk->trees, same_root) | |
439 | owner->root = chunk; | |
440 | old->dead = 1; | |
441 | if (!tree->root) { | |
442 | tree->root = chunk; | |
443 | list_add(&tree->same_root, &chunk->trees); | |
444 | } | |
445 | spin_unlock(&hash_lock); | |
28a3a7eb EP |
446 | spin_unlock(&chunk_entry->lock); |
447 | spin_unlock(&old_entry->lock); | |
e2a29943 | 448 | fsnotify_destroy_mark(old_entry, audit_tree_group); |
b3e8692b | 449 | fsnotify_put_mark(chunk_entry); /* drop initial reference */ |
28a3a7eb | 450 | fsnotify_put_mark(old_entry); /* pair to fsnotify_find mark_entry */ |
74c3cbe3 AV |
451 | return 0; |
452 | } | |
453 | ||
2991dd2b | 454 | static void audit_tree_log_remove_rule(struct audit_krule *rule) |
0644ec0c KC |
455 | { |
456 | struct audit_buffer *ab; | |
457 | ||
458 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); | |
459 | if (unlikely(!ab)) | |
460 | return; | |
c1e8f06d | 461 | audit_log_format(ab, "op=remove_rule"); |
0644ec0c KC |
462 | audit_log_format(ab, " dir="); |
463 | audit_log_untrustedstring(ab, rule->tree->pathname); | |
464 | audit_log_key(ab, rule->filterkey); | |
465 | audit_log_format(ab, " list=%d res=1", rule->listnr); | |
466 | audit_log_end(ab); | |
467 | } | |
468 | ||
74c3cbe3 AV |
469 | static void kill_rules(struct audit_tree *tree) |
470 | { | |
471 | struct audit_krule *rule, *next; | |
472 | struct audit_entry *entry; | |
74c3cbe3 AV |
473 | |
474 | list_for_each_entry_safe(rule, next, &tree->rules, rlist) { | |
475 | entry = container_of(rule, struct audit_entry, rule); | |
476 | ||
477 | list_del_init(&rule->rlist); | |
478 | if (rule->tree) { | |
479 | /* not a half-baked one */ | |
2991dd2b | 480 | audit_tree_log_remove_rule(rule); |
34d99af5 RGB |
481 | if (entry->rule.exe) |
482 | audit_remove_mark(entry->rule.exe); | |
74c3cbe3 AV |
483 | rule->tree = NULL; |
484 | list_del_rcu(&entry->list); | |
e45aa212 | 485 | list_del(&entry->rule.list); |
74c3cbe3 AV |
486 | call_rcu(&entry->rcu, audit_free_rule_rcu); |
487 | } | |
488 | } | |
489 | } | |
490 | ||
491 | /* | |
492 | * finish killing struct audit_tree | |
493 | */ | |
494 | static void prune_one(struct audit_tree *victim) | |
495 | { | |
496 | spin_lock(&hash_lock); | |
497 | while (!list_empty(&victim->chunks)) { | |
498 | struct node *p; | |
74c3cbe3 AV |
499 | |
500 | p = list_entry(victim->chunks.next, struct node, list); | |
74c3cbe3 | 501 | |
8f7b0ba1 | 502 | untag_chunk(p); |
74c3cbe3 AV |
503 | } |
504 | spin_unlock(&hash_lock); | |
505 | put_tree(victim); | |
506 | } | |
507 | ||
508 | /* trim the uncommitted chunks from tree */ | |
509 | ||
510 | static void trim_marked(struct audit_tree *tree) | |
511 | { | |
512 | struct list_head *p, *q; | |
513 | spin_lock(&hash_lock); | |
514 | if (tree->goner) { | |
515 | spin_unlock(&hash_lock); | |
516 | return; | |
517 | } | |
518 | /* reorder */ | |
519 | for (p = tree->chunks.next; p != &tree->chunks; p = q) { | |
520 | struct node *node = list_entry(p, struct node, list); | |
521 | q = p->next; | |
522 | if (node->index & (1U<<31)) { | |
523 | list_del_init(p); | |
524 | list_add(p, &tree->chunks); | |
525 | } | |
526 | } | |
527 | ||
528 | while (!list_empty(&tree->chunks)) { | |
529 | struct node *node; | |
74c3cbe3 AV |
530 | |
531 | node = list_entry(tree->chunks.next, struct node, list); | |
532 | ||
533 | /* have we run out of marked? */ | |
534 | if (!(node->index & (1U<<31))) | |
535 | break; | |
536 | ||
8f7b0ba1 | 537 | untag_chunk(node); |
74c3cbe3 AV |
538 | } |
539 | if (!tree->root && !tree->goner) { | |
540 | tree->goner = 1; | |
541 | spin_unlock(&hash_lock); | |
542 | mutex_lock(&audit_filter_mutex); | |
543 | kill_rules(tree); | |
544 | list_del_init(&tree->list); | |
545 | mutex_unlock(&audit_filter_mutex); | |
546 | prune_one(tree); | |
547 | } else { | |
548 | spin_unlock(&hash_lock); | |
549 | } | |
550 | } | |
551 | ||
916d7576 AV |
552 | static void audit_schedule_prune(void); |
553 | ||
74c3cbe3 AV |
554 | /* called with audit_filter_mutex */ |
555 | int audit_remove_tree_rule(struct audit_krule *rule) | |
556 | { | |
557 | struct audit_tree *tree; | |
558 | tree = rule->tree; | |
559 | if (tree) { | |
560 | spin_lock(&hash_lock); | |
561 | list_del_init(&rule->rlist); | |
562 | if (list_empty(&tree->rules) && !tree->goner) { | |
563 | tree->root = NULL; | |
564 | list_del_init(&tree->same_root); | |
565 | tree->goner = 1; | |
566 | list_move(&tree->list, &prune_list); | |
567 | rule->tree = NULL; | |
568 | spin_unlock(&hash_lock); | |
569 | audit_schedule_prune(); | |
570 | return 1; | |
571 | } | |
572 | rule->tree = NULL; | |
573 | spin_unlock(&hash_lock); | |
574 | return 1; | |
575 | } | |
576 | return 0; | |
577 | } | |
578 | ||
1f707137 AV |
579 | static int compare_root(struct vfsmount *mnt, void *arg) |
580 | { | |
3b362157 | 581 | return d_backing_inode(mnt->mnt_root) == arg; |
1f707137 AV |
582 | } |
583 | ||
74c3cbe3 AV |
584 | void audit_trim_trees(void) |
585 | { | |
586 | struct list_head cursor; | |
587 | ||
588 | mutex_lock(&audit_filter_mutex); | |
589 | list_add(&cursor, &tree_list); | |
590 | while (cursor.next != &tree_list) { | |
591 | struct audit_tree *tree; | |
98bc993f | 592 | struct path path; |
74c3cbe3 AV |
593 | struct vfsmount *root_mnt; |
594 | struct node *node; | |
74c3cbe3 AV |
595 | int err; |
596 | ||
597 | tree = container_of(cursor.next, struct audit_tree, list); | |
598 | get_tree(tree); | |
599 | list_del(&cursor); | |
600 | list_add(&cursor, &tree->list); | |
601 | mutex_unlock(&audit_filter_mutex); | |
602 | ||
98bc993f | 603 | err = kern_path(tree->pathname, 0, &path); |
74c3cbe3 AV |
604 | if (err) |
605 | goto skip_it; | |
606 | ||
589ff870 | 607 | root_mnt = collect_mounts(&path); |
98bc993f | 608 | path_put(&path); |
be34d1a3 | 609 | if (IS_ERR(root_mnt)) |
74c3cbe3 AV |
610 | goto skip_it; |
611 | ||
74c3cbe3 AV |
612 | spin_lock(&hash_lock); |
613 | list_for_each_entry(node, &tree->chunks, list) { | |
28a3a7eb | 614 | struct audit_chunk *chunk = find_chunk(node); |
25985edc | 615 | /* this could be NULL if the watch is dying else where... */ |
0809ab69 | 616 | struct inode *inode = chunk->mark.inode; |
74c3cbe3 | 617 | node->index |= 1U<<31; |
1f707137 AV |
618 | if (iterate_mounts(compare_root, inode, root_mnt)) |
619 | node->index &= ~(1U<<31); | |
74c3cbe3 AV |
620 | } |
621 | spin_unlock(&hash_lock); | |
622 | trim_marked(tree); | |
74c3cbe3 AV |
623 | drop_collected_mounts(root_mnt); |
624 | skip_it: | |
12b2f117 | 625 | put_tree(tree); |
74c3cbe3 AV |
626 | mutex_lock(&audit_filter_mutex); |
627 | } | |
628 | list_del(&cursor); | |
629 | mutex_unlock(&audit_filter_mutex); | |
630 | } | |
631 | ||
74c3cbe3 AV |
632 | int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op) |
633 | { | |
634 | ||
635 | if (pathname[0] != '/' || | |
636 | rule->listnr != AUDIT_FILTER_EXIT || | |
5af75d8d | 637 | op != Audit_equal || |
74c3cbe3 AV |
638 | rule->inode_f || rule->watch || rule->tree) |
639 | return -EINVAL; | |
640 | rule->tree = alloc_tree(pathname); | |
641 | if (!rule->tree) | |
642 | return -ENOMEM; | |
643 | return 0; | |
644 | } | |
645 | ||
646 | void audit_put_tree(struct audit_tree *tree) | |
647 | { | |
648 | put_tree(tree); | |
649 | } | |
650 | ||
1f707137 AV |
651 | static int tag_mount(struct vfsmount *mnt, void *arg) |
652 | { | |
3b362157 | 653 | return tag_chunk(d_backing_inode(mnt->mnt_root), arg); |
1f707137 AV |
654 | } |
655 | ||
f1aaf262 IP |
656 | /* |
657 | * That gets run when evict_chunk() ends up needing to kill audit_tree. | |
658 | * Runs from a separate thread. | |
659 | */ | |
660 | static int prune_tree_thread(void *unused) | |
661 | { | |
662 | for (;;) { | |
0bf676d1 JS |
663 | if (list_empty(&prune_list)) { |
664 | set_current_state(TASK_INTERRUPTIBLE); | |
f1aaf262 | 665 | schedule(); |
0bf676d1 | 666 | } |
f1aaf262 IP |
667 | |
668 | mutex_lock(&audit_cmd_mutex); | |
669 | mutex_lock(&audit_filter_mutex); | |
670 | ||
671 | while (!list_empty(&prune_list)) { | |
672 | struct audit_tree *victim; | |
673 | ||
674 | victim = list_entry(prune_list.next, | |
675 | struct audit_tree, list); | |
676 | list_del_init(&victim->list); | |
677 | ||
678 | mutex_unlock(&audit_filter_mutex); | |
679 | ||
680 | prune_one(victim); | |
681 | ||
682 | mutex_lock(&audit_filter_mutex); | |
683 | } | |
684 | ||
685 | mutex_unlock(&audit_filter_mutex); | |
686 | mutex_unlock(&audit_cmd_mutex); | |
687 | } | |
688 | return 0; | |
689 | } | |
690 | ||
691 | static int audit_launch_prune(void) | |
692 | { | |
693 | if (prune_thread) | |
694 | return 0; | |
0bf676d1 | 695 | prune_thread = kthread_run(prune_tree_thread, NULL, |
f1aaf262 IP |
696 | "audit_prune_tree"); |
697 | if (IS_ERR(prune_thread)) { | |
698 | pr_err("cannot start thread audit_prune_tree"); | |
699 | prune_thread = NULL; | |
700 | return -ENOMEM; | |
f1aaf262 | 701 | } |
0bf676d1 | 702 | return 0; |
f1aaf262 IP |
703 | } |
704 | ||
74c3cbe3 AV |
705 | /* called with audit_filter_mutex */ |
706 | int audit_add_tree_rule(struct audit_krule *rule) | |
707 | { | |
708 | struct audit_tree *seed = rule->tree, *tree; | |
98bc993f | 709 | struct path path; |
1f707137 | 710 | struct vfsmount *mnt; |
74c3cbe3 AV |
711 | int err; |
712 | ||
736f3203 | 713 | rule->tree = NULL; |
74c3cbe3 AV |
714 | list_for_each_entry(tree, &tree_list, list) { |
715 | if (!strcmp(seed->pathname, tree->pathname)) { | |
716 | put_tree(seed); | |
717 | rule->tree = tree; | |
718 | list_add(&rule->rlist, &tree->rules); | |
719 | return 0; | |
720 | } | |
721 | } | |
722 | tree = seed; | |
723 | list_add(&tree->list, &tree_list); | |
724 | list_add(&rule->rlist, &tree->rules); | |
725 | /* do not set rule->tree yet */ | |
726 | mutex_unlock(&audit_filter_mutex); | |
727 | ||
f1aaf262 IP |
728 | if (unlikely(!prune_thread)) { |
729 | err = audit_launch_prune(); | |
730 | if (err) | |
731 | goto Err; | |
732 | } | |
733 | ||
98bc993f | 734 | err = kern_path(tree->pathname, 0, &path); |
74c3cbe3 AV |
735 | if (err) |
736 | goto Err; | |
589ff870 | 737 | mnt = collect_mounts(&path); |
98bc993f | 738 | path_put(&path); |
be34d1a3 DH |
739 | if (IS_ERR(mnt)) { |
740 | err = PTR_ERR(mnt); | |
74c3cbe3 AV |
741 | goto Err; |
742 | } | |
74c3cbe3 AV |
743 | |
744 | get_tree(tree); | |
1f707137 | 745 | err = iterate_mounts(tag_mount, tree, mnt); |
74c3cbe3 AV |
746 | drop_collected_mounts(mnt); |
747 | ||
748 | if (!err) { | |
749 | struct node *node; | |
750 | spin_lock(&hash_lock); | |
751 | list_for_each_entry(node, &tree->chunks, list) | |
752 | node->index &= ~(1U<<31); | |
753 | spin_unlock(&hash_lock); | |
754 | } else { | |
755 | trim_marked(tree); | |
756 | goto Err; | |
757 | } | |
758 | ||
759 | mutex_lock(&audit_filter_mutex); | |
760 | if (list_empty(&rule->rlist)) { | |
761 | put_tree(tree); | |
762 | return -ENOENT; | |
763 | } | |
764 | rule->tree = tree; | |
765 | put_tree(tree); | |
766 | ||
767 | return 0; | |
768 | Err: | |
769 | mutex_lock(&audit_filter_mutex); | |
770 | list_del_init(&tree->list); | |
771 | list_del_init(&tree->rules); | |
772 | put_tree(tree); | |
773 | return err; | |
774 | } | |
775 | ||
776 | int audit_tag_tree(char *old, char *new) | |
777 | { | |
778 | struct list_head cursor, barrier; | |
779 | int failed = 0; | |
2096f759 | 780 | struct path path1, path2; |
74c3cbe3 | 781 | struct vfsmount *tagged; |
74c3cbe3 AV |
782 | int err; |
783 | ||
2096f759 | 784 | err = kern_path(new, 0, &path2); |
74c3cbe3 AV |
785 | if (err) |
786 | return err; | |
2096f759 AV |
787 | tagged = collect_mounts(&path2); |
788 | path_put(&path2); | |
be34d1a3 DH |
789 | if (IS_ERR(tagged)) |
790 | return PTR_ERR(tagged); | |
74c3cbe3 | 791 | |
2096f759 | 792 | err = kern_path(old, 0, &path1); |
74c3cbe3 AV |
793 | if (err) { |
794 | drop_collected_mounts(tagged); | |
795 | return err; | |
796 | } | |
74c3cbe3 | 797 | |
74c3cbe3 AV |
798 | mutex_lock(&audit_filter_mutex); |
799 | list_add(&barrier, &tree_list); | |
800 | list_add(&cursor, &barrier); | |
801 | ||
802 | while (cursor.next != &tree_list) { | |
803 | struct audit_tree *tree; | |
2096f759 | 804 | int good_one = 0; |
74c3cbe3 AV |
805 | |
806 | tree = container_of(cursor.next, struct audit_tree, list); | |
807 | get_tree(tree); | |
808 | list_del(&cursor); | |
809 | list_add(&cursor, &tree->list); | |
810 | mutex_unlock(&audit_filter_mutex); | |
811 | ||
2096f759 AV |
812 | err = kern_path(tree->pathname, 0, &path2); |
813 | if (!err) { | |
814 | good_one = path_is_under(&path1, &path2); | |
815 | path_put(&path2); | |
74c3cbe3 AV |
816 | } |
817 | ||
2096f759 | 818 | if (!good_one) { |
74c3cbe3 AV |
819 | put_tree(tree); |
820 | mutex_lock(&audit_filter_mutex); | |
821 | continue; | |
822 | } | |
74c3cbe3 | 823 | |
1f707137 | 824 | failed = iterate_mounts(tag_mount, tree, tagged); |
74c3cbe3 AV |
825 | if (failed) { |
826 | put_tree(tree); | |
827 | mutex_lock(&audit_filter_mutex); | |
828 | break; | |
829 | } | |
830 | ||
831 | mutex_lock(&audit_filter_mutex); | |
832 | spin_lock(&hash_lock); | |
833 | if (!tree->goner) { | |
834 | list_del(&tree->list); | |
835 | list_add(&tree->list, &tree_list); | |
836 | } | |
837 | spin_unlock(&hash_lock); | |
838 | put_tree(tree); | |
839 | } | |
840 | ||
841 | while (barrier.prev != &tree_list) { | |
842 | struct audit_tree *tree; | |
843 | ||
844 | tree = container_of(barrier.prev, struct audit_tree, list); | |
845 | get_tree(tree); | |
846 | list_del(&tree->list); | |
847 | list_add(&tree->list, &barrier); | |
848 | mutex_unlock(&audit_filter_mutex); | |
849 | ||
850 | if (!failed) { | |
851 | struct node *node; | |
852 | spin_lock(&hash_lock); | |
853 | list_for_each_entry(node, &tree->chunks, list) | |
854 | node->index &= ~(1U<<31); | |
855 | spin_unlock(&hash_lock); | |
856 | } else { | |
857 | trim_marked(tree); | |
858 | } | |
859 | ||
860 | put_tree(tree); | |
861 | mutex_lock(&audit_filter_mutex); | |
862 | } | |
863 | list_del(&barrier); | |
864 | list_del(&cursor); | |
74c3cbe3 | 865 | mutex_unlock(&audit_filter_mutex); |
2096f759 | 866 | path_put(&path1); |
74c3cbe3 AV |
867 | drop_collected_mounts(tagged); |
868 | return failed; | |
869 | } | |
870 | ||
916d7576 AV |
871 | |
872 | static void audit_schedule_prune(void) | |
873 | { | |
f1aaf262 | 874 | wake_up_process(prune_thread); |
916d7576 AV |
875 | } |
876 | ||
877 | /* | |
878 | * ... and that one is done if evict_chunk() decides to delay until the end | |
879 | * of syscall. Runs synchronously. | |
880 | */ | |
881 | void audit_kill_trees(struct list_head *list) | |
882 | { | |
883 | mutex_lock(&audit_cmd_mutex); | |
884 | mutex_lock(&audit_filter_mutex); | |
885 | ||
886 | while (!list_empty(list)) { | |
887 | struct audit_tree *victim; | |
888 | ||
889 | victim = list_entry(list->next, struct audit_tree, list); | |
890 | kill_rules(victim); | |
891 | list_del_init(&victim->list); | |
892 | ||
893 | mutex_unlock(&audit_filter_mutex); | |
894 | ||
895 | prune_one(victim); | |
896 | ||
897 | mutex_lock(&audit_filter_mutex); | |
898 | } | |
899 | ||
900 | mutex_unlock(&audit_filter_mutex); | |
901 | mutex_unlock(&audit_cmd_mutex); | |
74c3cbe3 AV |
902 | } |
903 | ||
904 | /* | |
905 | * Here comes the stuff asynchronous to auditctl operations | |
906 | */ | |
907 | ||
74c3cbe3 AV |
908 | static void evict_chunk(struct audit_chunk *chunk) |
909 | { | |
910 | struct audit_tree *owner; | |
916d7576 AV |
911 | struct list_head *postponed = audit_killed_trees(); |
912 | int need_prune = 0; | |
74c3cbe3 AV |
913 | int n; |
914 | ||
915 | if (chunk->dead) | |
916 | return; | |
917 | ||
918 | chunk->dead = 1; | |
919 | mutex_lock(&audit_filter_mutex); | |
920 | spin_lock(&hash_lock); | |
921 | while (!list_empty(&chunk->trees)) { | |
922 | owner = list_entry(chunk->trees.next, | |
923 | struct audit_tree, same_root); | |
924 | owner->goner = 1; | |
925 | owner->root = NULL; | |
926 | list_del_init(&owner->same_root); | |
927 | spin_unlock(&hash_lock); | |
916d7576 AV |
928 | if (!postponed) { |
929 | kill_rules(owner); | |
930 | list_move(&owner->list, &prune_list); | |
931 | need_prune = 1; | |
932 | } else { | |
933 | list_move(&owner->list, postponed); | |
934 | } | |
74c3cbe3 AV |
935 | spin_lock(&hash_lock); |
936 | } | |
937 | list_del_rcu(&chunk->hash); | |
938 | for (n = 0; n < chunk->count; n++) | |
939 | list_del_init(&chunk->owners[n].list); | |
940 | spin_unlock(&hash_lock); | |
f1aaf262 | 941 | mutex_unlock(&audit_filter_mutex); |
916d7576 AV |
942 | if (need_prune) |
943 | audit_schedule_prune(); | |
74c3cbe3 AV |
944 | } |
945 | ||
3a9b16b4 | 946 | static int audit_tree_handle_event(struct fsnotify_group *group, |
7053aee2 | 947 | struct inode *to_tell, |
ce8f76fb | 948 | struct fsnotify_mark *inode_mark, |
7053aee2 | 949 | struct fsnotify_mark *vfsmount_mark, |
3cd5eca8 | 950 | u32 mask, const void *data, int data_type, |
45a22f4c | 951 | const unsigned char *file_name, u32 cookie) |
74c3cbe3 | 952 | { |
83c4c4b0 | 953 | return 0; |
28a3a7eb | 954 | } |
74c3cbe3 | 955 | |
e61ce867 | 956 | static void audit_tree_freeing_mark(struct fsnotify_mark *entry, struct fsnotify_group *group) |
28a3a7eb EP |
957 | { |
958 | struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark); | |
959 | ||
960 | evict_chunk(chunk); | |
b3e8692b MS |
961 | |
962 | /* | |
963 | * We are guaranteed to have at least one reference to the mark from | |
964 | * either the inode or the caller of fsnotify_destroy_mark(). | |
965 | */ | |
966 | BUG_ON(atomic_read(&entry->refcnt) < 1); | |
74c3cbe3 AV |
967 | } |
968 | ||
28a3a7eb EP |
969 | static const struct fsnotify_ops audit_tree_ops = { |
970 | .handle_event = audit_tree_handle_event, | |
28a3a7eb | 971 | .freeing_mark = audit_tree_freeing_mark, |
74c3cbe3 AV |
972 | }; |
973 | ||
974 | static int __init audit_tree_init(void) | |
975 | { | |
976 | int i; | |
977 | ||
0d2e2a1d | 978 | audit_tree_group = fsnotify_alloc_group(&audit_tree_ops); |
28a3a7eb EP |
979 | if (IS_ERR(audit_tree_group)) |
980 | audit_panic("cannot initialize fsnotify group for rectree watches"); | |
74c3cbe3 AV |
981 | |
982 | for (i = 0; i < HASH_SIZE; i++) | |
983 | INIT_LIST_HEAD(&chunk_hash_heads[i]); | |
984 | ||
985 | return 0; | |
986 | } | |
987 | __initcall(audit_tree_init); |