Blame view
kernel/audit_tree.c
23.9 KB
b24413180
|
1 |
// SPDX-License-Identifier: GPL-2.0 |
74c3cbe33
|
2 |
#include "audit.h" |
28a3a7eb3
|
3 |
#include <linux/fsnotify_backend.h> |
74c3cbe33
|
4 5 |
#include <linux/namei.h> #include <linux/mount.h> |
916d75761
|
6 |
#include <linux/kthread.h> |
9d2378f8c
|
7 |
#include <linux/refcount.h> |
5a0e3ad6a
|
8 |
#include <linux/slab.h> |
74c3cbe33
|
9 10 11 12 13 |
struct audit_tree; struct audit_chunk; struct audit_tree { |
9d2378f8c
|
14 |
refcount_t count; |
74c3cbe33
|
15 16 17 18 19 20 21 22 23 24 25 26 |
int goner; struct audit_chunk *root; struct list_head chunks; struct list_head rules; struct list_head list; struct list_head same_root; struct rcu_head head; char pathname[]; }; struct audit_chunk { struct list_head hash; |
e61ce8673
|
27 |
struct fsnotify_mark mark; |
74c3cbe33
|
28 29 30 |
struct list_head trees; /* with root here */ int dead; int count; |
8f7b0ba1c
|
31 |
atomic_long_t refs; |
74c3cbe33
|
32 33 34 35 36 37 38 39 40 41 |
struct rcu_head head; struct node { struct list_head list; struct audit_tree *owner; unsigned index; /* index; upper bit indicates 'will prune' */ } owners[]; }; static LIST_HEAD(tree_list); static LIST_HEAD(prune_list); |
f1aaf2622
|
42 |
static struct task_struct *prune_thread; |
74c3cbe33
|
43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 |
/* * One struct chunk is attached to each inode of interest. * We replace struct chunk on tagging/untagging. * Rules have pointer to struct audit_tree. * Rules have struct list_head rlist forming a list of rules over * the same tree. * References to struct chunk are collected at audit_inode{,_child}() * time and used in AUDIT_TREE rule matching. * These references are dropped at the same time we are calling * audit_free_names(), etc. * * Cyclic lists galore: * tree.chunks anchors chunk.owners[].list hash_lock * tree.rules anchors rule.rlist audit_filter_mutex * chunk.trees anchors tree.same_root hash_lock * chunk.hash is a hash with middle bits of watch.inode as * a hash function. RCU, hash_lock * * tree is refcounted; one reference for "some rules on rules_list refer to * it", one for each chunk with pointer to it. * |
28a3a7eb3
|
65 |
* chunk is refcounted by embedded fsnotify_mark + .refs (non-zero refcount |
8f7b0ba1c
|
66 |
* of watch contributes 1 to .refs). |
74c3cbe33
|
67 68 69 70 71 72 |
* * node.index allows to get from node.list to containing chunk. * MSB of that sucker is stolen to mark taggings that we might have to * revert - several operations have very unpleasant cleanup logics and * that makes a difference. Some. */ |
28a3a7eb3
|
73 |
static struct fsnotify_group *audit_tree_group; |
74c3cbe33
|
74 75 76 77 78 79 80 |
static struct audit_tree *alloc_tree(const char *s) { struct audit_tree *tree; tree = kmalloc(sizeof(struct audit_tree) + strlen(s) + 1, GFP_KERNEL); if (tree) { |
9d2378f8c
|
81 |
refcount_set(&tree->count, 1); |
74c3cbe33
|
82 83 84 85 86 87 88 89 90 91 92 93 94 |
tree->goner = 0; INIT_LIST_HEAD(&tree->chunks); INIT_LIST_HEAD(&tree->rules); INIT_LIST_HEAD(&tree->list); INIT_LIST_HEAD(&tree->same_root); tree->root = NULL; strcpy(tree->pathname, s); } return tree; } static inline void get_tree(struct audit_tree *tree) { |
9d2378f8c
|
95 |
refcount_inc(&tree->count); |
74c3cbe33
|
96 |
} |
74c3cbe33
|
97 98 |
static inline void put_tree(struct audit_tree *tree) { |
9d2378f8c
|
99 |
if (refcount_dec_and_test(&tree->count)) |
3b097c469
|
100 |
kfree_rcu(tree, head); |
74c3cbe33
|
101 102 103 104 105 106 107 |
} /* to avoid bringing the entire thing in audit.h */ const char *audit_tree_path(struct audit_tree *tree) { return tree->pathname; } |
8f7b0ba1c
|
108 |
static void free_chunk(struct audit_chunk *chunk) |
74c3cbe33
|
109 |
{ |
74c3cbe33
|
110 111 112 113 114 115 116 117 |
int i; for (i = 0; i < chunk->count; i++) { if (chunk->owners[i].owner) put_tree(chunk->owners[i].owner); } kfree(chunk); } |
8f7b0ba1c
|
118 |
void audit_put_chunk(struct audit_chunk *chunk) |
74c3cbe33
|
119 |
{ |
8f7b0ba1c
|
120 121 |
if (atomic_long_dec_and_test(&chunk->refs)) free_chunk(chunk); |
74c3cbe33
|
122 |
} |
8f7b0ba1c
|
123 |
static void __put_chunk(struct rcu_head *rcu) |
74c3cbe33
|
124 |
{ |
8f7b0ba1c
|
125 126 |
struct audit_chunk *chunk = container_of(rcu, struct audit_chunk, head); audit_put_chunk(chunk); |
74c3cbe33
|
127 |
} |
e61ce8673
|
128 |
static void audit_tree_destroy_watch(struct fsnotify_mark *entry) |
28a3a7eb3
|
129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 |
{ struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark); call_rcu(&chunk->head, __put_chunk); } static struct audit_chunk *alloc_chunk(int count) { struct audit_chunk *chunk; size_t size; int i; size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node); chunk = kzalloc(size, GFP_KERNEL); if (!chunk) return NULL; INIT_LIST_HEAD(&chunk->hash); INIT_LIST_HEAD(&chunk->trees); chunk->count = count; atomic_long_set(&chunk->refs, 1); for (i = 0; i < count; i++) { INIT_LIST_HEAD(&chunk->owners[i].list); chunk->owners[i].index = i; } |
054c636e5
|
153 |
fsnotify_init_mark(&chunk->mark, audit_tree_group); |
799b60145
|
154 |
chunk->mark.mask = FS_IN_IGNORED; |
28a3a7eb3
|
155 156 |
return chunk; } |
74c3cbe33
|
157 158 159 |
enum {HASH_SIZE = 128}; static struct list_head chunk_hash_heads[HASH_SIZE]; static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock); |
f410ff655
|
160 161 |
/* Function to return search key in our hash from inode. */ static unsigned long inode_to_key(const struct inode *inode) |
74c3cbe33
|
162 |
{ |
f410ff655
|
163 164 165 166 167 168 169 |
return (unsigned long)inode; } /* * Function to return search key in our hash from chunk. Key 0 is special and * should never be present in the hash. */ |
6b3f05d24
|
170 |
static unsigned long chunk_to_key(struct audit_chunk *chunk) |
86ffe245c
|
171 |
{ |
6b3f05d24
|
172 173 174 175 176 |
/* * We have a reference to the mark so it should be attached to a * connector. */ if (WARN_ON_ONCE(!chunk->mark.connector)) |
86ffe245c
|
177 178 179 |
return 0; return (unsigned long)chunk->mark.connector->inode; } |
f410ff655
|
180 181 182 |
static inline struct list_head *chunk_hash(unsigned long key) { unsigned long n = key / L1_CACHE_BYTES; |
74c3cbe33
|
183 184 |
return chunk_hash_heads + n % HASH_SIZE; } |
28a3a7eb3
|
185 |
/* hash_lock & entry->lock is held by caller */ |
74c3cbe33
|
186 187 |
static void insert_hash(struct audit_chunk *chunk) { |
6b3f05d24
|
188 |
unsigned long key = chunk_to_key(chunk); |
28a3a7eb3
|
189 |
struct list_head *list; |
43471d15d
|
190 |
if (!(chunk->mark.flags & FSNOTIFY_MARK_FLAG_ATTACHED)) |
28a3a7eb3
|
191 |
return; |
f410ff655
|
192 |
list = chunk_hash(key); |
74c3cbe33
|
193 194 195 196 197 198 |
list_add_rcu(&chunk->hash, list); } /* called under rcu_read_lock */ struct audit_chunk *audit_tree_lookup(const struct inode *inode) { |
f410ff655
|
199 200 |
unsigned long key = inode_to_key(inode); struct list_head *list = chunk_hash(key); |
6793a051f
|
201 |
struct audit_chunk *p; |
74c3cbe33
|
202 |
|
6793a051f
|
203 |
list_for_each_entry_rcu(p, list, hash) { |
f410ff655
|
204 |
if (chunk_to_key(p) == key) { |
8f7b0ba1c
|
205 |
atomic_long_inc(&p->refs); |
74c3cbe33
|
206 207 208 209 210 |
return p; } } return NULL; } |
6f1b5d7af
|
211 |
bool audit_tree_match(struct audit_chunk *chunk, struct audit_tree *tree) |
74c3cbe33
|
212 213 214 215 |
{ int n; for (n = 0; n < chunk->count; n++) if (chunk->owners[n].owner == tree) |
6f1b5d7af
|
216 217 |
return true; return false; |
74c3cbe33
|
218 219 220 |
} /* tagging and untagging inodes with trees */ |
8f7b0ba1c
|
221 222 223 224 225 226 227 228 |
static struct audit_chunk *find_chunk(struct node *p) { int index = p->index & ~(1U<<31); p -= index; return container_of(p, struct audit_chunk, owners[0]); } static void untag_chunk(struct node *p) |
74c3cbe33
|
229 |
{ |
8f7b0ba1c
|
230 |
struct audit_chunk *chunk = find_chunk(p); |
e61ce8673
|
231 |
struct fsnotify_mark *entry = &chunk->mark; |
f7a998a94
|
232 |
struct audit_chunk *new = NULL; |
74c3cbe33
|
233 234 235 |
struct audit_tree *owner; int size = chunk->count - 1; int i, j; |
28a3a7eb3
|
236 |
fsnotify_get_mark(entry); |
8f7b0ba1c
|
237 238 |
spin_unlock(&hash_lock); |
f7a998a94
|
239 240 |
if (size) new = alloc_chunk(size); |
be29d20f3
|
241 |
mutex_lock(&entry->group->mark_mutex); |
28a3a7eb3
|
242 |
spin_lock(&entry->lock); |
6b3f05d24
|
243 244 245 246 |
/* * mark_mutex protects mark from getting detached and thus also from * mark->connector->inode getting NULL. */ |
43471d15d
|
247 |
if (chunk->dead || !(entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) { |
28a3a7eb3
|
248 |
spin_unlock(&entry->lock); |
be29d20f3
|
249 |
mutex_unlock(&entry->group->mark_mutex); |
f7a998a94
|
250 |
if (new) |
7b1293234
|
251 |
fsnotify_put_mark(&new->mark); |
8f7b0ba1c
|
252 |
goto out; |
74c3cbe33
|
253 254 255 256 257 258 259 260 261 262 263 264 265 |
} owner = p->owner; if (!size) { chunk->dead = 1; spin_lock(&hash_lock); list_del_init(&chunk->trees); if (owner->root == chunk) owner->root = NULL; list_del_init(&p->list); list_del_rcu(&chunk->hash); spin_unlock(&hash_lock); |
28a3a7eb3
|
266 |
spin_unlock(&entry->lock); |
be29d20f3
|
267 |
mutex_unlock(&entry->group->mark_mutex); |
e2a29943e
|
268 |
fsnotify_destroy_mark(entry, audit_tree_group); |
8f7b0ba1c
|
269 |
goto out; |
74c3cbe33
|
270 |
} |
74c3cbe33
|
271 272 |
if (!new) goto Fallback; |
f7a998a94
|
273 |
|
7b1293234
|
274 |
if (fsnotify_add_mark_locked(&new->mark, entry->connector->inode, |
be29d20f3
|
275 |
NULL, 1)) { |
0fe33aae0
|
276 |
fsnotify_put_mark(&new->mark); |
74c3cbe33
|
277 278 279 280 281 282 283 284 285 286 |
goto Fallback; } chunk->dead = 1; spin_lock(&hash_lock); list_replace_init(&chunk->trees, &new->trees); if (owner->root == chunk) { list_del_init(&owner->same_root); owner->root = NULL; } |
6f5d51148
|
287 |
for (i = j = 0; j <= size; i++, j++) { |
74c3cbe33
|
288 289 290 291 292 293 294 295 296 297 298 299 |
struct audit_tree *s; if (&chunk->owners[j] == p) { list_del_init(&p->list); i--; continue; } s = chunk->owners[j].owner; new->owners[i].owner = s; new->owners[i].index = chunk->owners[j].index - j + i; if (!s) /* result of earlier fallback */ continue; get_tree(s); |
6f5d51148
|
300 |
list_replace_init(&chunk->owners[j].list, &new->owners[i].list); |
74c3cbe33
|
301 302 303 304 305 306 |
} list_replace_rcu(&chunk->hash, &new->hash); list_for_each_entry(owner, &new->trees, same_root) owner->root = new; spin_unlock(&hash_lock); |
28a3a7eb3
|
307 |
spin_unlock(&entry->lock); |
be29d20f3
|
308 |
mutex_unlock(&entry->group->mark_mutex); |
e2a29943e
|
309 |
fsnotify_destroy_mark(entry, audit_tree_group); |
b3e8692b4
|
310 |
fsnotify_put_mark(&new->mark); /* drop initial reference */ |
8f7b0ba1c
|
311 |
goto out; |
74c3cbe33
|
312 313 314 315 316 317 318 319 320 321 322 323 |
Fallback: // do the best we can spin_lock(&hash_lock); if (owner->root == chunk) { list_del_init(&owner->same_root); owner->root = NULL; } list_del_init(&p->list); p->owner = NULL; put_tree(owner); spin_unlock(&hash_lock); |
28a3a7eb3
|
324 |
spin_unlock(&entry->lock); |
be29d20f3
|
325 |
mutex_unlock(&entry->group->mark_mutex); |
8f7b0ba1c
|
326 |
out: |
28a3a7eb3
|
327 |
fsnotify_put_mark(entry); |
8f7b0ba1c
|
328 |
spin_lock(&hash_lock); |
74c3cbe33
|
329 330 331 332 |
} static int create_chunk(struct inode *inode, struct audit_tree *tree) { |
e61ce8673
|
333 |
struct fsnotify_mark *entry; |
74c3cbe33
|
334 335 336 |
struct audit_chunk *chunk = alloc_chunk(1); if (!chunk) return -ENOMEM; |
28a3a7eb3
|
337 |
entry = &chunk->mark; |
7b1293234
|
338 |
if (fsnotify_add_mark(entry, inode, NULL, 0)) { |
0fe33aae0
|
339 |
fsnotify_put_mark(entry); |
74c3cbe33
|
340 341 |
return -ENOSPC; } |
28a3a7eb3
|
342 |
spin_lock(&entry->lock); |
74c3cbe33
|
343 344 345 346 |
spin_lock(&hash_lock); if (tree->goner) { spin_unlock(&hash_lock); chunk->dead = 1; |
28a3a7eb3
|
347 |
spin_unlock(&entry->lock); |
e2a29943e
|
348 |
fsnotify_destroy_mark(entry, audit_tree_group); |
28a3a7eb3
|
349 |
fsnotify_put_mark(entry); |
74c3cbe33
|
350 351 352 353 354 355 356 357 358 359 360 361 |
return 0; } chunk->owners[0].index = (1U << 31); chunk->owners[0].owner = tree; get_tree(tree); list_add(&chunk->owners[0].list, &tree->chunks); if (!tree->root) { tree->root = chunk; list_add(&tree->same_root, &chunk->trees); } insert_hash(chunk); spin_unlock(&hash_lock); |
28a3a7eb3
|
362 |
spin_unlock(&entry->lock); |
b3e8692b4
|
363 |
fsnotify_put_mark(entry); /* drop initial reference */ |
74c3cbe33
|
364 365 366 367 368 369 |
return 0; } /* the first tagged inode becomes root of tree */ static int tag_chunk(struct inode *inode, struct audit_tree *tree) { |
e61ce8673
|
370 |
struct fsnotify_mark *old_entry, *chunk_entry; |
74c3cbe33
|
371 372 373 374 |
struct audit_tree *owner; struct audit_chunk *chunk, *old; struct node *p; int n; |
b1362edfe
|
375 376 |
old_entry = fsnotify_find_mark(&inode->i_fsnotify_marks, audit_tree_group); |
28a3a7eb3
|
377 |
if (!old_entry) |
74c3cbe33
|
378 |
return create_chunk(inode, tree); |
28a3a7eb3
|
379 |
old = container_of(old_entry, struct audit_chunk, mark); |
74c3cbe33
|
380 381 382 383 384 385 |
/* are we already there? */ spin_lock(&hash_lock); for (n = 0; n < old->count; n++) { if (old->owners[n].owner == tree) { spin_unlock(&hash_lock); |
28a3a7eb3
|
386 |
fsnotify_put_mark(old_entry); |
74c3cbe33
|
387 388 389 390 391 392 |
return 0; } } spin_unlock(&hash_lock); chunk = alloc_chunk(old->count + 1); |
b4c30aad3
|
393 |
if (!chunk) { |
28a3a7eb3
|
394 |
fsnotify_put_mark(old_entry); |
74c3cbe33
|
395 |
return -ENOMEM; |
b4c30aad3
|
396 |
} |
74c3cbe33
|
397 |
|
28a3a7eb3
|
398 |
chunk_entry = &chunk->mark; |
be29d20f3
|
399 |
mutex_lock(&old_entry->group->mark_mutex); |
28a3a7eb3
|
400 |
spin_lock(&old_entry->lock); |
6b3f05d24
|
401 402 403 404 |
/* * mark_mutex protects mark from getting detached and thus also from * mark->connector->inode getting NULL. */ |
43471d15d
|
405 |
if (!(old_entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) { |
28a3a7eb3
|
406 407 |
/* old_entry is being shot, lets just lie */ spin_unlock(&old_entry->lock); |
be29d20f3
|
408 |
mutex_unlock(&old_entry->group->mark_mutex); |
28a3a7eb3
|
409 |
fsnotify_put_mark(old_entry); |
7b1293234
|
410 |
fsnotify_put_mark(&chunk->mark); |
28a3a7eb3
|
411 412 |
return -ENOENT; } |
7b1293234
|
413 |
if (fsnotify_add_mark_locked(chunk_entry, |
86ffe245c
|
414 |
old_entry->connector->inode, NULL, 1)) { |
28a3a7eb3
|
415 |
spin_unlock(&old_entry->lock); |
be29d20f3
|
416 |
mutex_unlock(&old_entry->group->mark_mutex); |
0fe33aae0
|
417 |
fsnotify_put_mark(chunk_entry); |
28a3a7eb3
|
418 |
fsnotify_put_mark(old_entry); |
74c3cbe33
|
419 420 |
return -ENOSPC; } |
28a3a7eb3
|
421 422 423 |
/* even though we hold old_entry->lock, this is safe since chunk_entry->lock could NEVER have been grabbed before */ spin_lock(&chunk_entry->lock); |
74c3cbe33
|
424 |
spin_lock(&hash_lock); |
28a3a7eb3
|
425 426 |
/* we now hold old_entry->lock, chunk_entry->lock, and hash_lock */ |
74c3cbe33
|
427 428 429 |
if (tree->goner) { spin_unlock(&hash_lock); chunk->dead = 1; |
28a3a7eb3
|
430 431 |
spin_unlock(&chunk_entry->lock); spin_unlock(&old_entry->lock); |
be29d20f3
|
432 |
mutex_unlock(&old_entry->group->mark_mutex); |
28a3a7eb3
|
433 |
|
e2a29943e
|
434 |
fsnotify_destroy_mark(chunk_entry, audit_tree_group); |
28a3a7eb3
|
435 436 437 |
fsnotify_put_mark(chunk_entry); fsnotify_put_mark(old_entry); |
74c3cbe33
|
438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 |
return 0; } list_replace_init(&old->trees, &chunk->trees); for (n = 0, p = chunk->owners; n < old->count; n++, p++) { struct audit_tree *s = old->owners[n].owner; p->owner = s; p->index = old->owners[n].index; if (!s) /* result of fallback in untag */ continue; get_tree(s); list_replace_init(&old->owners[n].list, &p->list); } p->index = (chunk->count - 1) | (1U<<31); p->owner = tree; get_tree(tree); list_add(&p->list, &tree->chunks); list_replace_rcu(&old->hash, &chunk->hash); list_for_each_entry(owner, &chunk->trees, same_root) owner->root = chunk; old->dead = 1; if (!tree->root) { tree->root = chunk; list_add(&tree->same_root, &chunk->trees); } spin_unlock(&hash_lock); |
28a3a7eb3
|
463 464 |
spin_unlock(&chunk_entry->lock); spin_unlock(&old_entry->lock); |
be29d20f3
|
465 |
mutex_unlock(&old_entry->group->mark_mutex); |
e2a29943e
|
466 |
fsnotify_destroy_mark(old_entry, audit_tree_group); |
b3e8692b4
|
467 |
fsnotify_put_mark(chunk_entry); /* drop initial reference */ |
28a3a7eb3
|
468 |
fsnotify_put_mark(old_entry); /* pair to fsnotify_find mark_entry */ |
74c3cbe33
|
469 470 |
return 0; } |
2991dd2b0
|
471 |
static void audit_tree_log_remove_rule(struct audit_krule *rule) |
0644ec0cc
|
472 473 474 475 476 477 |
{ struct audit_buffer *ab; ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); if (unlikely(!ab)) return; |
c1e8f06d7
|
478 |
audit_log_format(ab, "op=remove_rule"); |
0644ec0cc
|
479 480 481 482 483 484 |
audit_log_format(ab, " dir="); audit_log_untrustedstring(ab, rule->tree->pathname); audit_log_key(ab, rule->filterkey); audit_log_format(ab, " list=%d res=1", rule->listnr); audit_log_end(ab); } |
74c3cbe33
|
485 486 487 488 |
static void kill_rules(struct audit_tree *tree) { struct audit_krule *rule, *next; struct audit_entry *entry; |
74c3cbe33
|
489 490 491 492 493 494 495 |
list_for_each_entry_safe(rule, next, &tree->rules, rlist) { entry = container_of(rule, struct audit_entry, rule); list_del_init(&rule->rlist); if (rule->tree) { /* not a half-baked one */ |
2991dd2b0
|
496 |
audit_tree_log_remove_rule(rule); |
34d99af52
|
497 498 |
if (entry->rule.exe) audit_remove_mark(entry->rule.exe); |
74c3cbe33
|
499 500 |
rule->tree = NULL; list_del_rcu(&entry->list); |
e45aa212e
|
501 |
list_del(&entry->rule.list); |
74c3cbe33
|
502 503 504 505 506 507 508 509 510 511 512 513 514 |
call_rcu(&entry->rcu, audit_free_rule_rcu); } } } /* * finish killing struct audit_tree */ static void prune_one(struct audit_tree *victim) { spin_lock(&hash_lock); while (!list_empty(&victim->chunks)) { struct node *p; |
74c3cbe33
|
515 516 |
p = list_entry(victim->chunks.next, struct node, list); |
74c3cbe33
|
517 |
|
8f7b0ba1c
|
518 |
untag_chunk(p); |
74c3cbe33
|
519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 |
} spin_unlock(&hash_lock); put_tree(victim); } /* trim the uncommitted chunks from tree */ static void trim_marked(struct audit_tree *tree) { struct list_head *p, *q; spin_lock(&hash_lock); if (tree->goner) { spin_unlock(&hash_lock); return; } /* reorder */ for (p = tree->chunks.next; p != &tree->chunks; p = q) { struct node *node = list_entry(p, struct node, list); q = p->next; if (node->index & (1U<<31)) { list_del_init(p); list_add(p, &tree->chunks); } } while (!list_empty(&tree->chunks)) { struct node *node; |
74c3cbe33
|
546 547 548 549 550 551 |
node = list_entry(tree->chunks.next, struct node, list); /* have we run out of marked? */ if (!(node->index & (1U<<31))) break; |
8f7b0ba1c
|
552 |
untag_chunk(node); |
74c3cbe33
|
553 554 555 556 557 558 559 560 561 562 563 564 565 |
} if (!tree->root && !tree->goner) { tree->goner = 1; spin_unlock(&hash_lock); mutex_lock(&audit_filter_mutex); kill_rules(tree); list_del_init(&tree->list); mutex_unlock(&audit_filter_mutex); prune_one(tree); } else { spin_unlock(&hash_lock); } } |
916d75761
|
566 |
static void audit_schedule_prune(void); |
74c3cbe33
|
567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 |
/* called with audit_filter_mutex */ int audit_remove_tree_rule(struct audit_krule *rule) { struct audit_tree *tree; tree = rule->tree; if (tree) { spin_lock(&hash_lock); list_del_init(&rule->rlist); if (list_empty(&tree->rules) && !tree->goner) { tree->root = NULL; list_del_init(&tree->same_root); tree->goner = 1; list_move(&tree->list, &prune_list); rule->tree = NULL; spin_unlock(&hash_lock); audit_schedule_prune(); return 1; } rule->tree = NULL; spin_unlock(&hash_lock); return 1; } return 0; } |
1f707137b
|
591 592 |
static int compare_root(struct vfsmount *mnt, void *arg) { |
f410ff655
|
593 594 |
return inode_to_key(d_backing_inode(mnt->mnt_root)) == (unsigned long)arg; |
1f707137b
|
595 |
} |
74c3cbe33
|
596 597 598 599 600 601 602 603 |
void audit_trim_trees(void) { struct list_head cursor; mutex_lock(&audit_filter_mutex); list_add(&cursor, &tree_list); while (cursor.next != &tree_list) { struct audit_tree *tree; |
98bc993f9
|
604 |
struct path path; |
74c3cbe33
|
605 606 |
struct vfsmount *root_mnt; struct node *node; |
74c3cbe33
|
607 608 609 610 611 612 613 |
int err; tree = container_of(cursor.next, struct audit_tree, list); get_tree(tree); list_del(&cursor); list_add(&cursor, &tree->list); mutex_unlock(&audit_filter_mutex); |
98bc993f9
|
614 |
err = kern_path(tree->pathname, 0, &path); |
74c3cbe33
|
615 616 |
if (err) goto skip_it; |
589ff870e
|
617 |
root_mnt = collect_mounts(&path); |
98bc993f9
|
618 |
path_put(&path); |
be34d1a3b
|
619 |
if (IS_ERR(root_mnt)) |
74c3cbe33
|
620 |
goto skip_it; |
74c3cbe33
|
621 622 |
spin_lock(&hash_lock); list_for_each_entry(node, &tree->chunks, list) { |
28a3a7eb3
|
623 |
struct audit_chunk *chunk = find_chunk(node); |
25985edce
|
624 |
/* this could be NULL if the watch is dying else where... */ |
74c3cbe33
|
625 |
node->index |= 1U<<31; |
f410ff655
|
626 627 628 |
if (iterate_mounts(compare_root, (void *)chunk_to_key(chunk), root_mnt)) |
1f707137b
|
629 |
node->index &= ~(1U<<31); |
74c3cbe33
|
630 631 632 |
} spin_unlock(&hash_lock); trim_marked(tree); |
74c3cbe33
|
633 634 |
drop_collected_mounts(root_mnt); skip_it: |
12b2f117f
|
635 |
put_tree(tree); |
74c3cbe33
|
636 637 638 639 640 |
mutex_lock(&audit_filter_mutex); } list_del(&cursor); mutex_unlock(&audit_filter_mutex); } |
74c3cbe33
|
641 642 643 644 645 |
int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op) { if (pathname[0] != '/' || rule->listnr != AUDIT_FILTER_EXIT || |
5af75d8d5
|
646 |
op != Audit_equal || |
74c3cbe33
|
647 648 649 650 651 652 653 654 655 656 657 658 |
rule->inode_f || rule->watch || rule->tree) return -EINVAL; rule->tree = alloc_tree(pathname); if (!rule->tree) return -ENOMEM; return 0; } void audit_put_tree(struct audit_tree *tree) { put_tree(tree); } |
1f707137b
|
659 660 |
static int tag_mount(struct vfsmount *mnt, void *arg) { |
3b362157b
|
661 |
return tag_chunk(d_backing_inode(mnt->mnt_root), arg); |
1f707137b
|
662 |
} |
f1aaf2622
|
663 664 665 666 667 668 669 |
/* * That gets run when evict_chunk() ends up needing to kill audit_tree. * Runs from a separate thread. */ static int prune_tree_thread(void *unused) { for (;;) { |
0bf676d1f
|
670 671 |
if (list_empty(&prune_list)) { set_current_state(TASK_INTERRUPTIBLE); |
f1aaf2622
|
672 |
schedule(); |
0bf676d1f
|
673 |
} |
f1aaf2622
|
674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 |
mutex_lock(&audit_cmd_mutex); mutex_lock(&audit_filter_mutex); while (!list_empty(&prune_list)) { struct audit_tree *victim; victim = list_entry(prune_list.next, struct audit_tree, list); list_del_init(&victim->list); mutex_unlock(&audit_filter_mutex); prune_one(victim); mutex_lock(&audit_filter_mutex); } mutex_unlock(&audit_filter_mutex); mutex_unlock(&audit_cmd_mutex); } return 0; } static int audit_launch_prune(void) { if (prune_thread) return 0; |
0bf676d1f
|
702 |
prune_thread = kthread_run(prune_tree_thread, NULL, |
f1aaf2622
|
703 704 705 706 707 |
"audit_prune_tree"); if (IS_ERR(prune_thread)) { pr_err("cannot start thread audit_prune_tree"); prune_thread = NULL; return -ENOMEM; |
f1aaf2622
|
708 |
} |
0bf676d1f
|
709 |
return 0; |
f1aaf2622
|
710 |
} |
74c3cbe33
|
711 712 713 714 |
/* called with audit_filter_mutex */ int audit_add_tree_rule(struct audit_krule *rule) { struct audit_tree *seed = rule->tree, *tree; |
98bc993f9
|
715 |
struct path path; |
1f707137b
|
716 |
struct vfsmount *mnt; |
74c3cbe33
|
717 |
int err; |
736f3203a
|
718 |
rule->tree = NULL; |
74c3cbe33
|
719 720 721 722 723 724 725 726 727 728 729 730 731 |
list_for_each_entry(tree, &tree_list, list) { if (!strcmp(seed->pathname, tree->pathname)) { put_tree(seed); rule->tree = tree; list_add(&rule->rlist, &tree->rules); return 0; } } tree = seed; list_add(&tree->list, &tree_list); list_add(&rule->rlist, &tree->rules); /* do not set rule->tree yet */ mutex_unlock(&audit_filter_mutex); |
f1aaf2622
|
732 733 734 735 736 |
if (unlikely(!prune_thread)) { err = audit_launch_prune(); if (err) goto Err; } |
98bc993f9
|
737 |
err = kern_path(tree->pathname, 0, &path); |
74c3cbe33
|
738 739 |
if (err) goto Err; |
589ff870e
|
740 |
mnt = collect_mounts(&path); |
98bc993f9
|
741 |
path_put(&path); |
be34d1a3b
|
742 743 |
if (IS_ERR(mnt)) { err = PTR_ERR(mnt); |
74c3cbe33
|
744 745 |
goto Err; } |
74c3cbe33
|
746 747 |
get_tree(tree); |
1f707137b
|
748 |
err = iterate_mounts(tag_mount, tree, mnt); |
74c3cbe33
|
749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 |
drop_collected_mounts(mnt); if (!err) { struct node *node; spin_lock(&hash_lock); list_for_each_entry(node, &tree->chunks, list) node->index &= ~(1U<<31); spin_unlock(&hash_lock); } else { trim_marked(tree); goto Err; } mutex_lock(&audit_filter_mutex); if (list_empty(&rule->rlist)) { put_tree(tree); return -ENOENT; } rule->tree = tree; put_tree(tree); return 0; Err: mutex_lock(&audit_filter_mutex); list_del_init(&tree->list); list_del_init(&tree->rules); put_tree(tree); return err; } int audit_tag_tree(char *old, char *new) { struct list_head cursor, barrier; int failed = 0; |
2096f759a
|
783 |
struct path path1, path2; |
74c3cbe33
|
784 |
struct vfsmount *tagged; |
74c3cbe33
|
785 |
int err; |
2096f759a
|
786 |
err = kern_path(new, 0, &path2); |
74c3cbe33
|
787 788 |
if (err) return err; |
2096f759a
|
789 790 |
tagged = collect_mounts(&path2); path_put(&path2); |
be34d1a3b
|
791 792 |
if (IS_ERR(tagged)) return PTR_ERR(tagged); |
74c3cbe33
|
793 |
|
2096f759a
|
794 |
err = kern_path(old, 0, &path1); |
74c3cbe33
|
795 796 797 798 |
if (err) { drop_collected_mounts(tagged); return err; } |
74c3cbe33
|
799 |
|
74c3cbe33
|
800 801 802 803 804 805 |
mutex_lock(&audit_filter_mutex); list_add(&barrier, &tree_list); list_add(&cursor, &barrier); while (cursor.next != &tree_list) { struct audit_tree *tree; |
2096f759a
|
806 |
int good_one = 0; |
74c3cbe33
|
807 808 809 810 811 812 |
tree = container_of(cursor.next, struct audit_tree, list); get_tree(tree); list_del(&cursor); list_add(&cursor, &tree->list); mutex_unlock(&audit_filter_mutex); |
2096f759a
|
813 814 815 816 |
err = kern_path(tree->pathname, 0, &path2); if (!err) { good_one = path_is_under(&path1, &path2); path_put(&path2); |
74c3cbe33
|
817 |
} |
2096f759a
|
818 |
if (!good_one) { |
74c3cbe33
|
819 820 821 822 |
put_tree(tree); mutex_lock(&audit_filter_mutex); continue; } |
74c3cbe33
|
823 |
|
1f707137b
|
824 |
failed = iterate_mounts(tag_mount, tree, tagged); |
74c3cbe33
|
825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 |
if (failed) { put_tree(tree); mutex_lock(&audit_filter_mutex); break; } mutex_lock(&audit_filter_mutex); spin_lock(&hash_lock); if (!tree->goner) { list_del(&tree->list); list_add(&tree->list, &tree_list); } spin_unlock(&hash_lock); put_tree(tree); } while (barrier.prev != &tree_list) { struct audit_tree *tree; tree = container_of(barrier.prev, struct audit_tree, list); get_tree(tree); list_del(&tree->list); list_add(&tree->list, &barrier); mutex_unlock(&audit_filter_mutex); if (!failed) { struct node *node; spin_lock(&hash_lock); list_for_each_entry(node, &tree->chunks, list) node->index &= ~(1U<<31); spin_unlock(&hash_lock); } else { trim_marked(tree); } put_tree(tree); mutex_lock(&audit_filter_mutex); } list_del(&barrier); list_del(&cursor); |
74c3cbe33
|
865 |
mutex_unlock(&audit_filter_mutex); |
2096f759a
|
866 |
path_put(&path1); |
74c3cbe33
|
867 868 869 |
drop_collected_mounts(tagged); return failed; } |
916d75761
|
870 871 872 |
static void audit_schedule_prune(void) { |
f1aaf2622
|
873 |
wake_up_process(prune_thread); |
916d75761
|
874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 |
} /* * ... and that one is done if evict_chunk() decides to delay until the end * of syscall. Runs synchronously. */ void audit_kill_trees(struct list_head *list) { mutex_lock(&audit_cmd_mutex); mutex_lock(&audit_filter_mutex); while (!list_empty(list)) { struct audit_tree *victim; victim = list_entry(list->next, struct audit_tree, list); kill_rules(victim); list_del_init(&victim->list); mutex_unlock(&audit_filter_mutex); prune_one(victim); mutex_lock(&audit_filter_mutex); } mutex_unlock(&audit_filter_mutex); mutex_unlock(&audit_cmd_mutex); |
74c3cbe33
|
901 902 903 904 905 |
} /* * Here comes the stuff asynchronous to auditctl operations */ |
74c3cbe33
|
906 907 908 |
static void evict_chunk(struct audit_chunk *chunk) { struct audit_tree *owner; |
916d75761
|
909 910 |
struct list_head *postponed = audit_killed_trees(); int need_prune = 0; |
74c3cbe33
|
911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 |
int n; if (chunk->dead) return; chunk->dead = 1; mutex_lock(&audit_filter_mutex); spin_lock(&hash_lock); while (!list_empty(&chunk->trees)) { owner = list_entry(chunk->trees.next, struct audit_tree, same_root); owner->goner = 1; owner->root = NULL; list_del_init(&owner->same_root); spin_unlock(&hash_lock); |
916d75761
|
926 927 928 929 930 931 932 |
if (!postponed) { kill_rules(owner); list_move(&owner->list, &prune_list); need_prune = 1; } else { list_move(&owner->list, postponed); } |
74c3cbe33
|
933 934 935 936 937 938 |
spin_lock(&hash_lock); } list_del_rcu(&chunk->hash); for (n = 0; n < chunk->count; n++) list_del_init(&chunk->owners[n].list); spin_unlock(&hash_lock); |
f1aaf2622
|
939 |
mutex_unlock(&audit_filter_mutex); |
916d75761
|
940 941 |
if (need_prune) audit_schedule_prune(); |
74c3cbe33
|
942 |
} |
3a9b16b40
|
943 |
static int audit_tree_handle_event(struct fsnotify_group *group, |
7053aee26
|
944 |
struct inode *to_tell, |
ce8f76fb7
|
945 |
struct fsnotify_mark *inode_mark, |
7053aee26
|
946 |
struct fsnotify_mark *vfsmount_mark, |
3cd5eca8d
|
947 |
u32 mask, const void *data, int data_type, |
9385a84d7
|
948 949 |
const unsigned char *file_name, u32 cookie, struct fsnotify_iter_info *iter_info) |
74c3cbe33
|
950 |
{ |
83c4c4b0a
|
951 |
return 0; |
28a3a7eb3
|
952 |
} |
74c3cbe33
|
953 |
|
e61ce8673
|
954 |
static void audit_tree_freeing_mark(struct fsnotify_mark *entry, struct fsnotify_group *group) |
28a3a7eb3
|
955 956 957 958 |
{ struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark); evict_chunk(chunk); |
b3e8692b4
|
959 960 961 962 963 964 |
/* * We are guaranteed to have at least one reference to the mark from * either the inode or the caller of fsnotify_destroy_mark(). */ BUG_ON(atomic_read(&entry->refcnt) < 1); |
74c3cbe33
|
965 |
} |
28a3a7eb3
|
966 967 |
static const struct fsnotify_ops audit_tree_ops = { .handle_event = audit_tree_handle_event, |
28a3a7eb3
|
968 |
.freeing_mark = audit_tree_freeing_mark, |
054c636e5
|
969 |
.free_mark = audit_tree_destroy_watch, |
74c3cbe33
|
970 971 972 973 974 |
}; static int __init audit_tree_init(void) { int i; |
0d2e2a1d0
|
975 |
audit_tree_group = fsnotify_alloc_group(&audit_tree_ops); |
28a3a7eb3
|
976 977 |
if (IS_ERR(audit_tree_group)) audit_panic("cannot initialize fsnotify group for rectree watches"); |
74c3cbe33
|
978 979 980 981 982 983 984 |
for (i = 0; i < HASH_SIZE; i++) INIT_LIST_HEAD(&chunk_hash_heads[i]); return 0; } __initcall(audit_tree_init); |