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Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
74c3cbe3 | 2 | #include "audit.h" |
28a3a7eb | 3 | #include <linux/fsnotify_backend.h> |
74c3cbe3 AV |
4 | #include <linux/namei.h> |
5 | #include <linux/mount.h> | |
916d7576 | 6 | #include <linux/kthread.h> |
9d2378f8 | 7 | #include <linux/refcount.h> |
5a0e3ad6 | 8 | #include <linux/slab.h> |
74c3cbe3 AV |
9 | |
10 | struct audit_tree; | |
11 | struct audit_chunk; | |
12 | ||
13 | struct audit_tree { | |
9d2378f8 | 14 | refcount_t count; |
74c3cbe3 AV |
15 | int goner; |
16 | struct audit_chunk *root; | |
17 | struct list_head chunks; | |
18 | struct list_head rules; | |
19 | struct list_head list; | |
20 | struct list_head same_root; | |
21 | struct rcu_head head; | |
22 | char pathname[]; | |
23 | }; | |
24 | ||
25 | struct audit_chunk { | |
26 | struct list_head hash; | |
5685d81d | 27 | unsigned long key; |
e61ce867 | 28 | struct fsnotify_mark mark; |
74c3cbe3 AV |
29 | struct list_head trees; /* with root here */ |
30 | int dead; | |
31 | int count; | |
8f7b0ba1 | 32 | atomic_long_t refs; |
74c3cbe3 AV |
33 | struct rcu_head head; |
34 | struct node { | |
35 | struct list_head list; | |
36 | struct audit_tree *owner; | |
37 | unsigned index; /* index; upper bit indicates 'will prune' */ | |
38 | } owners[]; | |
39 | }; | |
40 | ||
41 | static LIST_HEAD(tree_list); | |
42 | static LIST_HEAD(prune_list); | |
f1aaf262 | 43 | static struct task_struct *prune_thread; |
74c3cbe3 AV |
44 | |
45 | /* | |
46 | * One struct chunk is attached to each inode of interest. | |
47 | * We replace struct chunk on tagging/untagging. | |
48 | * Rules have pointer to struct audit_tree. | |
49 | * Rules have struct list_head rlist forming a list of rules over | |
50 | * the same tree. | |
51 | * References to struct chunk are collected at audit_inode{,_child}() | |
52 | * time and used in AUDIT_TREE rule matching. | |
53 | * These references are dropped at the same time we are calling | |
54 | * audit_free_names(), etc. | |
55 | * | |
56 | * Cyclic lists galore: | |
57 | * tree.chunks anchors chunk.owners[].list hash_lock | |
58 | * tree.rules anchors rule.rlist audit_filter_mutex | |
59 | * chunk.trees anchors tree.same_root hash_lock | |
60 | * chunk.hash is a hash with middle bits of watch.inode as | |
61 | * a hash function. RCU, hash_lock | |
62 | * | |
63 | * tree is refcounted; one reference for "some rules on rules_list refer to | |
64 | * it", one for each chunk with pointer to it. | |
65 | * | |
28a3a7eb | 66 | * chunk is refcounted by embedded fsnotify_mark + .refs (non-zero refcount |
8f7b0ba1 | 67 | * of watch contributes 1 to .refs). |
74c3cbe3 AV |
68 | * |
69 | * node.index allows to get from node.list to containing chunk. | |
70 | * MSB of that sucker is stolen to mark taggings that we might have to | |
71 | * revert - several operations have very unpleasant cleanup logics and | |
72 | * that makes a difference. Some. | |
73 | */ | |
74 | ||
28a3a7eb | 75 | static struct fsnotify_group *audit_tree_group; |
74c3cbe3 AV |
76 | |
77 | static struct audit_tree *alloc_tree(const char *s) | |
78 | { | |
79 | struct audit_tree *tree; | |
80 | ||
81 | tree = kmalloc(sizeof(struct audit_tree) + strlen(s) + 1, GFP_KERNEL); | |
82 | if (tree) { | |
9d2378f8 | 83 | refcount_set(&tree->count, 1); |
74c3cbe3 AV |
84 | tree->goner = 0; |
85 | INIT_LIST_HEAD(&tree->chunks); | |
86 | INIT_LIST_HEAD(&tree->rules); | |
87 | INIT_LIST_HEAD(&tree->list); | |
88 | INIT_LIST_HEAD(&tree->same_root); | |
89 | tree->root = NULL; | |
90 | strcpy(tree->pathname, s); | |
91 | } | |
92 | return tree; | |
93 | } | |
94 | ||
95 | static inline void get_tree(struct audit_tree *tree) | |
96 | { | |
9d2378f8 | 97 | refcount_inc(&tree->count); |
74c3cbe3 AV |
98 | } |
99 | ||
74c3cbe3 AV |
100 | static inline void put_tree(struct audit_tree *tree) |
101 | { | |
9d2378f8 | 102 | if (refcount_dec_and_test(&tree->count)) |
3b097c46 | 103 | kfree_rcu(tree, head); |
74c3cbe3 AV |
104 | } |
105 | ||
106 | /* to avoid bringing the entire thing in audit.h */ | |
107 | const char *audit_tree_path(struct audit_tree *tree) | |
108 | { | |
109 | return tree->pathname; | |
110 | } | |
111 | ||
8f7b0ba1 | 112 | static void free_chunk(struct audit_chunk *chunk) |
74c3cbe3 | 113 | { |
74c3cbe3 AV |
114 | int i; |
115 | ||
116 | for (i = 0; i < chunk->count; i++) { | |
117 | if (chunk->owners[i].owner) | |
118 | put_tree(chunk->owners[i].owner); | |
119 | } | |
120 | kfree(chunk); | |
121 | } | |
122 | ||
8f7b0ba1 | 123 | void audit_put_chunk(struct audit_chunk *chunk) |
74c3cbe3 | 124 | { |
8f7b0ba1 AV |
125 | if (atomic_long_dec_and_test(&chunk->refs)) |
126 | free_chunk(chunk); | |
74c3cbe3 AV |
127 | } |
128 | ||
8f7b0ba1 | 129 | static void __put_chunk(struct rcu_head *rcu) |
74c3cbe3 | 130 | { |
8f7b0ba1 AV |
131 | struct audit_chunk *chunk = container_of(rcu, struct audit_chunk, head); |
132 | audit_put_chunk(chunk); | |
74c3cbe3 AV |
133 | } |
134 | ||
e61ce867 | 135 | static void audit_tree_destroy_watch(struct fsnotify_mark *entry) |
28a3a7eb EP |
136 | { |
137 | struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark); | |
138 | call_rcu(&chunk->head, __put_chunk); | |
139 | } | |
140 | ||
141 | static struct audit_chunk *alloc_chunk(int count) | |
142 | { | |
143 | struct audit_chunk *chunk; | |
144 | size_t size; | |
145 | int i; | |
146 | ||
147 | size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node); | |
148 | chunk = kzalloc(size, GFP_KERNEL); | |
149 | if (!chunk) | |
150 | return NULL; | |
151 | ||
152 | INIT_LIST_HEAD(&chunk->hash); | |
153 | INIT_LIST_HEAD(&chunk->trees); | |
154 | chunk->count = count; | |
155 | atomic_long_set(&chunk->refs, 1); | |
156 | for (i = 0; i < count; i++) { | |
157 | INIT_LIST_HEAD(&chunk->owners[i].list); | |
158 | chunk->owners[i].index = i; | |
159 | } | |
054c636e | 160 | fsnotify_init_mark(&chunk->mark, audit_tree_group); |
799b6014 | 161 | chunk->mark.mask = FS_IN_IGNORED; |
28a3a7eb EP |
162 | return chunk; |
163 | } | |
164 | ||
74c3cbe3 AV |
165 | enum {HASH_SIZE = 128}; |
166 | static struct list_head chunk_hash_heads[HASH_SIZE]; | |
167 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock); | |
168 | ||
f410ff65 JK |
169 | /* Function to return search key in our hash from inode. */ |
170 | static unsigned long inode_to_key(const struct inode *inode) | |
74c3cbe3 | 171 | { |
f410ff65 JK |
172 | return (unsigned long)inode; |
173 | } | |
174 | ||
f410ff65 JK |
175 | static inline struct list_head *chunk_hash(unsigned long key) |
176 | { | |
177 | unsigned long n = key / L1_CACHE_BYTES; | |
74c3cbe3 AV |
178 | return chunk_hash_heads + n % HASH_SIZE; |
179 | } | |
180 | ||
28a3a7eb | 181 | /* hash_lock & entry->lock is held by caller */ |
74c3cbe3 AV |
182 | static void insert_hash(struct audit_chunk *chunk) |
183 | { | |
28a3a7eb EP |
184 | struct list_head *list; |
185 | ||
43471d15 | 186 | if (!(chunk->mark.flags & FSNOTIFY_MARK_FLAG_ATTACHED)) |
28a3a7eb | 187 | return; |
5685d81d JK |
188 | WARN_ON_ONCE(!chunk->key); |
189 | list = chunk_hash(chunk->key); | |
74c3cbe3 AV |
190 | list_add_rcu(&chunk->hash, list); |
191 | } | |
192 | ||
193 | /* called under rcu_read_lock */ | |
194 | struct audit_chunk *audit_tree_lookup(const struct inode *inode) | |
195 | { | |
f410ff65 JK |
196 | unsigned long key = inode_to_key(inode); |
197 | struct list_head *list = chunk_hash(key); | |
6793a051 | 198 | struct audit_chunk *p; |
74c3cbe3 | 199 | |
6793a051 | 200 | list_for_each_entry_rcu(p, list, hash) { |
5685d81d | 201 | if (p->key == key) { |
8f7b0ba1 | 202 | atomic_long_inc(&p->refs); |
74c3cbe3 AV |
203 | return p; |
204 | } | |
205 | } | |
206 | return NULL; | |
207 | } | |
208 | ||
6f1b5d7a | 209 | bool audit_tree_match(struct audit_chunk *chunk, struct audit_tree *tree) |
74c3cbe3 AV |
210 | { |
211 | int n; | |
212 | for (n = 0; n < chunk->count; n++) | |
213 | if (chunk->owners[n].owner == tree) | |
6f1b5d7a YB |
214 | return true; |
215 | return false; | |
74c3cbe3 AV |
216 | } |
217 | ||
218 | /* tagging and untagging inodes with trees */ | |
219 | ||
8f7b0ba1 AV |
220 | static struct audit_chunk *find_chunk(struct node *p) |
221 | { | |
222 | int index = p->index & ~(1U<<31); | |
223 | p -= index; | |
224 | return container_of(p, struct audit_chunk, owners[0]); | |
225 | } | |
226 | ||
227 | static void untag_chunk(struct node *p) | |
74c3cbe3 | 228 | { |
8f7b0ba1 | 229 | struct audit_chunk *chunk = find_chunk(p); |
e61ce867 | 230 | struct fsnotify_mark *entry = &chunk->mark; |
f7a998a9 | 231 | struct audit_chunk *new = NULL; |
74c3cbe3 AV |
232 | struct audit_tree *owner; |
233 | int size = chunk->count - 1; | |
234 | int i, j; | |
235 | ||
28a3a7eb | 236 | fsnotify_get_mark(entry); |
8f7b0ba1 AV |
237 | |
238 | spin_unlock(&hash_lock); | |
239 | ||
f7a998a9 AV |
240 | if (size) |
241 | new = alloc_chunk(size); | |
242 | ||
be29d20f | 243 | mutex_lock(&entry->group->mark_mutex); |
28a3a7eb | 244 | spin_lock(&entry->lock); |
6b3f05d2 JK |
245 | /* |
246 | * mark_mutex protects mark from getting detached and thus also from | |
247 | * mark->connector->inode getting NULL. | |
248 | */ | |
43471d15 | 249 | if (chunk->dead || !(entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) { |
28a3a7eb | 250 | spin_unlock(&entry->lock); |
be29d20f | 251 | mutex_unlock(&entry->group->mark_mutex); |
f7a998a9 | 252 | if (new) |
7b129323 | 253 | fsnotify_put_mark(&new->mark); |
8f7b0ba1 | 254 | goto out; |
74c3cbe3 AV |
255 | } |
256 | ||
257 | owner = p->owner; | |
258 | ||
259 | if (!size) { | |
260 | chunk->dead = 1; | |
261 | spin_lock(&hash_lock); | |
262 | list_del_init(&chunk->trees); | |
263 | if (owner->root == chunk) | |
264 | owner->root = NULL; | |
265 | list_del_init(&p->list); | |
266 | list_del_rcu(&chunk->hash); | |
267 | spin_unlock(&hash_lock); | |
28a3a7eb | 268 | spin_unlock(&entry->lock); |
be29d20f | 269 | mutex_unlock(&entry->group->mark_mutex); |
e2a29943 | 270 | fsnotify_destroy_mark(entry, audit_tree_group); |
8f7b0ba1 | 271 | goto out; |
74c3cbe3 AV |
272 | } |
273 | ||
74c3cbe3 AV |
274 | if (!new) |
275 | goto Fallback; | |
f7a998a9 | 276 | |
7b129323 | 277 | if (fsnotify_add_mark_locked(&new->mark, entry->connector->inode, |
be29d20f | 278 | NULL, 1)) { |
0fe33aae | 279 | fsnotify_put_mark(&new->mark); |
74c3cbe3 AV |
280 | goto Fallback; |
281 | } | |
282 | ||
283 | chunk->dead = 1; | |
284 | spin_lock(&hash_lock); | |
5685d81d | 285 | new->key = chunk->key; |
74c3cbe3 AV |
286 | list_replace_init(&chunk->trees, &new->trees); |
287 | if (owner->root == chunk) { | |
288 | list_del_init(&owner->same_root); | |
289 | owner->root = NULL; | |
290 | } | |
291 | ||
6f5d5114 | 292 | for (i = j = 0; j <= size; i++, j++) { |
74c3cbe3 AV |
293 | struct audit_tree *s; |
294 | if (&chunk->owners[j] == p) { | |
295 | list_del_init(&p->list); | |
296 | i--; | |
297 | continue; | |
298 | } | |
299 | s = chunk->owners[j].owner; | |
300 | new->owners[i].owner = s; | |
301 | new->owners[i].index = chunk->owners[j].index - j + i; | |
302 | if (!s) /* result of earlier fallback */ | |
303 | continue; | |
304 | get_tree(s); | |
6f5d5114 | 305 | list_replace_init(&chunk->owners[j].list, &new->owners[i].list); |
74c3cbe3 AV |
306 | } |
307 | ||
308 | list_replace_rcu(&chunk->hash, &new->hash); | |
309 | list_for_each_entry(owner, &new->trees, same_root) | |
310 | owner->root = new; | |
311 | spin_unlock(&hash_lock); | |
28a3a7eb | 312 | spin_unlock(&entry->lock); |
be29d20f | 313 | mutex_unlock(&entry->group->mark_mutex); |
e2a29943 | 314 | fsnotify_destroy_mark(entry, audit_tree_group); |
b3e8692b | 315 | fsnotify_put_mark(&new->mark); /* drop initial reference */ |
8f7b0ba1 | 316 | goto out; |
74c3cbe3 AV |
317 | |
318 | Fallback: | |
319 | // do the best we can | |
320 | spin_lock(&hash_lock); | |
321 | if (owner->root == chunk) { | |
322 | list_del_init(&owner->same_root); | |
323 | owner->root = NULL; | |
324 | } | |
325 | list_del_init(&p->list); | |
326 | p->owner = NULL; | |
327 | put_tree(owner); | |
328 | spin_unlock(&hash_lock); | |
28a3a7eb | 329 | spin_unlock(&entry->lock); |
be29d20f | 330 | mutex_unlock(&entry->group->mark_mutex); |
8f7b0ba1 | 331 | out: |
28a3a7eb | 332 | fsnotify_put_mark(entry); |
8f7b0ba1 | 333 | spin_lock(&hash_lock); |
74c3cbe3 AV |
334 | } |
335 | ||
336 | static int create_chunk(struct inode *inode, struct audit_tree *tree) | |
337 | { | |
e61ce867 | 338 | struct fsnotify_mark *entry; |
74c3cbe3 AV |
339 | struct audit_chunk *chunk = alloc_chunk(1); |
340 | if (!chunk) | |
341 | return -ENOMEM; | |
342 | ||
28a3a7eb | 343 | entry = &chunk->mark; |
7b129323 | 344 | if (fsnotify_add_mark(entry, inode, NULL, 0)) { |
0fe33aae | 345 | fsnotify_put_mark(entry); |
74c3cbe3 AV |
346 | return -ENOSPC; |
347 | } | |
348 | ||
28a3a7eb | 349 | spin_lock(&entry->lock); |
74c3cbe3 AV |
350 | spin_lock(&hash_lock); |
351 | if (tree->goner) { | |
352 | spin_unlock(&hash_lock); | |
353 | chunk->dead = 1; | |
28a3a7eb | 354 | spin_unlock(&entry->lock); |
e2a29943 | 355 | fsnotify_destroy_mark(entry, audit_tree_group); |
28a3a7eb | 356 | fsnotify_put_mark(entry); |
74c3cbe3 AV |
357 | return 0; |
358 | } | |
359 | chunk->owners[0].index = (1U << 31); | |
360 | chunk->owners[0].owner = tree; | |
361 | get_tree(tree); | |
362 | list_add(&chunk->owners[0].list, &tree->chunks); | |
363 | if (!tree->root) { | |
364 | tree->root = chunk; | |
365 | list_add(&tree->same_root, &chunk->trees); | |
366 | } | |
5685d81d | 367 | chunk->key = inode_to_key(inode); |
74c3cbe3 AV |
368 | insert_hash(chunk); |
369 | spin_unlock(&hash_lock); | |
28a3a7eb | 370 | spin_unlock(&entry->lock); |
b3e8692b | 371 | fsnotify_put_mark(entry); /* drop initial reference */ |
74c3cbe3 AV |
372 | return 0; |
373 | } | |
374 | ||
375 | /* the first tagged inode becomes root of tree */ | |
376 | static int tag_chunk(struct inode *inode, struct audit_tree *tree) | |
377 | { | |
e61ce867 | 378 | struct fsnotify_mark *old_entry, *chunk_entry; |
74c3cbe3 AV |
379 | struct audit_tree *owner; |
380 | struct audit_chunk *chunk, *old; | |
381 | struct node *p; | |
382 | int n; | |
383 | ||
b1362edf JK |
384 | old_entry = fsnotify_find_mark(&inode->i_fsnotify_marks, |
385 | audit_tree_group); | |
28a3a7eb | 386 | if (!old_entry) |
74c3cbe3 AV |
387 | return create_chunk(inode, tree); |
388 | ||
28a3a7eb | 389 | old = container_of(old_entry, struct audit_chunk, mark); |
74c3cbe3 AV |
390 | |
391 | /* are we already there? */ | |
392 | spin_lock(&hash_lock); | |
393 | for (n = 0; n < old->count; n++) { | |
394 | if (old->owners[n].owner == tree) { | |
395 | spin_unlock(&hash_lock); | |
28a3a7eb | 396 | fsnotify_put_mark(old_entry); |
74c3cbe3 AV |
397 | return 0; |
398 | } | |
399 | } | |
400 | spin_unlock(&hash_lock); | |
401 | ||
402 | chunk = alloc_chunk(old->count + 1); | |
b4c30aad | 403 | if (!chunk) { |
28a3a7eb | 404 | fsnotify_put_mark(old_entry); |
74c3cbe3 | 405 | return -ENOMEM; |
b4c30aad | 406 | } |
74c3cbe3 | 407 | |
28a3a7eb EP |
408 | chunk_entry = &chunk->mark; |
409 | ||
be29d20f | 410 | mutex_lock(&old_entry->group->mark_mutex); |
28a3a7eb | 411 | spin_lock(&old_entry->lock); |
6b3f05d2 JK |
412 | /* |
413 | * mark_mutex protects mark from getting detached and thus also from | |
414 | * mark->connector->inode getting NULL. | |
415 | */ | |
43471d15 | 416 | if (!(old_entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) { |
28a3a7eb EP |
417 | /* old_entry is being shot, lets just lie */ |
418 | spin_unlock(&old_entry->lock); | |
be29d20f | 419 | mutex_unlock(&old_entry->group->mark_mutex); |
28a3a7eb | 420 | fsnotify_put_mark(old_entry); |
7b129323 | 421 | fsnotify_put_mark(&chunk->mark); |
28a3a7eb EP |
422 | return -ENOENT; |
423 | } | |
424 | ||
7b129323 | 425 | if (fsnotify_add_mark_locked(chunk_entry, |
86ffe245 | 426 | old_entry->connector->inode, NULL, 1)) { |
28a3a7eb | 427 | spin_unlock(&old_entry->lock); |
be29d20f | 428 | mutex_unlock(&old_entry->group->mark_mutex); |
0fe33aae | 429 | fsnotify_put_mark(chunk_entry); |
28a3a7eb | 430 | fsnotify_put_mark(old_entry); |
74c3cbe3 AV |
431 | return -ENOSPC; |
432 | } | |
28a3a7eb EP |
433 | |
434 | /* even though we hold old_entry->lock, this is safe since chunk_entry->lock could NEVER have been grabbed before */ | |
435 | spin_lock(&chunk_entry->lock); | |
74c3cbe3 | 436 | spin_lock(&hash_lock); |
28a3a7eb EP |
437 | |
438 | /* we now hold old_entry->lock, chunk_entry->lock, and hash_lock */ | |
74c3cbe3 AV |
439 | if (tree->goner) { |
440 | spin_unlock(&hash_lock); | |
441 | chunk->dead = 1; | |
28a3a7eb EP |
442 | spin_unlock(&chunk_entry->lock); |
443 | spin_unlock(&old_entry->lock); | |
be29d20f | 444 | mutex_unlock(&old_entry->group->mark_mutex); |
28a3a7eb | 445 | |
e2a29943 | 446 | fsnotify_destroy_mark(chunk_entry, audit_tree_group); |
28a3a7eb EP |
447 | |
448 | fsnotify_put_mark(chunk_entry); | |
449 | fsnotify_put_mark(old_entry); | |
74c3cbe3 AV |
450 | return 0; |
451 | } | |
5685d81d | 452 | chunk->key = old->key; |
74c3cbe3 AV |
453 | list_replace_init(&old->trees, &chunk->trees); |
454 | for (n = 0, p = chunk->owners; n < old->count; n++, p++) { | |
455 | struct audit_tree *s = old->owners[n].owner; | |
456 | p->owner = s; | |
457 | p->index = old->owners[n].index; | |
458 | if (!s) /* result of fallback in untag */ | |
459 | continue; | |
460 | get_tree(s); | |
461 | list_replace_init(&old->owners[n].list, &p->list); | |
462 | } | |
463 | p->index = (chunk->count - 1) | (1U<<31); | |
464 | p->owner = tree; | |
465 | get_tree(tree); | |
466 | list_add(&p->list, &tree->chunks); | |
467 | list_replace_rcu(&old->hash, &chunk->hash); | |
468 | list_for_each_entry(owner, &chunk->trees, same_root) | |
469 | owner->root = chunk; | |
470 | old->dead = 1; | |
471 | if (!tree->root) { | |
472 | tree->root = chunk; | |
473 | list_add(&tree->same_root, &chunk->trees); | |
474 | } | |
475 | spin_unlock(&hash_lock); | |
28a3a7eb EP |
476 | spin_unlock(&chunk_entry->lock); |
477 | spin_unlock(&old_entry->lock); | |
be29d20f | 478 | mutex_unlock(&old_entry->group->mark_mutex); |
e2a29943 | 479 | fsnotify_destroy_mark(old_entry, audit_tree_group); |
b3e8692b | 480 | fsnotify_put_mark(chunk_entry); /* drop initial reference */ |
28a3a7eb | 481 | fsnotify_put_mark(old_entry); /* pair to fsnotify_find mark_entry */ |
74c3cbe3 AV |
482 | return 0; |
483 | } | |
484 | ||
2991dd2b | 485 | static void audit_tree_log_remove_rule(struct audit_krule *rule) |
0644ec0c KC |
486 | { |
487 | struct audit_buffer *ab; | |
488 | ||
489 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); | |
490 | if (unlikely(!ab)) | |
491 | return; | |
c1e8f06d | 492 | audit_log_format(ab, "op=remove_rule"); |
0644ec0c KC |
493 | audit_log_format(ab, " dir="); |
494 | audit_log_untrustedstring(ab, rule->tree->pathname); | |
495 | audit_log_key(ab, rule->filterkey); | |
496 | audit_log_format(ab, " list=%d res=1", rule->listnr); | |
497 | audit_log_end(ab); | |
498 | } | |
499 | ||
74c3cbe3 AV |
500 | static void kill_rules(struct audit_tree *tree) |
501 | { | |
502 | struct audit_krule *rule, *next; | |
503 | struct audit_entry *entry; | |
74c3cbe3 AV |
504 | |
505 | list_for_each_entry_safe(rule, next, &tree->rules, rlist) { | |
506 | entry = container_of(rule, struct audit_entry, rule); | |
507 | ||
508 | list_del_init(&rule->rlist); | |
509 | if (rule->tree) { | |
510 | /* not a half-baked one */ | |
2991dd2b | 511 | audit_tree_log_remove_rule(rule); |
34d99af5 RGB |
512 | if (entry->rule.exe) |
513 | audit_remove_mark(entry->rule.exe); | |
74c3cbe3 AV |
514 | rule->tree = NULL; |
515 | list_del_rcu(&entry->list); | |
e45aa212 | 516 | list_del(&entry->rule.list); |
74c3cbe3 AV |
517 | call_rcu(&entry->rcu, audit_free_rule_rcu); |
518 | } | |
519 | } | |
520 | } | |
521 | ||
522 | /* | |
523 | * finish killing struct audit_tree | |
524 | */ | |
525 | static void prune_one(struct audit_tree *victim) | |
526 | { | |
527 | spin_lock(&hash_lock); | |
528 | while (!list_empty(&victim->chunks)) { | |
529 | struct node *p; | |
74c3cbe3 AV |
530 | |
531 | p = list_entry(victim->chunks.next, struct node, list); | |
74c3cbe3 | 532 | |
8f7b0ba1 | 533 | untag_chunk(p); |
74c3cbe3 AV |
534 | } |
535 | spin_unlock(&hash_lock); | |
536 | put_tree(victim); | |
537 | } | |
538 | ||
539 | /* trim the uncommitted chunks from tree */ | |
540 | ||
541 | static void trim_marked(struct audit_tree *tree) | |
542 | { | |
543 | struct list_head *p, *q; | |
544 | spin_lock(&hash_lock); | |
545 | if (tree->goner) { | |
546 | spin_unlock(&hash_lock); | |
547 | return; | |
548 | } | |
549 | /* reorder */ | |
550 | for (p = tree->chunks.next; p != &tree->chunks; p = q) { | |
551 | struct node *node = list_entry(p, struct node, list); | |
552 | q = p->next; | |
553 | if (node->index & (1U<<31)) { | |
554 | list_del_init(p); | |
555 | list_add(p, &tree->chunks); | |
556 | } | |
557 | } | |
558 | ||
559 | while (!list_empty(&tree->chunks)) { | |
560 | struct node *node; | |
74c3cbe3 AV |
561 | |
562 | node = list_entry(tree->chunks.next, struct node, list); | |
563 | ||
564 | /* have we run out of marked? */ | |
565 | if (!(node->index & (1U<<31))) | |
566 | break; | |
567 | ||
8f7b0ba1 | 568 | untag_chunk(node); |
74c3cbe3 AV |
569 | } |
570 | if (!tree->root && !tree->goner) { | |
571 | tree->goner = 1; | |
572 | spin_unlock(&hash_lock); | |
573 | mutex_lock(&audit_filter_mutex); | |
574 | kill_rules(tree); | |
575 | list_del_init(&tree->list); | |
576 | mutex_unlock(&audit_filter_mutex); | |
577 | prune_one(tree); | |
578 | } else { | |
579 | spin_unlock(&hash_lock); | |
580 | } | |
581 | } | |
582 | ||
916d7576 AV |
583 | static void audit_schedule_prune(void); |
584 | ||
74c3cbe3 AV |
585 | /* called with audit_filter_mutex */ |
586 | int audit_remove_tree_rule(struct audit_krule *rule) | |
587 | { | |
588 | struct audit_tree *tree; | |
589 | tree = rule->tree; | |
590 | if (tree) { | |
591 | spin_lock(&hash_lock); | |
592 | list_del_init(&rule->rlist); | |
593 | if (list_empty(&tree->rules) && !tree->goner) { | |
594 | tree->root = NULL; | |
595 | list_del_init(&tree->same_root); | |
596 | tree->goner = 1; | |
597 | list_move(&tree->list, &prune_list); | |
598 | rule->tree = NULL; | |
599 | spin_unlock(&hash_lock); | |
600 | audit_schedule_prune(); | |
601 | return 1; | |
602 | } | |
603 | rule->tree = NULL; | |
604 | spin_unlock(&hash_lock); | |
605 | return 1; | |
606 | } | |
607 | return 0; | |
608 | } | |
609 | ||
1f707137 AV |
610 | static int compare_root(struct vfsmount *mnt, void *arg) |
611 | { | |
f410ff65 JK |
612 | return inode_to_key(d_backing_inode(mnt->mnt_root)) == |
613 | (unsigned long)arg; | |
1f707137 AV |
614 | } |
615 | ||
74c3cbe3 AV |
616 | void audit_trim_trees(void) |
617 | { | |
618 | struct list_head cursor; | |
619 | ||
620 | mutex_lock(&audit_filter_mutex); | |
621 | list_add(&cursor, &tree_list); | |
622 | while (cursor.next != &tree_list) { | |
623 | struct audit_tree *tree; | |
98bc993f | 624 | struct path path; |
74c3cbe3 AV |
625 | struct vfsmount *root_mnt; |
626 | struct node *node; | |
74c3cbe3 AV |
627 | int err; |
628 | ||
629 | tree = container_of(cursor.next, struct audit_tree, list); | |
630 | get_tree(tree); | |
631 | list_del(&cursor); | |
632 | list_add(&cursor, &tree->list); | |
633 | mutex_unlock(&audit_filter_mutex); | |
634 | ||
98bc993f | 635 | err = kern_path(tree->pathname, 0, &path); |
74c3cbe3 AV |
636 | if (err) |
637 | goto skip_it; | |
638 | ||
589ff870 | 639 | root_mnt = collect_mounts(&path); |
98bc993f | 640 | path_put(&path); |
be34d1a3 | 641 | if (IS_ERR(root_mnt)) |
74c3cbe3 AV |
642 | goto skip_it; |
643 | ||
74c3cbe3 AV |
644 | spin_lock(&hash_lock); |
645 | list_for_each_entry(node, &tree->chunks, list) { | |
28a3a7eb | 646 | struct audit_chunk *chunk = find_chunk(node); |
25985edc | 647 | /* this could be NULL if the watch is dying else where... */ |
74c3cbe3 | 648 | node->index |= 1U<<31; |
f410ff65 | 649 | if (iterate_mounts(compare_root, |
5685d81d | 650 | (void *)(chunk->key), |
f410ff65 | 651 | root_mnt)) |
1f707137 | 652 | node->index &= ~(1U<<31); |
74c3cbe3 AV |
653 | } |
654 | spin_unlock(&hash_lock); | |
655 | trim_marked(tree); | |
74c3cbe3 AV |
656 | drop_collected_mounts(root_mnt); |
657 | skip_it: | |
12b2f117 | 658 | put_tree(tree); |
74c3cbe3 AV |
659 | mutex_lock(&audit_filter_mutex); |
660 | } | |
661 | list_del(&cursor); | |
662 | mutex_unlock(&audit_filter_mutex); | |
663 | } | |
664 | ||
74c3cbe3 AV |
665 | int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op) |
666 | { | |
667 | ||
668 | if (pathname[0] != '/' || | |
669 | rule->listnr != AUDIT_FILTER_EXIT || | |
5af75d8d | 670 | op != Audit_equal || |
74c3cbe3 AV |
671 | rule->inode_f || rule->watch || rule->tree) |
672 | return -EINVAL; | |
673 | rule->tree = alloc_tree(pathname); | |
674 | if (!rule->tree) | |
675 | return -ENOMEM; | |
676 | return 0; | |
677 | } | |
678 | ||
679 | void audit_put_tree(struct audit_tree *tree) | |
680 | { | |
681 | put_tree(tree); | |
682 | } | |
683 | ||
1f707137 AV |
684 | static int tag_mount(struct vfsmount *mnt, void *arg) |
685 | { | |
3b362157 | 686 | return tag_chunk(d_backing_inode(mnt->mnt_root), arg); |
1f707137 AV |
687 | } |
688 | ||
f1aaf262 IP |
689 | /* |
690 | * That gets run when evict_chunk() ends up needing to kill audit_tree. | |
691 | * Runs from a separate thread. | |
692 | */ | |
693 | static int prune_tree_thread(void *unused) | |
694 | { | |
695 | for (;;) { | |
0bf676d1 JS |
696 | if (list_empty(&prune_list)) { |
697 | set_current_state(TASK_INTERRUPTIBLE); | |
f1aaf262 | 698 | schedule(); |
0bf676d1 | 699 | } |
f1aaf262 IP |
700 | |
701 | mutex_lock(&audit_cmd_mutex); | |
702 | mutex_lock(&audit_filter_mutex); | |
703 | ||
704 | while (!list_empty(&prune_list)) { | |
705 | struct audit_tree *victim; | |
706 | ||
707 | victim = list_entry(prune_list.next, | |
708 | struct audit_tree, list); | |
709 | list_del_init(&victim->list); | |
710 | ||
711 | mutex_unlock(&audit_filter_mutex); | |
712 | ||
713 | prune_one(victim); | |
714 | ||
715 | mutex_lock(&audit_filter_mutex); | |
716 | } | |
717 | ||
718 | mutex_unlock(&audit_filter_mutex); | |
719 | mutex_unlock(&audit_cmd_mutex); | |
720 | } | |
721 | return 0; | |
722 | } | |
723 | ||
724 | static int audit_launch_prune(void) | |
725 | { | |
726 | if (prune_thread) | |
727 | return 0; | |
0bf676d1 | 728 | prune_thread = kthread_run(prune_tree_thread, NULL, |
f1aaf262 IP |
729 | "audit_prune_tree"); |
730 | if (IS_ERR(prune_thread)) { | |
731 | pr_err("cannot start thread audit_prune_tree"); | |
732 | prune_thread = NULL; | |
733 | return -ENOMEM; | |
f1aaf262 | 734 | } |
0bf676d1 | 735 | return 0; |
f1aaf262 IP |
736 | } |
737 | ||
74c3cbe3 AV |
738 | /* called with audit_filter_mutex */ |
739 | int audit_add_tree_rule(struct audit_krule *rule) | |
740 | { | |
741 | struct audit_tree *seed = rule->tree, *tree; | |
98bc993f | 742 | struct path path; |
1f707137 | 743 | struct vfsmount *mnt; |
74c3cbe3 AV |
744 | int err; |
745 | ||
736f3203 | 746 | rule->tree = NULL; |
74c3cbe3 AV |
747 | list_for_each_entry(tree, &tree_list, list) { |
748 | if (!strcmp(seed->pathname, tree->pathname)) { | |
749 | put_tree(seed); | |
750 | rule->tree = tree; | |
751 | list_add(&rule->rlist, &tree->rules); | |
752 | return 0; | |
753 | } | |
754 | } | |
755 | tree = seed; | |
756 | list_add(&tree->list, &tree_list); | |
757 | list_add(&rule->rlist, &tree->rules); | |
758 | /* do not set rule->tree yet */ | |
759 | mutex_unlock(&audit_filter_mutex); | |
760 | ||
f1aaf262 IP |
761 | if (unlikely(!prune_thread)) { |
762 | err = audit_launch_prune(); | |
763 | if (err) | |
764 | goto Err; | |
765 | } | |
766 | ||
98bc993f | 767 | err = kern_path(tree->pathname, 0, &path); |
74c3cbe3 AV |
768 | if (err) |
769 | goto Err; | |
589ff870 | 770 | mnt = collect_mounts(&path); |
98bc993f | 771 | path_put(&path); |
be34d1a3 DH |
772 | if (IS_ERR(mnt)) { |
773 | err = PTR_ERR(mnt); | |
74c3cbe3 AV |
774 | goto Err; |
775 | } | |
74c3cbe3 AV |
776 | |
777 | get_tree(tree); | |
1f707137 | 778 | err = iterate_mounts(tag_mount, tree, mnt); |
74c3cbe3 AV |
779 | drop_collected_mounts(mnt); |
780 | ||
781 | if (!err) { | |
782 | struct node *node; | |
783 | spin_lock(&hash_lock); | |
784 | list_for_each_entry(node, &tree->chunks, list) | |
785 | node->index &= ~(1U<<31); | |
786 | spin_unlock(&hash_lock); | |
787 | } else { | |
788 | trim_marked(tree); | |
789 | goto Err; | |
790 | } | |
791 | ||
792 | mutex_lock(&audit_filter_mutex); | |
793 | if (list_empty(&rule->rlist)) { | |
794 | put_tree(tree); | |
795 | return -ENOENT; | |
796 | } | |
797 | rule->tree = tree; | |
798 | put_tree(tree); | |
799 | ||
800 | return 0; | |
801 | Err: | |
802 | mutex_lock(&audit_filter_mutex); | |
803 | list_del_init(&tree->list); | |
804 | list_del_init(&tree->rules); | |
805 | put_tree(tree); | |
806 | return err; | |
807 | } | |
808 | ||
809 | int audit_tag_tree(char *old, char *new) | |
810 | { | |
811 | struct list_head cursor, barrier; | |
812 | int failed = 0; | |
2096f759 | 813 | struct path path1, path2; |
74c3cbe3 | 814 | struct vfsmount *tagged; |
74c3cbe3 AV |
815 | int err; |
816 | ||
2096f759 | 817 | err = kern_path(new, 0, &path2); |
74c3cbe3 AV |
818 | if (err) |
819 | return err; | |
2096f759 AV |
820 | tagged = collect_mounts(&path2); |
821 | path_put(&path2); | |
be34d1a3 DH |
822 | if (IS_ERR(tagged)) |
823 | return PTR_ERR(tagged); | |
74c3cbe3 | 824 | |
2096f759 | 825 | err = kern_path(old, 0, &path1); |
74c3cbe3 AV |
826 | if (err) { |
827 | drop_collected_mounts(tagged); | |
828 | return err; | |
829 | } | |
74c3cbe3 | 830 | |
74c3cbe3 AV |
831 | mutex_lock(&audit_filter_mutex); |
832 | list_add(&barrier, &tree_list); | |
833 | list_add(&cursor, &barrier); | |
834 | ||
835 | while (cursor.next != &tree_list) { | |
836 | struct audit_tree *tree; | |
2096f759 | 837 | int good_one = 0; |
74c3cbe3 AV |
838 | |
839 | tree = container_of(cursor.next, struct audit_tree, list); | |
840 | get_tree(tree); | |
841 | list_del(&cursor); | |
842 | list_add(&cursor, &tree->list); | |
843 | mutex_unlock(&audit_filter_mutex); | |
844 | ||
2096f759 AV |
845 | err = kern_path(tree->pathname, 0, &path2); |
846 | if (!err) { | |
847 | good_one = path_is_under(&path1, &path2); | |
848 | path_put(&path2); | |
74c3cbe3 AV |
849 | } |
850 | ||
2096f759 | 851 | if (!good_one) { |
74c3cbe3 AV |
852 | put_tree(tree); |
853 | mutex_lock(&audit_filter_mutex); | |
854 | continue; | |
855 | } | |
74c3cbe3 | 856 | |
1f707137 | 857 | failed = iterate_mounts(tag_mount, tree, tagged); |
74c3cbe3 AV |
858 | if (failed) { |
859 | put_tree(tree); | |
860 | mutex_lock(&audit_filter_mutex); | |
861 | break; | |
862 | } | |
863 | ||
864 | mutex_lock(&audit_filter_mutex); | |
865 | spin_lock(&hash_lock); | |
866 | if (!tree->goner) { | |
867 | list_del(&tree->list); | |
868 | list_add(&tree->list, &tree_list); | |
869 | } | |
870 | spin_unlock(&hash_lock); | |
871 | put_tree(tree); | |
872 | } | |
873 | ||
874 | while (barrier.prev != &tree_list) { | |
875 | struct audit_tree *tree; | |
876 | ||
877 | tree = container_of(barrier.prev, struct audit_tree, list); | |
878 | get_tree(tree); | |
879 | list_del(&tree->list); | |
880 | list_add(&tree->list, &barrier); | |
881 | mutex_unlock(&audit_filter_mutex); | |
882 | ||
883 | if (!failed) { | |
884 | struct node *node; | |
885 | spin_lock(&hash_lock); | |
886 | list_for_each_entry(node, &tree->chunks, list) | |
887 | node->index &= ~(1U<<31); | |
888 | spin_unlock(&hash_lock); | |
889 | } else { | |
890 | trim_marked(tree); | |
891 | } | |
892 | ||
893 | put_tree(tree); | |
894 | mutex_lock(&audit_filter_mutex); | |
895 | } | |
896 | list_del(&barrier); | |
897 | list_del(&cursor); | |
74c3cbe3 | 898 | mutex_unlock(&audit_filter_mutex); |
2096f759 | 899 | path_put(&path1); |
74c3cbe3 AV |
900 | drop_collected_mounts(tagged); |
901 | return failed; | |
902 | } | |
903 | ||
916d7576 AV |
904 | |
905 | static void audit_schedule_prune(void) | |
906 | { | |
f1aaf262 | 907 | wake_up_process(prune_thread); |
916d7576 AV |
908 | } |
909 | ||
910 | /* | |
911 | * ... and that one is done if evict_chunk() decides to delay until the end | |
912 | * of syscall. Runs synchronously. | |
913 | */ | |
914 | void audit_kill_trees(struct list_head *list) | |
915 | { | |
916 | mutex_lock(&audit_cmd_mutex); | |
917 | mutex_lock(&audit_filter_mutex); | |
918 | ||
919 | while (!list_empty(list)) { | |
920 | struct audit_tree *victim; | |
921 | ||
922 | victim = list_entry(list->next, struct audit_tree, list); | |
923 | kill_rules(victim); | |
924 | list_del_init(&victim->list); | |
925 | ||
926 | mutex_unlock(&audit_filter_mutex); | |
927 | ||
928 | prune_one(victim); | |
929 | ||
930 | mutex_lock(&audit_filter_mutex); | |
931 | } | |
932 | ||
933 | mutex_unlock(&audit_filter_mutex); | |
934 | mutex_unlock(&audit_cmd_mutex); | |
74c3cbe3 AV |
935 | } |
936 | ||
937 | /* | |
938 | * Here comes the stuff asynchronous to auditctl operations | |
939 | */ | |
940 | ||
74c3cbe3 AV |
941 | static void evict_chunk(struct audit_chunk *chunk) |
942 | { | |
943 | struct audit_tree *owner; | |
916d7576 AV |
944 | struct list_head *postponed = audit_killed_trees(); |
945 | int need_prune = 0; | |
74c3cbe3 AV |
946 | int n; |
947 | ||
948 | if (chunk->dead) | |
949 | return; | |
950 | ||
951 | chunk->dead = 1; | |
952 | mutex_lock(&audit_filter_mutex); | |
953 | spin_lock(&hash_lock); | |
954 | while (!list_empty(&chunk->trees)) { | |
955 | owner = list_entry(chunk->trees.next, | |
956 | struct audit_tree, same_root); | |
957 | owner->goner = 1; | |
958 | owner->root = NULL; | |
959 | list_del_init(&owner->same_root); | |
960 | spin_unlock(&hash_lock); | |
916d7576 AV |
961 | if (!postponed) { |
962 | kill_rules(owner); | |
963 | list_move(&owner->list, &prune_list); | |
964 | need_prune = 1; | |
965 | } else { | |
966 | list_move(&owner->list, postponed); | |
967 | } | |
74c3cbe3 AV |
968 | spin_lock(&hash_lock); |
969 | } | |
970 | list_del_rcu(&chunk->hash); | |
971 | for (n = 0; n < chunk->count; n++) | |
972 | list_del_init(&chunk->owners[n].list); | |
973 | spin_unlock(&hash_lock); | |
f1aaf262 | 974 | mutex_unlock(&audit_filter_mutex); |
916d7576 AV |
975 | if (need_prune) |
976 | audit_schedule_prune(); | |
74c3cbe3 AV |
977 | } |
978 | ||
3a9b16b4 | 979 | static int audit_tree_handle_event(struct fsnotify_group *group, |
7053aee2 | 980 | struct inode *to_tell, |
ce8f76fb | 981 | struct fsnotify_mark *inode_mark, |
7053aee2 | 982 | struct fsnotify_mark *vfsmount_mark, |
3cd5eca8 | 983 | u32 mask, const void *data, int data_type, |
9385a84d JK |
984 | const unsigned char *file_name, u32 cookie, |
985 | struct fsnotify_iter_info *iter_info) | |
74c3cbe3 | 986 | { |
83c4c4b0 | 987 | return 0; |
28a3a7eb | 988 | } |
74c3cbe3 | 989 | |
e61ce867 | 990 | static void audit_tree_freeing_mark(struct fsnotify_mark *entry, struct fsnotify_group *group) |
28a3a7eb EP |
991 | { |
992 | struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark); | |
993 | ||
994 | evict_chunk(chunk); | |
b3e8692b MS |
995 | |
996 | /* | |
997 | * We are guaranteed to have at least one reference to the mark from | |
998 | * either the inode or the caller of fsnotify_destroy_mark(). | |
999 | */ | |
ab97f873 | 1000 | BUG_ON(refcount_read(&entry->refcnt) < 1); |
74c3cbe3 AV |
1001 | } |
1002 | ||
28a3a7eb EP |
1003 | static const struct fsnotify_ops audit_tree_ops = { |
1004 | .handle_event = audit_tree_handle_event, | |
28a3a7eb | 1005 | .freeing_mark = audit_tree_freeing_mark, |
054c636e | 1006 | .free_mark = audit_tree_destroy_watch, |
74c3cbe3 AV |
1007 | }; |
1008 | ||
1009 | static int __init audit_tree_init(void) | |
1010 | { | |
1011 | int i; | |
1012 | ||
0d2e2a1d | 1013 | audit_tree_group = fsnotify_alloc_group(&audit_tree_ops); |
28a3a7eb EP |
1014 | if (IS_ERR(audit_tree_group)) |
1015 | audit_panic("cannot initialize fsnotify group for rectree watches"); | |
74c3cbe3 AV |
1016 | |
1017 | for (i = 0; i < HASH_SIZE; i++) | |
1018 | INIT_LIST_HEAD(&chunk_hash_heads[i]); | |
1019 | ||
1020 | return 0; | |
1021 | } | |
1022 | __initcall(audit_tree_init); |