1#include <linux/fanotify.h>
2#include <linux/fcntl.h>
3#include <linux/file.h>
4#include <linux/fs.h>
5#include <linux/anon_inodes.h>
6#include <linux/fsnotify_backend.h>
7#include <linux/init.h>
8#include <linux/mount.h>
9#include <linux/namei.h>
10#include <linux/poll.h>
11#include <linux/security.h>
12#include <linux/syscalls.h>
13#include <linux/slab.h>
14#include <linux/types.h>
15#include <linux/uaccess.h>
16
17#include <asm/ioctls.h>
18
19#define FANOTIFY_DEFAULT_MAX_EVENTS 16384
20#define FANOTIFY_DEFAULT_MAX_MARKS 8192
21#define FANOTIFY_DEFAULT_MAX_LISTENERS 128
22
23extern const struct fsnotify_ops fanotify_fsnotify_ops;
24
25static struct kmem_cache *fanotify_mark_cache __read_mostly;
26static struct kmem_cache *fanotify_response_event_cache __read_mostly;
27
28struct fanotify_response_event {
29 struct list_head list;
30 __s32 fd;
31 struct fsnotify_event *event;
32};
33
34
35
36
37
38
39
40
41static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
42 size_t count)
43{
44 BUG_ON(!mutex_is_locked(&group->notification_mutex));
45
46 pr_debug("%s: group=%p count=%zd\n", __func__, group, count);
47
48 if (fsnotify_notify_queue_is_empty(group))
49 return NULL;
50
51 if (FAN_EVENT_METADATA_LEN > count)
52 return ERR_PTR(-EINVAL);
53
54
55
56 return fsnotify_remove_notify_event(group);
57}
58
59static int create_fd(struct fsnotify_group *group, struct fsnotify_event *event)
60{
61 int client_fd;
62 struct dentry *dentry;
63 struct vfsmount *mnt;
64 struct file *new_file;
65
66 pr_debug("%s: group=%p event=%p\n", __func__, group, event);
67
68 client_fd = get_unused_fd();
69 if (client_fd < 0)
70 return client_fd;
71
72 if (event->data_type != FSNOTIFY_EVENT_PATH) {
73 WARN_ON(1);
74 put_unused_fd(client_fd);
75 return -EINVAL;
76 }
77
78
79
80
81
82 dentry = dget(event->path.dentry);
83 mnt = mntget(event->path.mnt);
84
85
86 if (dentry && mnt)
87 new_file = dentry_open(dentry, mnt,
88 group->fanotify_data.f_flags | FMODE_NONOTIFY,
89 current_cred());
90 else
91 new_file = ERR_PTR(-EOVERFLOW);
92 if (IS_ERR(new_file)) {
93
94
95
96
97
98
99
100 put_unused_fd(client_fd);
101 client_fd = PTR_ERR(new_file);
102 } else {
103 fd_install(client_fd, new_file);
104 }
105
106 return client_fd;
107}
108
109static int fill_event_metadata(struct fsnotify_group *group,
110 struct fanotify_event_metadata *metadata,
111 struct fsnotify_event *event)
112{
113 int ret = 0;
114
115 pr_debug("%s: group=%p metadata=%p event=%p\n", __func__,
116 group, metadata, event);
117
118 metadata->event_len = FAN_EVENT_METADATA_LEN;
119 metadata->metadata_len = FAN_EVENT_METADATA_LEN;
120 metadata->vers = FANOTIFY_METADATA_VERSION;
121 metadata->mask = event->mask & FAN_ALL_OUTGOING_EVENTS;
122 metadata->pid = pid_vnr(event->tgid);
123 if (unlikely(event->mask & FAN_Q_OVERFLOW))
124 metadata->fd = FAN_NOFD;
125 else {
126 metadata->fd = create_fd(group, event);
127 if (metadata->fd < 0)
128 ret = metadata->fd;
129 }
130
131 return ret;
132}
133
134#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
135static struct fanotify_response_event *dequeue_re(struct fsnotify_group *group,
136 __s32 fd)
137{
138 struct fanotify_response_event *re, *return_re = NULL;
139
140 mutex_lock(&group->fanotify_data.access_mutex);
141 list_for_each_entry(re, &group->fanotify_data.access_list, list) {
142 if (re->fd != fd)
143 continue;
144
145 list_del_init(&re->list);
146 return_re = re;
147 break;
148 }
149 mutex_unlock(&group->fanotify_data.access_mutex);
150
151 pr_debug("%s: found return_re=%p\n", __func__, return_re);
152
153 return return_re;
154}
155
156static int process_access_response(struct fsnotify_group *group,
157 struct fanotify_response *response_struct)
158{
159 struct fanotify_response_event *re;
160 __s32 fd = response_struct->fd;
161 __u32 response = response_struct->response;
162
163 pr_debug("%s: group=%p fd=%d response=%d\n", __func__, group,
164 fd, response);
165
166
167
168
169
170 switch (response) {
171 case FAN_ALLOW:
172 case FAN_DENY:
173 break;
174 default:
175 return -EINVAL;
176 }
177
178 if (fd < 0)
179 return -EINVAL;
180
181 re = dequeue_re(group, fd);
182 if (!re)
183 return -ENOENT;
184
185 re->event->response = response;
186
187 wake_up(&group->fanotify_data.access_waitq);
188
189 kmem_cache_free(fanotify_response_event_cache, re);
190
191 return 0;
192}
193
194static int prepare_for_access_response(struct fsnotify_group *group,
195 struct fsnotify_event *event,
196 __s32 fd)
197{
198 struct fanotify_response_event *re;
199
200 if (!(event->mask & FAN_ALL_PERM_EVENTS))
201 return 0;
202
203 re = kmem_cache_alloc(fanotify_response_event_cache, GFP_KERNEL);
204 if (!re)
205 return -ENOMEM;
206
207 re->event = event;
208 re->fd = fd;
209
210 mutex_lock(&group->fanotify_data.access_mutex);
211
212 if (atomic_read(&group->fanotify_data.bypass_perm)) {
213 mutex_unlock(&group->fanotify_data.access_mutex);
214 kmem_cache_free(fanotify_response_event_cache, re);
215 event->response = FAN_ALLOW;
216 return 0;
217 }
218
219 list_add_tail(&re->list, &group->fanotify_data.access_list);
220 mutex_unlock(&group->fanotify_data.access_mutex);
221
222 return 0;
223}
224
225static void remove_access_response(struct fsnotify_group *group,
226 struct fsnotify_event *event,
227 __s32 fd)
228{
229 struct fanotify_response_event *re;
230
231 if (!(event->mask & FAN_ALL_PERM_EVENTS))
232 return;
233
234 re = dequeue_re(group, fd);
235 if (!re)
236 return;
237
238 BUG_ON(re->event != event);
239
240 kmem_cache_free(fanotify_response_event_cache, re);
241
242 return;
243}
244#else
245static int prepare_for_access_response(struct fsnotify_group *group,
246 struct fsnotify_event *event,
247 __s32 fd)
248{
249 return 0;
250}
251
252static void remove_access_response(struct fsnotify_group *group,
253 struct fsnotify_event *event,
254 __s32 fd)
255{
256 return;
257}
258#endif
259
260static ssize_t copy_event_to_user(struct fsnotify_group *group,
261 struct fsnotify_event *event,
262 char __user *buf)
263{
264 struct fanotify_event_metadata fanotify_event_metadata;
265 int fd, ret;
266
267 pr_debug("%s: group=%p event=%p\n", __func__, group, event);
268
269 ret = fill_event_metadata(group, &fanotify_event_metadata, event);
270 if (ret < 0)
271 goto out;
272
273 fd = fanotify_event_metadata.fd;
274 ret = prepare_for_access_response(group, event, fd);
275 if (ret)
276 goto out_close_fd;
277
278 ret = -EFAULT;
279 if (copy_to_user(buf, &fanotify_event_metadata,
280 fanotify_event_metadata.event_len))
281 goto out_kill_access_response;
282
283 return fanotify_event_metadata.event_len;
284
285out_kill_access_response:
286 remove_access_response(group, event, fd);
287out_close_fd:
288 if (fd != FAN_NOFD)
289 sys_close(fd);
290out:
291#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
292 if (event->mask & FAN_ALL_PERM_EVENTS) {
293 event->response = FAN_DENY;
294 wake_up(&group->fanotify_data.access_waitq);
295 }
296#endif
297 return ret;
298}
299
300
301static unsigned int fanotify_poll(struct file *file, poll_table *wait)
302{
303 struct fsnotify_group *group = file->private_data;
304 int ret = 0;
305
306 poll_wait(file, &group->notification_waitq, wait);
307 mutex_lock(&group->notification_mutex);
308 if (!fsnotify_notify_queue_is_empty(group))
309 ret = POLLIN | POLLRDNORM;
310 mutex_unlock(&group->notification_mutex);
311
312 return ret;
313}
314
315static ssize_t fanotify_read(struct file *file, char __user *buf,
316 size_t count, loff_t *pos)
317{
318 struct fsnotify_group *group;
319 struct fsnotify_event *kevent;
320 char __user *start;
321 int ret;
322 DEFINE_WAIT(wait);
323
324 start = buf;
325 group = file->private_data;
326
327 pr_debug("%s: group=%p\n", __func__, group);
328
329 while (1) {
330 prepare_to_wait(&group->notification_waitq, &wait, TASK_INTERRUPTIBLE);
331
332 mutex_lock(&group->notification_mutex);
333 kevent = get_one_event(group, count);
334 mutex_unlock(&group->notification_mutex);
335
336 if (kevent) {
337 ret = PTR_ERR(kevent);
338 if (IS_ERR(kevent))
339 break;
340 ret = copy_event_to_user(group, kevent, buf);
341 fsnotify_put_event(kevent);
342 if (ret < 0)
343 break;
344 buf += ret;
345 count -= ret;
346 continue;
347 }
348
349 ret = -EAGAIN;
350 if (file->f_flags & O_NONBLOCK)
351 break;
352 ret = -ERESTARTSYS;
353 if (signal_pending(current))
354 break;
355
356 if (start != buf)
357 break;
358
359 schedule();
360 }
361
362 finish_wait(&group->notification_waitq, &wait);
363 if (start != buf && ret != -EFAULT)
364 ret = buf - start;
365 return ret;
366}
367
368static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
369{
370#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
371 struct fanotify_response response = { .fd = -1, .response = -1 };
372 struct fsnotify_group *group;
373 int ret;
374
375 group = file->private_data;
376
377 if (count > sizeof(response))
378 count = sizeof(response);
379
380 pr_debug("%s: group=%p count=%zu\n", __func__, group, count);
381
382 if (copy_from_user(&response, buf, count))
383 return -EFAULT;
384
385 ret = process_access_response(group, &response);
386 if (ret < 0)
387 count = ret;
388
389 return count;
390#else
391 return -EINVAL;
392#endif
393}
394
395static int fanotify_release(struct inode *ignored, struct file *file)
396{
397 struct fsnotify_group *group = file->private_data;
398
399#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
400 struct fanotify_response_event *re, *lre;
401
402 mutex_lock(&group->fanotify_data.access_mutex);
403
404 atomic_inc(&group->fanotify_data.bypass_perm);
405
406 list_for_each_entry_safe(re, lre, &group->fanotify_data.access_list, list) {
407 pr_debug("%s: found group=%p re=%p event=%p\n", __func__, group,
408 re, re->event);
409
410 list_del_init(&re->list);
411 re->event->response = FAN_ALLOW;
412
413 kmem_cache_free(fanotify_response_event_cache, re);
414 }
415 mutex_unlock(&group->fanotify_data.access_mutex);
416
417 wake_up(&group->fanotify_data.access_waitq);
418#endif
419
420 fsnotify_put_group(group);
421
422 return 0;
423}
424
425static long fanotify_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
426{
427 struct fsnotify_group *group;
428 struct fsnotify_event_holder *holder;
429 void __user *p;
430 int ret = -ENOTTY;
431 size_t send_len = 0;
432
433 group = file->private_data;
434
435 p = (void __user *) arg;
436
437 switch (cmd) {
438 case FIONREAD:
439 mutex_lock(&group->notification_mutex);
440 list_for_each_entry(holder, &group->notification_list, event_list)
441 send_len += FAN_EVENT_METADATA_LEN;
442 mutex_unlock(&group->notification_mutex);
443 ret = put_user(send_len, (int __user *) p);
444 break;
445 }
446
447 return ret;
448}
449
450static const struct file_operations fanotify_fops = {
451 .poll = fanotify_poll,
452 .read = fanotify_read,
453 .write = fanotify_write,
454 .fasync = NULL,
455 .release = fanotify_release,
456 .unlocked_ioctl = fanotify_ioctl,
457 .compat_ioctl = fanotify_ioctl,
458 .llseek = noop_llseek,
459};
460
461static void fanotify_free_mark(struct fsnotify_mark *fsn_mark)
462{
463 kmem_cache_free(fanotify_mark_cache, fsn_mark);
464}
465
466static int fanotify_find_path(int dfd, const char __user *filename,
467 struct path *path, unsigned int flags)
468{
469 int ret;
470
471 pr_debug("%s: dfd=%d filename=%p flags=%x\n", __func__,
472 dfd, filename, flags);
473
474 if (filename == NULL) {
475 struct file *file;
476 int fput_needed;
477
478 ret = -EBADF;
479 file = fget_light(dfd, &fput_needed);
480 if (!file)
481 goto out;
482
483 ret = -ENOTDIR;
484 if ((flags & FAN_MARK_ONLYDIR) &&
485 !(S_ISDIR(file->f_path.dentry->d_inode->i_mode))) {
486 fput_light(file, fput_needed);
487 goto out;
488 }
489
490 *path = file->f_path;
491 path_get(path);
492 fput_light(file, fput_needed);
493 } else {
494 unsigned int lookup_flags = 0;
495
496 if (!(flags & FAN_MARK_DONT_FOLLOW))
497 lookup_flags |= LOOKUP_FOLLOW;
498 if (flags & FAN_MARK_ONLYDIR)
499 lookup_flags |= LOOKUP_DIRECTORY;
500
501 ret = user_path_at(dfd, filename, lookup_flags, path);
502 if (ret)
503 goto out;
504 }
505
506
507 ret = inode_permission(path->dentry->d_inode, MAY_READ);
508 if (ret)
509 path_put(path);
510out:
511 return ret;
512}
513
514static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark,
515 __u32 mask,
516 unsigned int flags)
517{
518 __u32 oldmask;
519
520 spin_lock(&fsn_mark->lock);
521 if (!(flags & FAN_MARK_IGNORED_MASK)) {
522 oldmask = fsn_mark->mask;
523 fsnotify_set_mark_mask_locked(fsn_mark, (oldmask & ~mask));
524 } else {
525 oldmask = fsn_mark->ignored_mask;
526 fsnotify_set_mark_ignored_mask_locked(fsn_mark, (oldmask & ~mask));
527 }
528 spin_unlock(&fsn_mark->lock);
529
530 if (!(oldmask & ~mask))
531 fsnotify_destroy_mark(fsn_mark);
532
533 return mask & oldmask;
534}
535
536static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group,
537 struct vfsmount *mnt, __u32 mask,
538 unsigned int flags)
539{
540 struct fsnotify_mark *fsn_mark = NULL;
541 __u32 removed;
542
543 fsn_mark = fsnotify_find_vfsmount_mark(group, mnt);
544 if (!fsn_mark)
545 return -ENOENT;
546
547 removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags);
548 fsnotify_put_mark(fsn_mark);
549 if (removed & mnt->mnt_fsnotify_mask)
550 fsnotify_recalc_vfsmount_mask(mnt);
551
552 return 0;
553}
554
555static int fanotify_remove_inode_mark(struct fsnotify_group *group,
556 struct inode *inode, __u32 mask,
557 unsigned int flags)
558{
559 struct fsnotify_mark *fsn_mark = NULL;
560 __u32 removed;
561
562 fsn_mark = fsnotify_find_inode_mark(group, inode);
563 if (!fsn_mark)
564 return -ENOENT;
565
566 removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags);
567
568 fsnotify_put_mark(fsn_mark);
569 if (removed & inode->i_fsnotify_mask)
570 fsnotify_recalc_inode_mask(inode);
571
572 return 0;
573}
574
575static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark,
576 __u32 mask,
577 unsigned int flags)
578{
579 __u32 oldmask = -1;
580
581 spin_lock(&fsn_mark->lock);
582 if (!(flags & FAN_MARK_IGNORED_MASK)) {
583 oldmask = fsn_mark->mask;
584 fsnotify_set_mark_mask_locked(fsn_mark, (oldmask | mask));
585 } else {
586 __u32 tmask = fsn_mark->ignored_mask | mask;
587 fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
588 if (flags & FAN_MARK_IGNORED_SURV_MODIFY)
589 fsn_mark->flags |= FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY;
590 }
591
592 if (!(flags & FAN_MARK_ONDIR)) {
593 __u32 tmask = fsn_mark->ignored_mask | FAN_ONDIR;
594 fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
595 }
596
597 spin_unlock(&fsn_mark->lock);
598
599 return mask & ~oldmask;
600}
601
602static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
603 struct vfsmount *mnt, __u32 mask,
604 unsigned int flags)
605{
606 struct fsnotify_mark *fsn_mark;
607 __u32 added;
608 int ret = 0;
609
610 fsn_mark = fsnotify_find_vfsmount_mark(group, mnt);
611 if (!fsn_mark) {
612 if (atomic_read(&group->num_marks) > group->fanotify_data.max_marks)
613 return -ENOSPC;
614
615 fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
616 if (!fsn_mark)
617 return -ENOMEM;
618
619 fsnotify_init_mark(fsn_mark, fanotify_free_mark);
620 ret = fsnotify_add_mark(fsn_mark, group, NULL, mnt, 0);
621 if (ret)
622 goto err;
623 }
624 added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
625
626 if (added & ~mnt->mnt_fsnotify_mask)
627 fsnotify_recalc_vfsmount_mask(mnt);
628err:
629 fsnotify_put_mark(fsn_mark);
630 return ret;
631}
632
633static int fanotify_add_inode_mark(struct fsnotify_group *group,
634 struct inode *inode, __u32 mask,
635 unsigned int flags)
636{
637 struct fsnotify_mark *fsn_mark;
638 __u32 added;
639 int ret = 0;
640
641 pr_debug("%s: group=%p inode=%p\n", __func__, group, inode);
642
643
644
645
646
647
648 if ((flags & FAN_MARK_IGNORED_MASK) &&
649 !(flags & FAN_MARK_IGNORED_SURV_MODIFY) &&
650 (atomic_read(&inode->i_writecount) > 0))
651 return 0;
652
653 fsn_mark = fsnotify_find_inode_mark(group, inode);
654 if (!fsn_mark) {
655 if (atomic_read(&group->num_marks) > group->fanotify_data.max_marks)
656 return -ENOSPC;
657
658 fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
659 if (!fsn_mark)
660 return -ENOMEM;
661
662 fsnotify_init_mark(fsn_mark, fanotify_free_mark);
663 ret = fsnotify_add_mark(fsn_mark, group, inode, NULL, 0);
664 if (ret)
665 goto err;
666 }
667 added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
668
669 if (added & ~inode->i_fsnotify_mask)
670 fsnotify_recalc_inode_mask(inode);
671err:
672 fsnotify_put_mark(fsn_mark);
673 return ret;
674}
675
676
677SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
678{
679 struct fsnotify_group *group;
680 int f_flags, fd;
681 struct user_struct *user;
682
683 pr_debug("%s: flags=%d event_f_flags=%d\n",
684 __func__, flags, event_f_flags);
685
686 if (!capable(CAP_SYS_ADMIN))
687 return -EPERM;
688
689 if (flags & ~FAN_ALL_INIT_FLAGS)
690 return -EINVAL;
691
692 user = get_current_user();
693 if (atomic_read(&user->fanotify_listeners) > FANOTIFY_DEFAULT_MAX_LISTENERS) {
694 free_uid(user);
695 return -EMFILE;
696 }
697
698 f_flags = O_RDWR | FMODE_NONOTIFY;
699 if (flags & FAN_CLOEXEC)
700 f_flags |= O_CLOEXEC;
701 if (flags & FAN_NONBLOCK)
702 f_flags |= O_NONBLOCK;
703
704
705 group = fsnotify_alloc_group(&fanotify_fsnotify_ops);
706 if (IS_ERR(group)) {
707 free_uid(user);
708 return PTR_ERR(group);
709 }
710
711 group->fanotify_data.user = user;
712 atomic_inc(&user->fanotify_listeners);
713
714 group->fanotify_data.f_flags = event_f_flags;
715#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
716 mutex_init(&group->fanotify_data.access_mutex);
717 init_waitqueue_head(&group->fanotify_data.access_waitq);
718 INIT_LIST_HEAD(&group->fanotify_data.access_list);
719 atomic_set(&group->fanotify_data.bypass_perm, 0);
720#endif
721 switch (flags & FAN_ALL_CLASS_BITS) {
722 case FAN_CLASS_NOTIF:
723 group->priority = FS_PRIO_0;
724 break;
725 case FAN_CLASS_CONTENT:
726 group->priority = FS_PRIO_1;
727 break;
728 case FAN_CLASS_PRE_CONTENT:
729 group->priority = FS_PRIO_2;
730 break;
731 default:
732 fd = -EINVAL;
733 goto out_put_group;
734 }
735
736 if (flags & FAN_UNLIMITED_QUEUE) {
737 fd = -EPERM;
738 if (!capable(CAP_SYS_ADMIN))
739 goto out_put_group;
740 group->max_events = UINT_MAX;
741 } else {
742 group->max_events = FANOTIFY_DEFAULT_MAX_EVENTS;
743 }
744
745 if (flags & FAN_UNLIMITED_MARKS) {
746 fd = -EPERM;
747 if (!capable(CAP_SYS_ADMIN))
748 goto out_put_group;
749 group->fanotify_data.max_marks = UINT_MAX;
750 } else {
751 group->fanotify_data.max_marks = FANOTIFY_DEFAULT_MAX_MARKS;
752 }
753
754 fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags);
755 if (fd < 0)
756 goto out_put_group;
757
758 return fd;
759
760out_put_group:
761 fsnotify_put_group(group);
762 return fd;
763}
764
765SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags,
766 __u64 mask, int dfd,
767 const char __user * pathname)
768{
769 struct inode *inode = NULL;
770 struct vfsmount *mnt = NULL;
771 struct fsnotify_group *group;
772 struct file *filp;
773 struct path path;
774 int ret, fput_needed;
775
776 pr_debug("%s: fanotify_fd=%d flags=%x dfd=%d pathname=%p mask=%llx\n",
777 __func__, fanotify_fd, flags, dfd, pathname, mask);
778
779
780 if (mask & ((__u64)0xffffffff << 32))
781 return -EINVAL;
782
783 if (flags & ~FAN_ALL_MARK_FLAGS)
784 return -EINVAL;
785 switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) {
786 case FAN_MARK_ADD:
787 case FAN_MARK_REMOVE:
788 if (!mask)
789 return -EINVAL;
790 case FAN_MARK_FLUSH:
791 break;
792 default:
793 return -EINVAL;
794 }
795
796 if (mask & FAN_ONDIR) {
797 flags |= FAN_MARK_ONDIR;
798 mask &= ~FAN_ONDIR;
799 }
800
801#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
802 if (mask & ~(FAN_ALL_EVENTS | FAN_ALL_PERM_EVENTS | FAN_EVENT_ON_CHILD))
803#else
804 if (mask & ~(FAN_ALL_EVENTS | FAN_EVENT_ON_CHILD))
805#endif
806 return -EINVAL;
807
808 filp = fget_light(fanotify_fd, &fput_needed);
809 if (unlikely(!filp))
810 return -EBADF;
811
812
813 ret = -EINVAL;
814 if (unlikely(filp->f_op != &fanotify_fops))
815 goto fput_and_out;
816 group = filp->private_data;
817
818
819
820
821
822 ret = -EINVAL;
823 if (mask & FAN_ALL_PERM_EVENTS &&
824 group->priority == FS_PRIO_0)
825 goto fput_and_out;
826
827 ret = fanotify_find_path(dfd, pathname, &path, flags);
828 if (ret)
829 goto fput_and_out;
830
831
832 if (!(flags & FAN_MARK_MOUNT))
833 inode = path.dentry->d_inode;
834 else
835 mnt = path.mnt;
836
837
838 switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) {
839 case FAN_MARK_ADD:
840 if (flags & FAN_MARK_MOUNT)
841 ret = fanotify_add_vfsmount_mark(group, mnt, mask, flags);
842 else
843 ret = fanotify_add_inode_mark(group, inode, mask, flags);
844 break;
845 case FAN_MARK_REMOVE:
846 if (flags & FAN_MARK_MOUNT)
847 ret = fanotify_remove_vfsmount_mark(group, mnt, mask, flags);
848 else
849 ret = fanotify_remove_inode_mark(group, inode, mask, flags);
850 break;
851 case FAN_MARK_FLUSH:
852 if (flags & FAN_MARK_MOUNT)
853 fsnotify_clear_vfsmount_marks_by_group(group);
854 else
855 fsnotify_clear_inode_marks_by_group(group);
856 break;
857 default:
858 ret = -EINVAL;
859 }
860
861 path_put(&path);
862fput_and_out:
863 fput_light(filp, fput_needed);
864 return ret;
865}
866
867#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
868asmlinkage long SyS_fanotify_mark(long fanotify_fd, long flags, __u64 mask,
869 long dfd, long pathname)
870{
871 return SYSC_fanotify_mark((int) fanotify_fd, (unsigned int) flags,
872 mask, (int) dfd,
873 (const char __user *) pathname);
874}
875SYSCALL_ALIAS(sys_fanotify_mark, SyS_fanotify_mark);
876#endif
877
878
879
880
881
882
883static int __init fanotify_user_setup(void)
884{
885 fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, SLAB_PANIC);
886 fanotify_response_event_cache = KMEM_CACHE(fanotify_response_event,
887 SLAB_PANIC);
888
889 return 0;
890}
891device_initcall(fanotify_user_setup);
892
