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#include <linux/compat.h>
17
18#include <asm/ioctls.h>
19
20#include "../../mount.h"
21#include "../fdinfo.h"
22#include "fanotify.h"
23
24#define FANOTIFY_DEFAULT_MAX_EVENTS 16384
25#define FANOTIFY_DEFAULT_MAX_MARKS 8192
26#define FANOTIFY_DEFAULT_MAX_LISTENERS 128
27
28
29
30
31
32
33
34
35
36#define FANOTIFY_INIT_ALL_EVENT_F_BITS ( \
37 O_ACCMODE | O_APPEND | O_NONBLOCK | \
38 __O_SYNC | O_DSYNC | O_CLOEXEC | \
39 O_LARGEFILE | O_NOATIME )
40
41extern const struct fsnotify_ops fanotify_fsnotify_ops;
42
43static struct kmem_cache *fanotify_mark_cache __read_mostly;
44struct kmem_cache *fanotify_event_cachep __read_mostly;
45struct kmem_cache *fanotify_perm_event_cachep __read_mostly;
46
47
48
49
50
51
52
53
54static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
55 size_t count)
56{
57 BUG_ON(!mutex_is_locked(&group->notification_mutex));
58
59 pr_debug("%s: group=%p count=%zd\n", __func__, group, count);
60
61 if (fsnotify_notify_queue_is_empty(group))
62 return NULL;
63
64 if (FAN_EVENT_METADATA_LEN > count)
65 return ERR_PTR(-EINVAL);
66
67
68
69 return fsnotify_remove_first_event(group);
70}
71
72static int create_fd(struct fsnotify_group *group,
73 struct fanotify_event_info *event,
74 struct file **file)
75{
76 int client_fd;
77 struct file *new_file;
78
79 pr_debug("%s: group=%p event=%p\n", __func__, group, event);
80
81 client_fd = get_unused_fd_flags(group->fanotify_data.f_flags);
82 if (client_fd < 0)
83 return client_fd;
84
85
86
87
88
89
90
91 if (event->path.dentry && event->path.mnt)
92 new_file = dentry_open(&event->path,
93 group->fanotify_data.f_flags | FMODE_NONOTIFY,
94 current_cred());
95 else
96 new_file = ERR_PTR(-EOVERFLOW);
97 if (IS_ERR(new_file)) {
98
99
100
101
102
103
104
105 put_unused_fd(client_fd);
106 client_fd = PTR_ERR(new_file);
107 } else {
108 *file = new_file;
109 }
110
111 return client_fd;
112}
113
114static int fill_event_metadata(struct fsnotify_group *group,
115 struct fanotify_event_metadata *metadata,
116 struct fsnotify_event *fsn_event,
117 struct file **file)
118{
119 int ret = 0;
120 struct fanotify_event_info *event;
121
122 pr_debug("%s: group=%p metadata=%p event=%p\n", __func__,
123 group, metadata, fsn_event);
124
125 *file = NULL;
126 event = container_of(fsn_event, struct fanotify_event_info, fse);
127 metadata->event_len = FAN_EVENT_METADATA_LEN;
128 metadata->metadata_len = FAN_EVENT_METADATA_LEN;
129 metadata->vers = FANOTIFY_METADATA_VERSION;
130 metadata->reserved = 0;
131 metadata->mask = fsn_event->mask & FAN_ALL_OUTGOING_EVENTS;
132 metadata->pid = pid_vnr(event->tgid);
133 if (unlikely(fsn_event->mask & FAN_Q_OVERFLOW))
134 metadata->fd = FAN_NOFD;
135 else {
136 metadata->fd = create_fd(group, event, file);
137 if (metadata->fd < 0)
138 ret = metadata->fd;
139 }
140
141 return ret;
142}
143
144#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
145static struct fanotify_perm_event_info *dequeue_event(
146 struct fsnotify_group *group, int fd)
147{
148 struct fanotify_perm_event_info *event, *return_e = NULL;
149
150 spin_lock(&group->fanotify_data.access_lock);
151 list_for_each_entry(event, &group->fanotify_data.access_list,
152 fae.fse.list) {
153 if (event->fd != fd)
154 continue;
155
156 list_del_init(&event->fae.fse.list);
157 return_e = event;
158 break;
159 }
160 spin_unlock(&group->fanotify_data.access_lock);
161
162 pr_debug("%s: found return_re=%p\n", __func__, return_e);
163
164 return return_e;
165}
166
167static int process_access_response(struct fsnotify_group *group,
168 struct fanotify_response *response_struct)
169{
170 struct fanotify_perm_event_info *event;
171 int fd = response_struct->fd;
172 int response = response_struct->response;
173
174 pr_debug("%s: group=%p fd=%d response=%d\n", __func__, group,
175 fd, response);
176
177
178
179
180
181 switch (response) {
182 case FAN_ALLOW:
183 case FAN_DENY:
184 break;
185 default:
186 return -EINVAL;
187 }
188
189 if (fd < 0)
190 return -EINVAL;
191
192 event = dequeue_event(group, fd);
193 if (!event)
194 return -ENOENT;
195
196 event->response = response;
197 wake_up(&group->fanotify_data.access_waitq);
198
199 return 0;
200}
201#endif
202
203static ssize_t copy_event_to_user(struct fsnotify_group *group,
204 struct fsnotify_event *event,
205 char __user *buf)
206{
207 struct fanotify_event_metadata fanotify_event_metadata;
208 struct file *f;
209 int fd, ret;
210
211 pr_debug("%s: group=%p event=%p\n", __func__, group, event);
212
213 ret = fill_event_metadata(group, &fanotify_event_metadata, event, &f);
214 if (ret < 0)
215 return ret;
216
217 fd = fanotify_event_metadata.fd;
218 ret = -EFAULT;
219 if (copy_to_user(buf, &fanotify_event_metadata,
220 fanotify_event_metadata.event_len))
221 goto out_close_fd;
222
223#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
224 if (event->mask & FAN_ALL_PERM_EVENTS)
225 FANOTIFY_PE(event)->fd = fd;
226#endif
227
228 if (fd != FAN_NOFD)
229 fd_install(fd, f);
230 return fanotify_event_metadata.event_len;
231
232out_close_fd:
233 if (fd != FAN_NOFD) {
234 put_unused_fd(fd);
235 fput(f);
236 }
237 return ret;
238}
239
240
241static unsigned int fanotify_poll(struct file *file, poll_table *wait)
242{
243 struct fsnotify_group *group = file->private_data;
244 int ret = 0;
245
246 poll_wait(file, &group->notification_waitq, wait);
247 mutex_lock(&group->notification_mutex);
248 if (!fsnotify_notify_queue_is_empty(group))
249 ret = POLLIN | POLLRDNORM;
250 mutex_unlock(&group->notification_mutex);
251
252 return ret;
253}
254
255static ssize_t fanotify_read(struct file *file, char __user *buf,
256 size_t count, loff_t *pos)
257{
258 struct fsnotify_group *group;
259 struct fsnotify_event *kevent;
260 char __user *start;
261 int ret;
262 DEFINE_WAIT_FUNC(wait, woken_wake_function);
263
264 start = buf;
265 group = file->private_data;
266
267 pr_debug("%s: group=%p\n", __func__, group);
268
269 add_wait_queue(&group->notification_waitq, &wait);
270 while (1) {
271 mutex_lock(&group->notification_mutex);
272 kevent = get_one_event(group, count);
273 mutex_unlock(&group->notification_mutex);
274
275 if (IS_ERR(kevent)) {
276 ret = PTR_ERR(kevent);
277 break;
278 }
279
280 if (!kevent) {
281 ret = -EAGAIN;
282 if (file->f_flags & O_NONBLOCK)
283 break;
284
285 ret = -ERESTARTSYS;
286 if (signal_pending(current))
287 break;
288
289 if (start != buf)
290 break;
291
292 wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
293 continue;
294 }
295
296 ret = copy_event_to_user(group, kevent, buf);
297
298
299
300
301 if (!(kevent->mask & FAN_ALL_PERM_EVENTS)) {
302 fsnotify_destroy_event(group, kevent);
303 if (ret < 0)
304 break;
305 } else {
306#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
307 if (ret < 0) {
308 FANOTIFY_PE(kevent)->response = FAN_DENY;
309 wake_up(&group->fanotify_data.access_waitq);
310 break;
311 }
312 spin_lock(&group->fanotify_data.access_lock);
313 list_add_tail(&kevent->list,
314 &group->fanotify_data.access_list);
315 spin_unlock(&group->fanotify_data.access_lock);
316#endif
317 }
318 buf += ret;
319 count -= ret;
320 }
321 remove_wait_queue(&group->notification_waitq, &wait);
322
323 if (start != buf && ret != -EFAULT)
324 ret = buf - start;
325 return ret;
326}
327
328static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
329{
330#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
331 struct fanotify_response response = { .fd = -1, .response = -1 };
332 struct fsnotify_group *group;
333 int ret;
334
335 group = file->private_data;
336
337 if (count > sizeof(response))
338 count = sizeof(response);
339
340 pr_debug("%s: group=%p count=%zu\n", __func__, group, count);
341
342 if (copy_from_user(&response, buf, count))
343 return -EFAULT;
344
345 ret = process_access_response(group, &response);
346 if (ret < 0)
347 count = ret;
348
349 return count;
350#else
351 return -EINVAL;
352#endif
353}
354
355static int fanotify_release(struct inode *ignored, struct file *file)
356{
357 struct fsnotify_group *group = file->private_data;
358
359#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
360 struct fanotify_perm_event_info *event, *next;
361
362
363
364
365
366
367 spin_lock(&group->fanotify_data.access_lock);
368
369 atomic_inc(&group->fanotify_data.bypass_perm);
370
371 list_for_each_entry_safe(event, next, &group->fanotify_data.access_list,
372 fae.fse.list) {
373 pr_debug("%s: found group=%p event=%p\n", __func__, group,
374 event);
375
376 list_del_init(&event->fae.fse.list);
377 event->response = FAN_ALLOW;
378 }
379 spin_unlock(&group->fanotify_data.access_lock);
380
381
382
383
384
385
386
387
388 wake_up(&group->fanotify_data.access_waitq);
389#endif
390
391
392 fsnotify_destroy_group(group);
393
394 return 0;
395}
396
397static long fanotify_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
398{
399 struct fsnotify_group *group;
400 struct fsnotify_event *fsn_event;
401 void __user *p;
402 int ret = -ENOTTY;
403 size_t send_len = 0;
404
405 group = file->private_data;
406
407 p = (void __user *) arg;
408
409 switch (cmd) {
410 case FIONREAD:
411 mutex_lock(&group->notification_mutex);
412 list_for_each_entry(fsn_event, &group->notification_list, list)
413 send_len += FAN_EVENT_METADATA_LEN;
414 mutex_unlock(&group->notification_mutex);
415 ret = put_user(send_len, (int __user *) p);
416 break;
417 }
418
419 return ret;
420}
421
422static const struct file_operations fanotify_fops = {
423 .show_fdinfo = fanotify_show_fdinfo,
424 .poll = fanotify_poll,
425 .read = fanotify_read,
426 .write = fanotify_write,
427 .fasync = NULL,
428 .release = fanotify_release,
429 .unlocked_ioctl = fanotify_ioctl,
430 .compat_ioctl = fanotify_ioctl,
431 .llseek = noop_llseek,
432};
433
434static void fanotify_free_mark(struct fsnotify_mark *fsn_mark)
435{
436 kmem_cache_free(fanotify_mark_cache, fsn_mark);
437}
438
439static int fanotify_find_path(int dfd, const char __user *filename,
440 struct path *path, unsigned int flags)
441{
442 int ret;
443
444 pr_debug("%s: dfd=%d filename=%p flags=%x\n", __func__,
445 dfd, filename, flags);
446
447 if (filename == NULL) {
448 struct fd f = fdget(dfd);
449
450 ret = -EBADF;
451 if (!f.file)
452 goto out;
453
454 ret = -ENOTDIR;
455 if ((flags & FAN_MARK_ONLYDIR) &&
456 !(S_ISDIR(file_inode(f.file)->i_mode))) {
457 fdput(f);
458 goto out;
459 }
460
461 *path = f.file->f_path;
462 path_get(path);
463 fdput(f);
464 } else {
465 unsigned int lookup_flags = 0;
466
467 if (!(flags & FAN_MARK_DONT_FOLLOW))
468 lookup_flags |= LOOKUP_FOLLOW;
469 if (flags & FAN_MARK_ONLYDIR)
470 lookup_flags |= LOOKUP_DIRECTORY;
471
472 ret = user_path_at(dfd, filename, lookup_flags, path);
473 if (ret)
474 goto out;
475 }
476
477
478 ret = inode_permission(path->dentry->d_inode, MAY_READ);
479 if (ret)
480 path_put(path);
481out:
482 return ret;
483}
484
485static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark,
486 __u32 mask,
487 unsigned int flags,
488 int *destroy)
489{
490 __u32 oldmask = 0;
491
492 spin_lock(&fsn_mark->lock);
493 if (!(flags & FAN_MARK_IGNORED_MASK)) {
494 __u32 tmask = fsn_mark->mask & ~mask;
495
496 if (flags & FAN_MARK_ONDIR)
497 tmask &= ~FAN_ONDIR;
498
499 oldmask = fsn_mark->mask;
500 fsnotify_set_mark_mask_locked(fsn_mark, tmask);
501 } else {
502 __u32 tmask = fsn_mark->ignored_mask & ~mask;
503 if (flags & FAN_MARK_ONDIR)
504 tmask &= ~FAN_ONDIR;
505
506 fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
507 }
508 *destroy = !(fsn_mark->mask | fsn_mark->ignored_mask);
509 spin_unlock(&fsn_mark->lock);
510
511 return mask & oldmask;
512}
513
514static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group,
515 struct vfsmount *mnt, __u32 mask,
516 unsigned int flags)
517{
518 struct fsnotify_mark *fsn_mark = NULL;
519 __u32 removed;
520 int destroy_mark;
521
522 mutex_lock(&group->mark_mutex);
523 fsn_mark = fsnotify_find_vfsmount_mark(group, mnt);
524 if (!fsn_mark) {
525 mutex_unlock(&group->mark_mutex);
526 return -ENOENT;
527 }
528
529 removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags,
530 &destroy_mark);
531 if (destroy_mark)
532 fsnotify_detach_mark(fsn_mark);
533 mutex_unlock(&group->mark_mutex);
534 if (destroy_mark)
535 fsnotify_free_mark(fsn_mark);
536
537 fsnotify_put_mark(fsn_mark);
538 if (removed & real_mount(mnt)->mnt_fsnotify_mask)
539 fsnotify_recalc_vfsmount_mask(mnt);
540
541 return 0;
542}
543
544static int fanotify_remove_inode_mark(struct fsnotify_group *group,
545 struct inode *inode, __u32 mask,
546 unsigned int flags)
547{
548 struct fsnotify_mark *fsn_mark = NULL;
549 __u32 removed;
550 int destroy_mark;
551
552 mutex_lock(&group->mark_mutex);
553 fsn_mark = fsnotify_find_inode_mark(group, inode);
554 if (!fsn_mark) {
555 mutex_unlock(&group->mark_mutex);
556 return -ENOENT;
557 }
558
559 removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags,
560 &destroy_mark);
561 if (destroy_mark)
562 fsnotify_detach_mark(fsn_mark);
563 mutex_unlock(&group->mark_mutex);
564 if (destroy_mark)
565 fsnotify_free_mark(fsn_mark);
566
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 __u32 tmask = fsn_mark->mask | mask;
584
585 if (flags & FAN_MARK_ONDIR)
586 tmask |= FAN_ONDIR;
587
588 oldmask = fsn_mark->mask;
589 fsnotify_set_mark_mask_locked(fsn_mark, tmask);
590 } else {
591 __u32 tmask = fsn_mark->ignored_mask | mask;
592 if (flags & FAN_MARK_ONDIR)
593 tmask |= FAN_ONDIR;
594
595 fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask);
596 if (flags & FAN_MARK_IGNORED_SURV_MODIFY)
597 fsn_mark->flags |= FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY;
598 }
599 spin_unlock(&fsn_mark->lock);
600
601 return mask & ~oldmask;
602}
603
604static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
605 struct inode *inode,
606 struct vfsmount *mnt)
607{
608 struct fsnotify_mark *mark;
609 int ret;
610
611 if (atomic_read(&group->num_marks) > group->fanotify_data.max_marks)
612 return ERR_PTR(-ENOSPC);
613
614 mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
615 if (!mark)
616 return ERR_PTR(-ENOMEM);
617
618 fsnotify_init_mark(mark, fanotify_free_mark);
619 ret = fsnotify_add_mark_locked(mark, group, inode, mnt, 0);
620 if (ret) {
621 fsnotify_put_mark(mark);
622 return ERR_PTR(ret);
623 }
624
625 return mark;
626}
627
628
629static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
630 struct vfsmount *mnt, __u32 mask,
631 unsigned int flags)
632{
633 struct fsnotify_mark *fsn_mark;
634 __u32 added;
635
636 mutex_lock(&group->mark_mutex);
637 fsn_mark = fsnotify_find_vfsmount_mark(group, mnt);
638 if (!fsn_mark) {
639 fsn_mark = fanotify_add_new_mark(group, NULL, mnt);
640 if (IS_ERR(fsn_mark)) {
641 mutex_unlock(&group->mark_mutex);
642 return PTR_ERR(fsn_mark);
643 }
644 }
645 added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
646 mutex_unlock(&group->mark_mutex);
647
648 if (added & ~real_mount(mnt)->mnt_fsnotify_mask)
649 fsnotify_recalc_vfsmount_mask(mnt);
650
651 fsnotify_put_mark(fsn_mark);
652 return 0;
653}
654
655static int fanotify_add_inode_mark(struct fsnotify_group *group,
656 struct inode *inode, __u32 mask,
657 unsigned int flags)
658{
659 struct fsnotify_mark *fsn_mark;
660 __u32 added;
661
662 pr_debug("%s: group=%p inode=%p\n", __func__, group, inode);
663
664
665
666
667
668
669 if ((flags & FAN_MARK_IGNORED_MASK) &&
670 !(flags & FAN_MARK_IGNORED_SURV_MODIFY) &&
671 (atomic_read(&inode->i_writecount) > 0))
672 return 0;
673
674 mutex_lock(&group->mark_mutex);
675 fsn_mark = fsnotify_find_inode_mark(group, inode);
676 if (!fsn_mark) {
677 fsn_mark = fanotify_add_new_mark(group, inode, NULL);
678 if (IS_ERR(fsn_mark)) {
679 mutex_unlock(&group->mark_mutex);
680 return PTR_ERR(fsn_mark);
681 }
682 }
683 added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
684 mutex_unlock(&group->mark_mutex);
685
686 if (added & ~inode->i_fsnotify_mask)
687 fsnotify_recalc_inode_mask(inode);
688
689 fsnotify_put_mark(fsn_mark);
690 return 0;
691}
692
693
694SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
695{
696 struct fsnotify_group *group;
697 int f_flags, fd;
698 struct user_struct *user;
699 struct fanotify_event_info *oevent;
700
701 pr_debug("%s: flags=%d event_f_flags=%d\n",
702 __func__, flags, event_f_flags);
703
704 if (!capable(CAP_SYS_ADMIN))
705 return -EPERM;
706
707 if (flags & ~FAN_ALL_INIT_FLAGS)
708 return -EINVAL;
709
710 if (event_f_flags & ~FANOTIFY_INIT_ALL_EVENT_F_BITS)
711 return -EINVAL;
712
713 switch (event_f_flags & O_ACCMODE) {
714 case O_RDONLY:
715 case O_RDWR:
716 case O_WRONLY:
717 break;
718 default:
719 return -EINVAL;
720 }
721
722 user = get_current_user();
723 if (atomic_read(&user->fanotify_listeners) > FANOTIFY_DEFAULT_MAX_LISTENERS) {
724 free_uid(user);
725 return -EMFILE;
726 }
727
728 f_flags = O_RDWR | FMODE_NONOTIFY;
729 if (flags & FAN_CLOEXEC)
730 f_flags |= O_CLOEXEC;
731 if (flags & FAN_NONBLOCK)
732 f_flags |= O_NONBLOCK;
733
734
735 group = fsnotify_alloc_group(&fanotify_fsnotify_ops);
736 if (IS_ERR(group)) {
737 free_uid(user);
738 return PTR_ERR(group);
739 }
740
741 group->fanotify_data.user = user;
742 atomic_inc(&user->fanotify_listeners);
743
744 oevent = fanotify_alloc_event(NULL, FS_Q_OVERFLOW, NULL);
745 if (unlikely(!oevent)) {
746 fd = -ENOMEM;
747 goto out_destroy_group;
748 }
749 group->overflow_event = &oevent->fse;
750
751 if (force_o_largefile())
752 event_f_flags |= O_LARGEFILE;
753 group->fanotify_data.f_flags = event_f_flags;
754#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
755 spin_lock_init(&group->fanotify_data.access_lock);
756 init_waitqueue_head(&group->fanotify_data.access_waitq);
757 INIT_LIST_HEAD(&group->fanotify_data.access_list);
758 atomic_set(&group->fanotify_data.bypass_perm, 0);
759#endif
760 switch (flags & FAN_ALL_CLASS_BITS) {
761 case FAN_CLASS_NOTIF:
762 group->priority = FS_PRIO_0;
763 break;
764 case FAN_CLASS_CONTENT:
765 group->priority = FS_PRIO_1;
766 break;
767 case FAN_CLASS_PRE_CONTENT:
768 group->priority = FS_PRIO_2;
769 break;
770 default:
771 fd = -EINVAL;
772 goto out_destroy_group;
773 }
774
775 if (flags & FAN_UNLIMITED_QUEUE) {
776 fd = -EPERM;
777 if (!capable(CAP_SYS_ADMIN))
778 goto out_destroy_group;
779 group->max_events = UINT_MAX;
780 } else {
781 group->max_events = FANOTIFY_DEFAULT_MAX_EVENTS;
782 }
783
784 if (flags & FAN_UNLIMITED_MARKS) {
785 fd = -EPERM;
786 if (!capable(CAP_SYS_ADMIN))
787 goto out_destroy_group;
788 group->fanotify_data.max_marks = UINT_MAX;
789 } else {
790 group->fanotify_data.max_marks = FANOTIFY_DEFAULT_MAX_MARKS;
791 }
792
793 fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags);
794 if (fd < 0)
795 goto out_destroy_group;
796
797 return fd;
798
799out_destroy_group:
800 fsnotify_destroy_group(group);
801 return fd;
802}
803
804SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags,
805 __u64, mask, int, dfd,
806 const char __user *, pathname)
807{
808 struct inode *inode = NULL;
809 struct vfsmount *mnt = NULL;
810 struct fsnotify_group *group;
811 struct fd f;
812 struct path path;
813 int ret;
814
815 pr_debug("%s: fanotify_fd=%d flags=%x dfd=%d pathname=%p mask=%llx\n",
816 __func__, fanotify_fd, flags, dfd, pathname, mask);
817
818
819 if (mask & ((__u64)0xffffffff << 32))
820 return -EINVAL;
821
822 if (flags & ~FAN_ALL_MARK_FLAGS)
823 return -EINVAL;
824 switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) {
825 case FAN_MARK_ADD:
826 case FAN_MARK_REMOVE:
827 if (!mask)
828 return -EINVAL;
829 break;
830 case FAN_MARK_FLUSH:
831 if (flags & ~(FAN_MARK_MOUNT | FAN_MARK_FLUSH))
832 return -EINVAL;
833 break;
834 default:
835 return -EINVAL;
836 }
837
838 if (mask & FAN_ONDIR) {
839 flags |= FAN_MARK_ONDIR;
840 mask &= ~FAN_ONDIR;
841 }
842
843#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
844 if (mask & ~(FAN_ALL_EVENTS | FAN_ALL_PERM_EVENTS | FAN_EVENT_ON_CHILD))
845#else
846 if (mask & ~(FAN_ALL_EVENTS | FAN_EVENT_ON_CHILD))
847#endif
848 return -EINVAL;
849
850 f = fdget(fanotify_fd);
851 if (unlikely(!f.file))
852 return -EBADF;
853
854
855 ret = -EINVAL;
856 if (unlikely(f.file->f_op != &fanotify_fops))
857 goto fput_and_out;
858 group = f.file->private_data;
859
860
861
862
863
864 ret = -EINVAL;
865 if (mask & FAN_ALL_PERM_EVENTS &&
866 group->priority == FS_PRIO_0)
867 goto fput_and_out;
868
869 if (flags & FAN_MARK_FLUSH) {
870 ret = 0;
871 if (flags & FAN_MARK_MOUNT)
872 fsnotify_clear_vfsmount_marks_by_group(group);
873 else
874 fsnotify_clear_inode_marks_by_group(group);
875 goto fput_and_out;
876 }
877
878 ret = fanotify_find_path(dfd, pathname, &path, flags);
879 if (ret)
880 goto fput_and_out;
881
882
883 if (!(flags & FAN_MARK_MOUNT))
884 inode = path.dentry->d_inode;
885 else
886 mnt = path.mnt;
887
888
889 switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE)) {
890 case FAN_MARK_ADD:
891 if (flags & FAN_MARK_MOUNT)
892 ret = fanotify_add_vfsmount_mark(group, mnt, mask, flags);
893 else
894 ret = fanotify_add_inode_mark(group, inode, mask, flags);
895 break;
896 case FAN_MARK_REMOVE:
897 if (flags & FAN_MARK_MOUNT)
898 ret = fanotify_remove_vfsmount_mark(group, mnt, mask, flags);
899 else
900 ret = fanotify_remove_inode_mark(group, inode, mask, flags);
901 break;
902 default:
903 ret = -EINVAL;
904 }
905
906 path_put(&path);
907fput_and_out:
908 fdput(f);
909 return ret;
910}
911
912#ifdef CONFIG_COMPAT
913COMPAT_SYSCALL_DEFINE6(fanotify_mark,
914 int, fanotify_fd, unsigned int, flags,
915 __u32, mask0, __u32, mask1, int, dfd,
916 const char __user *, pathname)
917{
918 return sys_fanotify_mark(fanotify_fd, flags,
919#ifdef __BIG_ENDIAN
920 ((__u64)mask0 << 32) | mask1,
921#else
922 ((__u64)mask1 << 32) | mask0,
923#endif
924 dfd, pathname);
925}
926#endif
927
928
929
930
931
932
933static int __init fanotify_user_setup(void)
934{
935 fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, SLAB_PANIC);
936 fanotify_event_cachep = KMEM_CACHE(fanotify_event_info, SLAB_PANIC);
937#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
938 fanotify_perm_event_cachep = KMEM_CACHE(fanotify_perm_event_info,
939 SLAB_PANIC);
940#endif
941
942 return 0;
943}
944device_initcall(fanotify_user_setup);
945
