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2024-02-20 ea08eeccae9297f7aabd2ef7f0c2517ac4549acc 
 kernel/kernel/audit_tree.c
....@@ -25,9 +25,8 @@
2525 struct audit_chunk {
2626 	struct list_head hash;
2727 	unsigned long key;
28
-	struct fsnotify_mark mark;
28
+	struct fsnotify_mark *mark;
2929 	struct list_head trees;		/* with root here */
30
-	int dead;
3130 	int count;
3231 	atomic_long_t refs;
3332 	struct rcu_head head;
....@@ -38,13 +37,25 @@
3837 	} owners[];
3938 };
4039 
40
+struct audit_tree_mark {
41
+	struct fsnotify_mark mark;
42
+	struct audit_chunk *chunk;
43
+};
44
+
4145 static LIST_HEAD(tree_list);
4246 static LIST_HEAD(prune_list);
4347 static struct task_struct *prune_thread;
4448 
4549 /*
46
- * One struct chunk is attached to each inode of interest.
47
- * We replace struct chunk on tagging/untagging.
50
+ * One struct chunk is attached to each inode of interest through
51
+ * audit_tree_mark (fsnotify mark). We replace struct chunk on tagging /
52
+ * untagging, the mark is stable as long as there is chunk attached. The
53
+ * association between mark and chunk is protected by hash_lock and
54
+ * audit_tree_group->mark_mutex. Thus as long as we hold
55
+ * audit_tree_group->mark_mutex and check that the mark is alive by
56
+ * FSNOTIFY_MARK_FLAG_ATTACHED flag check, we are sure the mark points to
57
+ * the current chunk.
58
+ *
4859  * Rules have pointer to struct audit_tree.
4960  * Rules have struct list_head rlist forming a list of rules over
5061  * the same tree.
....@@ -63,8 +74,12 @@
6374  * tree is refcounted; one reference for "some rules on rules_list refer to
6475  * it", one for each chunk with pointer to it.
6576  *
66
- * chunk is refcounted by embedded fsnotify_mark + .refs (non-zero refcount
67
- * of watch contributes 1 to .refs).
77
+ * chunk is refcounted by embedded .refs. Mark associated with the chunk holds
78
+ * one chunk reference. This reference is dropped either when a mark is going
79
+ * to be freed (corresponding inode goes away) or when chunk attached to the
80
+ * mark gets replaced. This reference must be dropped using
81
+ * audit_mark_put_chunk() to make sure the reference is dropped only after RCU
82
+ * grace period as it protects RCU readers of the hash table.
6883  *
6984  * node.index allows to get from node.list to containing chunk.
7085  * MSB of that sucker is stolen to mark taggings that we might have to
....@@ -73,6 +88,7 @@
7388  */
7489 
7590 static struct fsnotify_group *audit_tree_group;
91
+static struct kmem_cache *audit_tree_mark_cachep __read_mostly;
7692 
7793 static struct audit_tree *alloc_tree(const char *s)
7894 {
....@@ -132,20 +148,49 @@
132148 	audit_put_chunk(chunk);
133149 }
134150 
135
-static void audit_tree_destroy_watch(struct fsnotify_mark *entry)
151
+/*
152
+ * Drop reference to the chunk that was held by the mark. This is the reference
153
+ * that gets dropped after we've removed the chunk from the hash table and we
154
+ * use it to make sure chunk cannot be freed before RCU grace period expires.
155
+ */
156
+static void audit_mark_put_chunk(struct audit_chunk *chunk)
136157 {
137
-	struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark);
138158 	call_rcu(&chunk->head, __put_chunk);
159
+}
160
+
161
+static inline struct audit_tree_mark *audit_mark(struct fsnotify_mark *mark)
162
+{
163
+	return container_of(mark, struct audit_tree_mark, mark);
164
+}
165
+
166
+static struct audit_chunk *mark_chunk(struct fsnotify_mark *mark)
167
+{
168
+	return audit_mark(mark)->chunk;
169
+}
170
+
171
+static void audit_tree_destroy_watch(struct fsnotify_mark *mark)
172
+{
173
+	kmem_cache_free(audit_tree_mark_cachep, audit_mark(mark));
174
+}
175
+
176
+static struct fsnotify_mark *alloc_mark(void)
177
+{
178
+	struct audit_tree_mark *amark;
179
+
180
+	amark = kmem_cache_zalloc(audit_tree_mark_cachep, GFP_KERNEL);
181
+	if (!amark)
182
+		return NULL;
183
+	fsnotify_init_mark(&amark->mark, audit_tree_group);
184
+	amark->mark.mask = FS_IN_IGNORED;
185
+	return &amark->mark;
139186 }
140187 
141188 static struct audit_chunk *alloc_chunk(int count)
142189 {
143190 	struct audit_chunk *chunk;
144
-	size_t size;
145191 	int i;
146192 
147
-	size = offsetof(struct audit_chunk, owners) + count * sizeof(struct node);
148
-	chunk = kzalloc(size, GFP_KERNEL);
193
+	chunk = kzalloc(struct_size(chunk, owners, count), GFP_KERNEL);
149194 	if (!chunk)
150195 		return NULL;
151196 
....@@ -157,8 +202,6 @@
157202 		INIT_LIST_HEAD(&chunk->owners[i].list);
158203 		chunk->owners[i].index = i;
159204 	}
160
-	fsnotify_init_mark(&chunk->mark, audit_tree_group);
161
-	chunk->mark.mask = FS_IN_IGNORED;
162205 	return chunk;
163206 }
164207 
....@@ -179,13 +222,17 @@
179222 	return chunk_hash_heads + n % HASH_SIZE;
180223 }
181224 
182
-/* hash_lock & entry->lock is held by caller */
225
+/* hash_lock & mark->group->mark_mutex is held by caller */
183226 static void insert_hash(struct audit_chunk *chunk)
184227 {
185228 	struct list_head *list;
186229 
187
-	if (!(chunk->mark.flags & FSNOTIFY_MARK_FLAG_ATTACHED))
188
-		return;
230
+	/*
231
+	 * Make sure chunk is fully initialized before making it visible in the
232
+	 * hash. Pairs with a data dependency barrier in READ_ONCE() in
233
+	 * audit_tree_lookup().
234
+	 */
235
+	smp_wmb();
189236 	WARN_ON_ONCE(!chunk->key);
190237 	list = chunk_hash(chunk->key);
191238 	list_add_rcu(&chunk->hash, list);
....@@ -199,7 +246,11 @@
199246 	struct audit_chunk *p;
200247 
201248 	list_for_each_entry_rcu(p, list, hash) {
202
-		if (p->key == key) {
249
+		/*
250
+		 * We use a data dependency barrier in READ_ONCE() to make sure
251
+		 * the chunk we see is fully initialized.
252
+		 */
253
+		if (READ_ONCE(p->key) == key) {
203254 			atomic_long_inc(&p->refs);
204255 			return p;
205256 		}
....@@ -225,100 +276,56 @@
225276 	return container_of(p, struct audit_chunk, owners[0]);
226277 }
227278 
228
-static void untag_chunk(struct node *p)
279
+static void replace_mark_chunk(struct fsnotify_mark *mark,
280
+			       struct audit_chunk *chunk)
229281 {
230
-	struct audit_chunk *chunk = find_chunk(p);
231
-	struct fsnotify_mark *entry = &chunk->mark;
232
-	struct audit_chunk *new = NULL;
282
+	struct audit_chunk *old;
283
+
284
+	assert_spin_locked(&hash_lock);
285
+	old = mark_chunk(mark);
286
+	audit_mark(mark)->chunk = chunk;
287
+	if (chunk)
288
+		chunk->mark = mark;
289
+	if (old)
290
+		old->mark = NULL;
291
+}
292
+
293
+static void replace_chunk(struct audit_chunk *new, struct audit_chunk *old)
294
+{
233295 	struct audit_tree *owner;
234
-	int size = chunk->count - 1;
235296 	int i, j;
236297 
237
-	fsnotify_get_mark(entry);
238
-
239
-	spin_unlock(&hash_lock);
240
-
241
-	if (size)
242
-		new = alloc_chunk(size);
243
-
244
-	mutex_lock(&entry->group->mark_mutex);
245
-	spin_lock(&entry->lock);
246
-	/*
247
-	 * mark_mutex protects mark from getting detached and thus also from
248
-	 * mark->connector->obj getting NULL.
249
-	 */
250
-	if (chunk->dead || !(entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) {
251
-		spin_unlock(&entry->lock);
252
-		mutex_unlock(&entry->group->mark_mutex);
253
-		if (new)
254
-			fsnotify_put_mark(&new->mark);
255
-		goto out;
256
-	}
257
-
258
-	owner = p->owner;
259
-
260
-	if (!size) {
261
-		chunk->dead = 1;
262
-		spin_lock(&hash_lock);
263
-		list_del_init(&chunk->trees);
264
-		if (owner->root == chunk)
265
-			owner->root = NULL;
266
-		list_del_init(&p->list);
267
-		list_del_rcu(&chunk->hash);
268
-		spin_unlock(&hash_lock);
269
-		spin_unlock(&entry->lock);
270
-		mutex_unlock(&entry->group->mark_mutex);
271
-		fsnotify_destroy_mark(entry, audit_tree_group);
272
-		goto out;
273
-	}
274
-
275
-	if (!new)
276
-		goto Fallback;
277
-
278
-	if (fsnotify_add_mark_locked(&new->mark, entry->connector->obj,
279
-				     FSNOTIFY_OBJ_TYPE_INODE, 1)) {
280
-		fsnotify_put_mark(&new->mark);
281
-		goto Fallback;
282
-	}
283
-
284
-	chunk->dead = 1;
285
-	spin_lock(&hash_lock);
286
-	new->key = chunk->key;
287
-	list_replace_init(&chunk->trees, &new->trees);
288
-	if (owner->root == chunk) {
289
-		list_del_init(&owner->same_root);
290
-		owner->root = NULL;
291
-	}
292
-
293
-	for (i = j = 0; j <= size; i++, j++) {
294
-		struct audit_tree *s;
295
-		if (&chunk->owners[j] == p) {
296
-			list_del_init(&p->list);
298
+	new->key = old->key;
299
+	list_splice_init(&old->trees, &new->trees);
300
+	list_for_each_entry(owner, &new->trees, same_root)
301
+		owner->root = new;
302
+	for (i = j = 0; j < old->count; i++, j++) {
303
+		if (!old->owners[j].owner) {
297304 			i--;
298305 			continue;
299306 		}
300
-		s = chunk->owners[j].owner;
301
-		new->owners[i].owner = s;
302
-		new->owners[i].index = chunk->owners[j].index - j + i;
303
-		if (!s) /* result of earlier fallback */
307
+		owner = old->owners[j].owner;
308
+		new->owners[i].owner = owner;
309
+		new->owners[i].index = old->owners[j].index - j + i;
310
+		if (!owner) /* result of earlier fallback */
304311 			continue;
305
-		get_tree(s);
306
-		list_replace_init(&chunk->owners[j].list, &new->owners[i].list);
312
+		get_tree(owner);
313
+		list_replace_init(&old->owners[j].list, &new->owners[i].list);
307314 	}
315
+	replace_mark_chunk(old->mark, new);
316
+	/*
317
+	 * Make sure chunk is fully initialized before making it visible in the
318
+	 * hash. Pairs with a data dependency barrier in READ_ONCE() in
319
+	 * audit_tree_lookup().
320
+	 */
321
+	smp_wmb();
322
+	list_replace_rcu(&old->hash, &new->hash);
323
+}
308324 
309
-	list_replace_rcu(&chunk->hash, &new->hash);
310
-	list_for_each_entry(owner, &new->trees, same_root)
311
-		owner->root = new;
312
-	spin_unlock(&hash_lock);
313
-	spin_unlock(&entry->lock);
314
-	mutex_unlock(&entry->group->mark_mutex);
315
-	fsnotify_destroy_mark(entry, audit_tree_group);
316
-	fsnotify_put_mark(&new->mark);	/* drop initial reference */
317
-	goto out;
325
+static void remove_chunk_node(struct audit_chunk *chunk, struct node *p)
326
+{
327
+	struct audit_tree *owner = p->owner;
318328 
319
-Fallback:
320
-	// do the best we can
321
-	spin_lock(&hash_lock);
322329 	if (owner->root == chunk) {
323330 		list_del_init(&owner->same_root);
324331 		owner->root = NULL;
....@@ -326,37 +333,102 @@
326333 	list_del_init(&p->list);
327334 	p->owner = NULL;
328335 	put_tree(owner);
329
-	spin_unlock(&hash_lock);
330
-	spin_unlock(&entry->lock);
331
-	mutex_unlock(&entry->group->mark_mutex);
332
-out:
333
-	fsnotify_put_mark(entry);
334
-	spin_lock(&hash_lock);
335336 }
336337 
338
+static int chunk_count_trees(struct audit_chunk *chunk)
339
+{
340
+	int i;
341
+	int ret = 0;
342
+
343
+	for (i = 0; i < chunk->count; i++)
344
+		if (chunk->owners[i].owner)
345
+			ret++;
346
+	return ret;
347
+}
348
+
349
+static void untag_chunk(struct audit_chunk *chunk, struct fsnotify_mark *mark)
350
+{
351
+	struct audit_chunk *new;
352
+	int size;
353
+
354
+	mutex_lock(&audit_tree_group->mark_mutex);
355
+	/*
356
+	 * mark_mutex stabilizes chunk attached to the mark so we can check
357
+	 * whether it didn't change while we've dropped hash_lock.
358
+	 */
359
+	if (!(mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED) ||
360
+	    mark_chunk(mark) != chunk)
361
+		goto out_mutex;
362
+
363
+	size = chunk_count_trees(chunk);
364
+	if (!size) {
365
+		spin_lock(&hash_lock);
366
+		list_del_init(&chunk->trees);
367
+		list_del_rcu(&chunk->hash);
368
+		replace_mark_chunk(mark, NULL);
369
+		spin_unlock(&hash_lock);
370
+		fsnotify_detach_mark(mark);
371
+		mutex_unlock(&audit_tree_group->mark_mutex);
372
+		audit_mark_put_chunk(chunk);
373
+		fsnotify_free_mark(mark);
374
+		return;
375
+	}
376
+
377
+	new = alloc_chunk(size);
378
+	if (!new)
379
+		goto out_mutex;
380
+
381
+	spin_lock(&hash_lock);
382
+	/*
383
+	 * This has to go last when updating chunk as once replace_chunk() is
384
+	 * called, new RCU readers can see the new chunk.
385
+	 */
386
+	replace_chunk(new, chunk);
387
+	spin_unlock(&hash_lock);
388
+	mutex_unlock(&audit_tree_group->mark_mutex);
389
+	audit_mark_put_chunk(chunk);
390
+	return;
391
+
392
+out_mutex:
393
+	mutex_unlock(&audit_tree_group->mark_mutex);
394
+}
395
+
396
+/* Call with group->mark_mutex held, releases it */
337397 static int create_chunk(struct inode *inode, struct audit_tree *tree)
338398 {
339
-	struct fsnotify_mark *entry;
399
+	struct fsnotify_mark *mark;
340400 	struct audit_chunk *chunk = alloc_chunk(1);
341
-	if (!chunk)
342
-		return -ENOMEM;
343401 
344
-	entry = &chunk->mark;
345
-	if (fsnotify_add_inode_mark(entry, inode, 0)) {
346
-		fsnotify_put_mark(entry);
402
+	if (!chunk) {
403
+		mutex_unlock(&audit_tree_group->mark_mutex);
404
+		return -ENOMEM;
405
+	}
406
+
407
+	mark = alloc_mark();
408
+	if (!mark) {
409
+		mutex_unlock(&audit_tree_group->mark_mutex);
410
+		kfree(chunk);
411
+		return -ENOMEM;
412
+	}
413
+
414
+	if (fsnotify_add_inode_mark_locked(mark, inode, 0)) {
415
+		mutex_unlock(&audit_tree_group->mark_mutex);
416
+		fsnotify_put_mark(mark);
417
+		kfree(chunk);
347418 		return -ENOSPC;
348419 	}
349420 
350
-	spin_lock(&entry->lock);
351421 	spin_lock(&hash_lock);
352422 	if (tree->goner) {
353423 		spin_unlock(&hash_lock);
354
-		chunk->dead = 1;
355
-		spin_unlock(&entry->lock);
356
-		fsnotify_destroy_mark(entry, audit_tree_group);
357
-		fsnotify_put_mark(entry);
424
+		fsnotify_detach_mark(mark);
425
+		mutex_unlock(&audit_tree_group->mark_mutex);
426
+		fsnotify_free_mark(mark);
427
+		fsnotify_put_mark(mark);
428
+		kfree(chunk);
358429 		return 0;
359430 	}
431
+	replace_mark_chunk(mark, chunk);
360432 	chunk->owners[0].index = (1U << 31);
361433 	chunk->owners[0].owner = tree;
362434 	get_tree(tree);
....@@ -366,35 +438,48 @@
366438 		list_add(&tree->same_root, &chunk->trees);
367439 	}
368440 	chunk->key = inode_to_key(inode);
441
+	/*
442
+	 * Inserting into the hash table has to go last as once we do that RCU
443
+	 * readers can see the chunk.
444
+	 */
369445 	insert_hash(chunk);
370446 	spin_unlock(&hash_lock);
371
-	spin_unlock(&entry->lock);
372
-	fsnotify_put_mark(entry);	/* drop initial reference */
447
+	mutex_unlock(&audit_tree_group->mark_mutex);
448
+	/*
449
+	 * Drop our initial reference. When mark we point to is getting freed,
450
+	 * we get notification through ->freeing_mark callback and cleanup
451
+	 * chunk pointing to this mark.
452
+	 */
453
+	fsnotify_put_mark(mark);
373454 	return 0;
374455 }
375456 
376457 /* the first tagged inode becomes root of tree */
377458 static int tag_chunk(struct inode *inode, struct audit_tree *tree)
378459 {
379
-	struct fsnotify_mark *old_entry, *chunk_entry;
380
-	struct audit_tree *owner;
460
+	struct fsnotify_mark *mark;
381461 	struct audit_chunk *chunk, *old;
382462 	struct node *p;
383463 	int n;
384464 
385
-	old_entry = fsnotify_find_mark(&inode->i_fsnotify_marks,
386
-				       audit_tree_group);
387
-	if (!old_entry)
465
+	mutex_lock(&audit_tree_group->mark_mutex);
466
+	mark = fsnotify_find_mark(&inode->i_fsnotify_marks, audit_tree_group);
467
+	if (!mark)
388468 		return create_chunk(inode, tree);
389469 
390
-	old = container_of(old_entry, struct audit_chunk, mark);
391
-
470
+	/*
471
+	 * Found mark is guaranteed to be attached and mark_mutex protects mark
472
+	 * from getting detached and thus it makes sure there is chunk attached
473
+	 * to the mark.
474
+	 */
392475 	/* are we already there? */
393476 	spin_lock(&hash_lock);
477
+	old = mark_chunk(mark);
394478 	for (n = 0; n < old->count; n++) {
395479 		if (old->owners[n].owner == tree) {
396480 			spin_unlock(&hash_lock);
397
-			fsnotify_put_mark(old_entry);
481
+			mutex_unlock(&audit_tree_group->mark_mutex);
482
+			fsnotify_put_mark(mark);
398483 			return 0;
399484 		}
400485 	}
....@@ -402,105 +487,59 @@
402487 
403488 	chunk = alloc_chunk(old->count + 1);
404489 	if (!chunk) {
405
-		fsnotify_put_mark(old_entry);
490
+		mutex_unlock(&audit_tree_group->mark_mutex);
491
+		fsnotify_put_mark(mark);
406492 		return -ENOMEM;
407493 	}
408494 
409
-	chunk_entry = &chunk->mark;
410
-
411
-	mutex_lock(&old_entry->group->mark_mutex);
412
-	spin_lock(&old_entry->lock);
413
-	/*
414
-	 * mark_mutex protects mark from getting detached and thus also from
415
-	 * mark->connector->obj getting NULL.
416
-	 */
417
-	if (!(old_entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) {
418
-		/* old_entry is being shot, lets just lie */
419
-		spin_unlock(&old_entry->lock);
420
-		mutex_unlock(&old_entry->group->mark_mutex);
421
-		fsnotify_put_mark(old_entry);
422
-		fsnotify_put_mark(&chunk->mark);
423
-		return -ENOENT;
424
-	}
425
-
426
-	if (fsnotify_add_mark_locked(chunk_entry, old_entry->connector->obj,
427
-				     FSNOTIFY_OBJ_TYPE_INODE, 1)) {
428
-		spin_unlock(&old_entry->lock);
429
-		mutex_unlock(&old_entry->group->mark_mutex);
430
-		fsnotify_put_mark(chunk_entry);
431
-		fsnotify_put_mark(old_entry);
432
-		return -ENOSPC;
433
-	}
434
-
435
-	/* even though we hold old_entry->lock, this is safe since chunk_entry->lock could NEVER have been grabbed before */
436
-	spin_lock(&chunk_entry->lock);
437495 	spin_lock(&hash_lock);
438
-
439
-	/* we now hold old_entry->lock, chunk_entry->lock, and hash_lock */
440496 	if (tree->goner) {
441497 		spin_unlock(&hash_lock);
442
-		chunk->dead = 1;
443
-		spin_unlock(&chunk_entry->lock);
444
-		spin_unlock(&old_entry->lock);
445
-		mutex_unlock(&old_entry->group->mark_mutex);
446
-
447
-		fsnotify_destroy_mark(chunk_entry, audit_tree_group);
448
-
449
-		fsnotify_put_mark(chunk_entry);
450
-		fsnotify_put_mark(old_entry);
498
+		mutex_unlock(&audit_tree_group->mark_mutex);
499
+		fsnotify_put_mark(mark);
500
+		kfree(chunk);
451501 		return 0;
452502 	}
453
-	chunk->key = old->key;
454
-	list_replace_init(&old->trees, &chunk->trees);
455
-	for (n = 0, p = chunk->owners; n < old->count; n++, p++) {
456
-		struct audit_tree *s = old->owners[n].owner;
457
-		p->owner = s;
458
-		p->index = old->owners[n].index;
459
-		if (!s) /* result of fallback in untag */
460
-			continue;
461
-		get_tree(s);
462
-		list_replace_init(&old->owners[n].list, &p->list);
463
-	}
503
+	p = &chunk->owners[chunk->count - 1];
464504 	p->index = (chunk->count - 1) | (1U<<31);
465505 	p->owner = tree;
466506 	get_tree(tree);
467507 	list_add(&p->list, &tree->chunks);
468
-	list_replace_rcu(&old->hash, &chunk->hash);
469
-	list_for_each_entry(owner, &chunk->trees, same_root)
470
-		owner->root = chunk;
471
-	old->dead = 1;
472508 	if (!tree->root) {
473509 		tree->root = chunk;
474510 		list_add(&tree->same_root, &chunk->trees);
475511 	}
512
+	/*
513
+	 * This has to go last when updating chunk as once replace_chunk() is
514
+	 * called, new RCU readers can see the new chunk.
515
+	 */
516
+	replace_chunk(chunk, old);
476517 	spin_unlock(&hash_lock);
477
-	spin_unlock(&chunk_entry->lock);
478
-	spin_unlock(&old_entry->lock);
479
-	mutex_unlock(&old_entry->group->mark_mutex);
480
-	fsnotify_destroy_mark(old_entry, audit_tree_group);
481
-	fsnotify_put_mark(chunk_entry);	/* drop initial reference */
482
-	fsnotify_put_mark(old_entry); /* pair to fsnotify_find mark_entry */
518
+	mutex_unlock(&audit_tree_group->mark_mutex);
519
+	fsnotify_put_mark(mark); /* pair to fsnotify_find_mark */
520
+	audit_mark_put_chunk(old);
521
+
483522 	return 0;
484523 }
485524 
486
-static void audit_tree_log_remove_rule(struct audit_krule *rule)
525
+static void audit_tree_log_remove_rule(struct audit_context *context,
526
+				       struct audit_krule *rule)
487527 {
488528 	struct audit_buffer *ab;
489529 
490530 	if (!audit_enabled)
491531 		return;
492
-	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
532
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
493533 	if (unlikely(!ab))
494534 		return;
495
-	audit_log_format(ab, "op=remove_rule");
496
-	audit_log_format(ab, " dir=");
535
+	audit_log_format(ab, "op=remove_rule dir=");
497536 	audit_log_untrustedstring(ab, rule->tree->pathname);
498537 	audit_log_key(ab, rule->filterkey);
499538 	audit_log_format(ab, " list=%d res=1", rule->listnr);
500539 	audit_log_end(ab);
501540 }
502541 
503
-static void kill_rules(struct audit_tree *tree)
542
+static void kill_rules(struct audit_context *context, struct audit_tree *tree)
504543 {
505544 	struct audit_krule *rule, *next;
506545 	struct audit_entry *entry;
....@@ -511,7 +550,7 @@
511550 		list_del_init(&rule->rlist);
512551 		if (rule->tree) {
513552 			/* not a half-baked one */
514
-			audit_tree_log_remove_rule(rule);
553
+			audit_tree_log_remove_rule(context, rule);
515554 			if (entry->rule.exe)
516555 				audit_remove_mark(entry->rule.exe);
517556 			rule->tree = NULL;
....@@ -523,19 +562,45 @@
523562 }
524563 
525564 /*
526
- * finish killing struct audit_tree
565
+ * Remove tree from chunks. If 'tagged' is set, remove tree only from tagged
566
+ * chunks. The function expects tagged chunks are all at the beginning of the
567
+ * chunks list.
527568  */
528
-static void prune_one(struct audit_tree *victim)
569
+static void prune_tree_chunks(struct audit_tree *victim, bool tagged)
529570 {
530571 	spin_lock(&hash_lock);
531572 	while (!list_empty(&victim->chunks)) {
532573 		struct node *p;
574
+		struct audit_chunk *chunk;
575
+		struct fsnotify_mark *mark;
533576 
534
-		p = list_entry(victim->chunks.next, struct node, list);
577
+		p = list_first_entry(&victim->chunks, struct node, list);
578
+		/* have we run out of marked? */
579
+		if (tagged && !(p->index & (1U<<31)))
580
+			break;
581
+		chunk = find_chunk(p);
582
+		mark = chunk->mark;
583
+		remove_chunk_node(chunk, p);
584
+		/* Racing with audit_tree_freeing_mark()? */
585
+		if (!mark)
586
+			continue;
587
+		fsnotify_get_mark(mark);
588
+		spin_unlock(&hash_lock);
535589 
536
-		untag_chunk(p);
590
+		untag_chunk(chunk, mark);
591
+		fsnotify_put_mark(mark);
592
+
593
+		spin_lock(&hash_lock);
537594 	}
538595 	spin_unlock(&hash_lock);
596
+}
597
+
598
+/*
599
+ * finish killing struct audit_tree
600
+ */
601
+static void prune_one(struct audit_tree *victim)
602
+{
603
+	prune_tree_chunks(victim, false);
539604 	put_tree(victim);
540605 }
541606 
....@@ -558,23 +623,16 @@
558623 			list_add(p, &tree->chunks);
559624 		}
560625 	}
626
+	spin_unlock(&hash_lock);
561627 
562
-	while (!list_empty(&tree->chunks)) {
563
-		struct node *node;
628
+	prune_tree_chunks(tree, true);
564629 
565
-		node = list_entry(tree->chunks.next, struct node, list);
566
-
567
-		/* have we run out of marked? */
568
-		if (!(node->index & (1U<<31)))
569
-			break;
570
-
571
-		untag_chunk(node);
572
-	}
630
+	spin_lock(&hash_lock);
573631 	if (!tree->root && !tree->goner) {
574632 		tree->goner = 1;
575633 		spin_unlock(&hash_lock);
576634 		mutex_lock(&audit_filter_mutex);
577
-		kill_rules(tree);
635
+		kill_rules(audit_context(), tree);
578636 		list_del_init(&tree->list);
579637 		mutex_unlock(&audit_filter_mutex);
580638 		prune_one(tree);
....@@ -914,8 +972,10 @@
914972  * ... and that one is done if evict_chunk() decides to delay until the end
915973  * of syscall.  Runs synchronously.
916974  */
917
-void audit_kill_trees(struct list_head *list)
975
+void audit_kill_trees(struct audit_context *context)
918976 {
977
+	struct list_head *list = &context->killed_trees;
978
+
919979 	audit_ctl_lock();
920980 	mutex_lock(&audit_filter_mutex);
921981 
....@@ -923,7 +983,7 @@
923983 		struct audit_tree *victim;
924984 
925985 		victim = list_entry(list->next, struct audit_tree, list);
926
-		kill_rules(victim);
986
+		kill_rules(context, victim);
927987 		list_del_init(&victim->list);
928988 
929989 		mutex_unlock(&audit_filter_mutex);
....@@ -948,10 +1008,6 @@
9481008 	int need_prune = 0;
9491009 	int n;
9501010 
951
-	if (chunk->dead)
952
-		return;
953
-
954
-	chunk->dead = 1;
9551011 	mutex_lock(&audit_filter_mutex);
9561012 	spin_lock(&hash_lock);
9571013 	while (!list_empty(&chunk->trees)) {
....@@ -962,7 +1018,7 @@
9621018 		list_del_init(&owner->same_root);
9631019 		spin_unlock(&hash_lock);
9641020 		if (!postponed) {
965
-			kill_rules(owner);
1021
+			kill_rules(audit_context(), owner);
9661022 			list_move(&owner->list, &prune_list);
9671023 			need_prune = 1;
9681024 		} else {
....@@ -979,30 +1035,38 @@
9791035 		audit_schedule_prune();
9801036 }
9811037 
982
-static int audit_tree_handle_event(struct fsnotify_group *group,
983
-				   struct inode *to_tell,
984
-				   u32 mask, const void *data, int data_type,
985
-				   const unsigned char *file_name, u32 cookie,
986
-				   struct fsnotify_iter_info *iter_info)
1038
+static int audit_tree_handle_event(struct fsnotify_mark *mark, u32 mask,
1039
+				   struct inode *inode, struct inode *dir,
1040
+				   const struct qstr *file_name, u32 cookie)
9871041 {
9881042 	return 0;
9891043 }
9901044 
991
-static void audit_tree_freeing_mark(struct fsnotify_mark *entry, struct fsnotify_group *group)
1045
+static void audit_tree_freeing_mark(struct fsnotify_mark *mark,
1046
+				    struct fsnotify_group *group)
9921047 {
993
-	struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark);
1048
+	struct audit_chunk *chunk;
9941049 
995
-	evict_chunk(chunk);
1050
+	mutex_lock(&mark->group->mark_mutex);
1051
+	spin_lock(&hash_lock);
1052
+	chunk = mark_chunk(mark);
1053
+	replace_mark_chunk(mark, NULL);
1054
+	spin_unlock(&hash_lock);
1055
+	mutex_unlock(&mark->group->mark_mutex);
1056
+	if (chunk) {
1057
+		evict_chunk(chunk);
1058
+		audit_mark_put_chunk(chunk);
1059
+	}
9961060 
9971061 	/*
9981062 	 * We are guaranteed to have at least one reference to the mark from
9991063 	 * either the inode or the caller of fsnotify_destroy_mark().
10001064 	 */
1001
-	BUG_ON(refcount_read(&entry->refcnt) < 1);
1065
+	BUG_ON(refcount_read(&mark->refcnt) < 1);
10021066 }
10031067 
10041068 static const struct fsnotify_ops audit_tree_ops = {
1005
-	.handle_event = audit_tree_handle_event,
1069
+	.handle_inode_event = audit_tree_handle_event,
10061070 	.freeing_mark = audit_tree_freeing_mark,
10071071 	.free_mark = audit_tree_destroy_watch,
10081072 };
....@@ -1011,6 +1075,8 @@
10111075 {
10121076 	int i;
10131077 
1078
+	audit_tree_mark_cachep = KMEM_CACHE(audit_tree_mark, SLAB_PANIC);
1079
+
10141080 	audit_tree_group = fsnotify_alloc_group(&audit_tree_ops);
10151081 	if (IS_ERR(audit_tree_group))
10161082 		audit_panic("cannot initialize fsnotify group for rectree watches");