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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
33d3dfff | 2 | #include <linux/fanotify.h> |
11637e4b | 3 | #include <linux/fcntl.h> |
2a3edf86 | 4 | #include <linux/file.h> |
11637e4b | 5 | #include <linux/fs.h> |
52c923dd | 6 | #include <linux/anon_inodes.h> |
11637e4b | 7 | #include <linux/fsnotify_backend.h> |
2a3edf86 | 8 | #include <linux/init.h> |
a1014f10 | 9 | #include <linux/mount.h> |
2a3edf86 | 10 | #include <linux/namei.h> |
a1014f10 | 11 | #include <linux/poll.h> |
11637e4b EP |
12 | #include <linux/security.h> |
13 | #include <linux/syscalls.h> | |
e4e047a2 | 14 | #include <linux/slab.h> |
2a3edf86 | 15 | #include <linux/types.h> |
a1014f10 | 16 | #include <linux/uaccess.h> |
91c2e0bc | 17 | #include <linux/compat.h> |
174cd4b1 | 18 | #include <linux/sched/signal.h> |
d46eb14b | 19 | #include <linux/memcontrol.h> |
a8b13aa2 AG |
20 | #include <linux/statfs.h> |
21 | #include <linux/exportfs.h> | |
a1014f10 EP |
22 | |
23 | #include <asm/ioctls.h> | |
11637e4b | 24 | |
c63181e6 | 25 | #include "../../mount.h" |
be77196b | 26 | #include "../fdinfo.h" |
7053aee2 | 27 | #include "fanotify.h" |
c63181e6 | 28 | |
2529a0df | 29 | #define FANOTIFY_DEFAULT_MAX_EVENTS 16384 |
e7099d8a | 30 | #define FANOTIFY_DEFAULT_MAX_MARKS 8192 |
4afeff85 | 31 | #define FANOTIFY_DEFAULT_MAX_LISTENERS 128 |
2529a0df | 32 | |
48149e9d HS |
33 | /* |
34 | * All flags that may be specified in parameter event_f_flags of fanotify_init. | |
35 | * | |
36 | * Internal and external open flags are stored together in field f_flags of | |
37 | * struct file. Only external open flags shall be allowed in event_f_flags. | |
38 | * Internal flags like FMODE_NONOTIFY, FMODE_EXEC, FMODE_NOCMTIME shall be | |
39 | * excluded. | |
40 | */ | |
41 | #define FANOTIFY_INIT_ALL_EVENT_F_BITS ( \ | |
42 | O_ACCMODE | O_APPEND | O_NONBLOCK | \ | |
43 | __O_SYNC | O_DSYNC | O_CLOEXEC | \ | |
44 | O_LARGEFILE | O_NOATIME ) | |
45 | ||
33d3dfff | 46 | extern const struct fsnotify_ops fanotify_fsnotify_ops; |
11637e4b | 47 | |
054c636e | 48 | struct kmem_cache *fanotify_mark_cache __read_mostly; |
7053aee2 | 49 | struct kmem_cache *fanotify_event_cachep __read_mostly; |
f083441b | 50 | struct kmem_cache *fanotify_perm_event_cachep __read_mostly; |
2a3edf86 | 51 | |
5e469c83 AG |
52 | #define FANOTIFY_EVENT_ALIGN 4 |
53 | ||
54 | static int fanotify_event_info_len(struct fanotify_event *event) | |
55 | { | |
56 | if (!fanotify_event_has_fid(event)) | |
57 | return 0; | |
58 | ||
59 | return roundup(sizeof(struct fanotify_event_info_fid) + | |
60 | sizeof(struct file_handle) + event->fh_len, | |
61 | FANOTIFY_EVENT_ALIGN); | |
62 | } | |
63 | ||
a1014f10 EP |
64 | /* |
65 | * Get an fsnotify notification event if one exists and is small | |
66 | * enough to fit in "count". Return an error pointer if the count | |
67 | * is not large enough. | |
a1014f10 EP |
68 | */ |
69 | static struct fsnotify_event *get_one_event(struct fsnotify_group *group, | |
70 | size_t count) | |
71 | { | |
5e469c83 | 72 | size_t event_size = FAN_EVENT_METADATA_LEN; |
8c554466 | 73 | struct fsnotify_event *fsn_event = NULL; |
a1014f10 EP |
74 | |
75 | pr_debug("%s: group=%p count=%zd\n", __func__, group, count); | |
76 | ||
8c554466 | 77 | spin_lock(&group->notification_lock); |
a1014f10 | 78 | if (fsnotify_notify_queue_is_empty(group)) |
8c554466 | 79 | goto out; |
a1014f10 | 80 | |
5e469c83 | 81 | if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { |
8c554466 JK |
82 | event_size += fanotify_event_info_len( |
83 | FANOTIFY_E(fsnotify_peek_first_event(group))); | |
5e469c83 AG |
84 | } |
85 | ||
8c554466 JK |
86 | if (event_size > count) { |
87 | fsn_event = ERR_PTR(-EINVAL); | |
88 | goto out; | |
89 | } | |
90 | fsn_event = fsnotify_remove_first_event(group); | |
91 | out: | |
92 | spin_unlock(&group->notification_lock); | |
93 | return fsn_event; | |
a1014f10 EP |
94 | } |
95 | ||
352e3b24 | 96 | static int create_fd(struct fsnotify_group *group, |
33913997 | 97 | struct fanotify_event *event, |
7053aee2 | 98 | struct file **file) |
a1014f10 EP |
99 | { |
100 | int client_fd; | |
a1014f10 EP |
101 | struct file *new_file; |
102 | ||
22aa425d | 103 | pr_debug("%s: group=%p event=%p\n", __func__, group, event); |
a1014f10 | 104 | |
0b37e097 | 105 | client_fd = get_unused_fd_flags(group->fanotify_data.f_flags); |
a1014f10 EP |
106 | if (client_fd < 0) |
107 | return client_fd; | |
108 | ||
a1014f10 EP |
109 | /* |
110 | * we need a new file handle for the userspace program so it can read even if it was | |
111 | * originally opened O_WRONLY. | |
112 | */ | |
a1014f10 EP |
113 | /* it's possible this event was an overflow event. in that case dentry and mnt |
114 | * are NULL; That's fine, just don't call dentry open */ | |
765927b2 AV |
115 | if (event->path.dentry && event->path.mnt) |
116 | new_file = dentry_open(&event->path, | |
80af2588 | 117 | group->fanotify_data.f_flags | FMODE_NONOTIFY, |
a1014f10 EP |
118 | current_cred()); |
119 | else | |
120 | new_file = ERR_PTR(-EOVERFLOW); | |
121 | if (IS_ERR(new_file)) { | |
122 | /* | |
123 | * we still send an event even if we can't open the file. this | |
124 | * can happen when say tasks are gone and we try to open their | |
125 | * /proc files or we try to open a WRONLY file like in sysfs | |
126 | * we just send the errno to userspace since there isn't much | |
127 | * else we can do. | |
128 | */ | |
129 | put_unused_fd(client_fd); | |
130 | client_fd = PTR_ERR(new_file); | |
131 | } else { | |
352e3b24 | 132 | *file = new_file; |
a1014f10 EP |
133 | } |
134 | ||
22aa425d | 135 | return client_fd; |
a1014f10 EP |
136 | } |
137 | ||
b2d87909 EP |
138 | static int process_access_response(struct fsnotify_group *group, |
139 | struct fanotify_response *response_struct) | |
140 | { | |
33913997 | 141 | struct fanotify_perm_event *event; |
f083441b JK |
142 | int fd = response_struct->fd; |
143 | int response = response_struct->response; | |
b2d87909 EP |
144 | |
145 | pr_debug("%s: group=%p fd=%d response=%d\n", __func__, group, | |
146 | fd, response); | |
147 | /* | |
148 | * make sure the response is valid, if invalid we do nothing and either | |
25985edc | 149 | * userspace can send a valid response or we will clean it up after the |
b2d87909 EP |
150 | * timeout |
151 | */ | |
de8cd83e | 152 | switch (response & ~FAN_AUDIT) { |
b2d87909 EP |
153 | case FAN_ALLOW: |
154 | case FAN_DENY: | |
155 | break; | |
156 | default: | |
157 | return -EINVAL; | |
158 | } | |
159 | ||
160 | if (fd < 0) | |
161 | return -EINVAL; | |
162 | ||
96a71f21 | 163 | if ((response & FAN_AUDIT) && !FAN_GROUP_FLAG(group, FAN_ENABLE_AUDIT)) |
de8cd83e SG |
164 | return -EINVAL; |
165 | ||
af6a5113 JK |
166 | spin_lock(&group->notification_lock); |
167 | list_for_each_entry(event, &group->fanotify_data.access_list, | |
168 | fae.fse.list) { | |
169 | if (event->fd != fd) | |
170 | continue; | |
b2d87909 | 171 | |
af6a5113 JK |
172 | list_del_init(&event->fae.fse.list); |
173 | event->response = response; | |
174 | spin_unlock(&group->notification_lock); | |
175 | wake_up(&group->fanotify_data.access_waitq); | |
176 | return 0; | |
177 | } | |
178 | spin_unlock(&group->notification_lock); | |
b2d87909 | 179 | |
af6a5113 | 180 | return -ENOENT; |
b2d87909 | 181 | } |
b2d87909 | 182 | |
5e469c83 AG |
183 | static int copy_fid_to_user(struct fanotify_event *event, char __user *buf) |
184 | { | |
185 | struct fanotify_event_info_fid info = { }; | |
186 | struct file_handle handle = { }; | |
187 | size_t fh_len = event->fh_len; | |
188 | size_t len = fanotify_event_info_len(event); | |
189 | ||
190 | if (!len) | |
191 | return 0; | |
192 | ||
193 | if (WARN_ON_ONCE(len < sizeof(info) + sizeof(handle) + fh_len)) | |
194 | return -EFAULT; | |
195 | ||
196 | /* Copy event info fid header followed by vaiable sized file handle */ | |
197 | info.hdr.info_type = FAN_EVENT_INFO_TYPE_FID; | |
198 | info.hdr.len = len; | |
199 | info.fsid = event->fid.fsid; | |
200 | if (copy_to_user(buf, &info, sizeof(info))) | |
201 | return -EFAULT; | |
202 | ||
203 | buf += sizeof(info); | |
204 | len -= sizeof(info); | |
205 | handle.handle_type = event->fh_type; | |
206 | handle.handle_bytes = fh_len; | |
207 | if (copy_to_user(buf, &handle, sizeof(handle))) | |
208 | return -EFAULT; | |
209 | ||
210 | buf += sizeof(handle); | |
211 | len -= sizeof(handle); | |
212 | if (copy_to_user(buf, fanotify_event_fh(event), fh_len)) | |
213 | return -EFAULT; | |
214 | ||
215 | /* Pad with 0's */ | |
216 | buf += fh_len; | |
217 | len -= fh_len; | |
218 | WARN_ON_ONCE(len < 0 || len >= FANOTIFY_EVENT_ALIGN); | |
219 | if (len > 0 && clear_user(buf, len)) | |
220 | return -EFAULT; | |
221 | ||
222 | return 0; | |
223 | } | |
224 | ||
a1014f10 | 225 | static ssize_t copy_event_to_user(struct fsnotify_group *group, |
bb2f7b45 | 226 | struct fsnotify_event *fsn_event, |
5b03a472 | 227 | char __user *buf, size_t count) |
a1014f10 | 228 | { |
bb2f7b45 AG |
229 | struct fanotify_event_metadata metadata; |
230 | struct fanotify_event *event; | |
231 | struct file *f = NULL; | |
e9e0c890 | 232 | int ret, fd = FAN_NOFD; |
a1014f10 | 233 | |
bb2f7b45 | 234 | pr_debug("%s: group=%p event=%p\n", __func__, group, fsn_event); |
a1014f10 | 235 | |
bb2f7b45 AG |
236 | event = container_of(fsn_event, struct fanotify_event, fse); |
237 | metadata.event_len = FAN_EVENT_METADATA_LEN; | |
238 | metadata.metadata_len = FAN_EVENT_METADATA_LEN; | |
239 | metadata.vers = FANOTIFY_METADATA_VERSION; | |
240 | metadata.reserved = 0; | |
241 | metadata.mask = event->mask & FANOTIFY_OUTGOING_EVENTS; | |
242 | metadata.pid = pid_vnr(event->pid); | |
243 | ||
e9e0c890 | 244 | if (fanotify_event_has_path(event)) { |
bb2f7b45 AG |
245 | fd = create_fd(group, event, &f); |
246 | if (fd < 0) | |
247 | return fd; | |
5e469c83 AG |
248 | } else if (fanotify_event_has_fid(event)) { |
249 | metadata.event_len += fanotify_event_info_len(event); | |
bb2f7b45 AG |
250 | } |
251 | metadata.fd = fd; | |
b2d87909 | 252 | |
b2d87909 | 253 | ret = -EFAULT; |
5b03a472 KC |
254 | /* |
255 | * Sanity check copy size in case get_one_event() and | |
256 | * fill_event_metadata() event_len sizes ever get out of sync. | |
257 | */ | |
bb2f7b45 | 258 | if (WARN_ON_ONCE(metadata.event_len > count)) |
5b03a472 | 259 | goto out_close_fd; |
bb2f7b45 | 260 | |
5e469c83 | 261 | if (copy_to_user(buf, &metadata, FAN_EVENT_METADATA_LEN)) |
352e3b24 AV |
262 | goto out_close_fd; |
263 | ||
bb2f7b45 AG |
264 | if (fanotify_is_perm_event(event->mask)) |
265 | FANOTIFY_PE(fsn_event)->fd = fd; | |
a1014f10 | 266 | |
5e469c83 | 267 | if (fanotify_event_has_path(event)) { |
3587b1b0 | 268 | fd_install(fd, f); |
5e469c83 AG |
269 | } else if (fanotify_event_has_fid(event)) { |
270 | ret = copy_fid_to_user(event, buf + FAN_EVENT_METADATA_LEN); | |
271 | if (ret < 0) | |
272 | return ret; | |
273 | } | |
274 | ||
bb2f7b45 | 275 | return metadata.event_len; |
b2d87909 | 276 | |
b2d87909 | 277 | out_close_fd: |
352e3b24 AV |
278 | if (fd != FAN_NOFD) { |
279 | put_unused_fd(fd); | |
280 | fput(f); | |
281 | } | |
b2d87909 | 282 | return ret; |
a1014f10 EP |
283 | } |
284 | ||
285 | /* intofiy userspace file descriptor functions */ | |
076ccb76 | 286 | static __poll_t fanotify_poll(struct file *file, poll_table *wait) |
a1014f10 EP |
287 | { |
288 | struct fsnotify_group *group = file->private_data; | |
076ccb76 | 289 | __poll_t ret = 0; |
a1014f10 EP |
290 | |
291 | poll_wait(file, &group->notification_waitq, wait); | |
c21dbe20 | 292 | spin_lock(&group->notification_lock); |
a1014f10 | 293 | if (!fsnotify_notify_queue_is_empty(group)) |
a9a08845 | 294 | ret = EPOLLIN | EPOLLRDNORM; |
c21dbe20 | 295 | spin_unlock(&group->notification_lock); |
a1014f10 EP |
296 | |
297 | return ret; | |
298 | } | |
299 | ||
300 | static ssize_t fanotify_read(struct file *file, char __user *buf, | |
301 | size_t count, loff_t *pos) | |
302 | { | |
303 | struct fsnotify_group *group; | |
304 | struct fsnotify_event *kevent; | |
305 | char __user *start; | |
306 | int ret; | |
536ebe9c | 307 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
a1014f10 EP |
308 | |
309 | start = buf; | |
310 | group = file->private_data; | |
311 | ||
312 | pr_debug("%s: group=%p\n", __func__, group); | |
313 | ||
536ebe9c | 314 | add_wait_queue(&group->notification_waitq, &wait); |
a1014f10 | 315 | while (1) { |
a1014f10 | 316 | kevent = get_one_event(group, count); |
d8aaab4f | 317 | if (IS_ERR(kevent)) { |
a1014f10 | 318 | ret = PTR_ERR(kevent); |
d8aaab4f JK |
319 | break; |
320 | } | |
321 | ||
322 | if (!kevent) { | |
323 | ret = -EAGAIN; | |
324 | if (file->f_flags & O_NONBLOCK) | |
a1014f10 | 325 | break; |
d8aaab4f JK |
326 | |
327 | ret = -ERESTARTSYS; | |
328 | if (signal_pending(current)) | |
329 | break; | |
330 | ||
331 | if (start != buf) | |
a1014f10 | 332 | break; |
536ebe9c PZ |
333 | |
334 | wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
a1014f10 EP |
335 | continue; |
336 | } | |
337 | ||
5b03a472 | 338 | ret = copy_event_to_user(group, kevent, buf, count); |
4ff33aaf AG |
339 | if (unlikely(ret == -EOPENSTALE)) { |
340 | /* | |
341 | * We cannot report events with stale fd so drop it. | |
342 | * Setting ret to 0 will continue the event loop and | |
343 | * do the right thing if there are no more events to | |
344 | * read (i.e. return bytes read, -EAGAIN or wait). | |
345 | */ | |
346 | ret = 0; | |
347 | } | |
348 | ||
d8aaab4f JK |
349 | /* |
350 | * Permission events get queued to wait for response. Other | |
351 | * events can be destroyed now. | |
352 | */ | |
a0a92d26 | 353 | if (!fanotify_is_perm_event(FANOTIFY_E(kevent)->mask)) { |
d8aaab4f | 354 | fsnotify_destroy_event(group, kevent); |
d507816b | 355 | } else { |
4ff33aaf | 356 | if (ret <= 0) { |
d507816b JK |
357 | FANOTIFY_PE(kevent)->response = FAN_DENY; |
358 | wake_up(&group->fanotify_data.access_waitq); | |
4ff33aaf AG |
359 | } else { |
360 | spin_lock(&group->notification_lock); | |
361 | list_add_tail(&kevent->list, | |
362 | &group->fanotify_data.access_list); | |
363 | spin_unlock(&group->notification_lock); | |
d507816b | 364 | } |
d507816b | 365 | } |
4ff33aaf AG |
366 | if (ret < 0) |
367 | break; | |
d8aaab4f JK |
368 | buf += ret; |
369 | count -= ret; | |
a1014f10 | 370 | } |
536ebe9c | 371 | remove_wait_queue(&group->notification_waitq, &wait); |
a1014f10 | 372 | |
a1014f10 EP |
373 | if (start != buf && ret != -EFAULT) |
374 | ret = buf - start; | |
375 | return ret; | |
376 | } | |
377 | ||
b2d87909 EP |
378 | static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
379 | { | |
b2d87909 EP |
380 | struct fanotify_response response = { .fd = -1, .response = -1 }; |
381 | struct fsnotify_group *group; | |
382 | int ret; | |
383 | ||
6685df31 MS |
384 | if (!IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS)) |
385 | return -EINVAL; | |
386 | ||
b2d87909 EP |
387 | group = file->private_data; |
388 | ||
389 | if (count > sizeof(response)) | |
390 | count = sizeof(response); | |
391 | ||
392 | pr_debug("%s: group=%p count=%zu\n", __func__, group, count); | |
393 | ||
394 | if (copy_from_user(&response, buf, count)) | |
395 | return -EFAULT; | |
396 | ||
397 | ret = process_access_response(group, &response); | |
398 | if (ret < 0) | |
399 | count = ret; | |
400 | ||
401 | return count; | |
b2d87909 EP |
402 | } |
403 | ||
52c923dd EP |
404 | static int fanotify_release(struct inode *ignored, struct file *file) |
405 | { | |
406 | struct fsnotify_group *group = file->private_data; | |
ca6f8699 | 407 | struct fanotify_perm_event *event; |
96d41019 | 408 | struct fsnotify_event *fsn_event; |
19ba54f4 | 409 | |
5838d444 | 410 | /* |
96d41019 JK |
411 | * Stop new events from arriving in the notification queue. since |
412 | * userspace cannot use fanotify fd anymore, no event can enter or | |
413 | * leave access_list by now either. | |
5838d444 | 414 | */ |
96d41019 | 415 | fsnotify_group_stop_queueing(group); |
2eebf582 | 416 | |
96d41019 JK |
417 | /* |
418 | * Process all permission events on access_list and notification queue | |
419 | * and simulate reply from userspace. | |
420 | */ | |
073f6552 | 421 | spin_lock(&group->notification_lock); |
ca6f8699 JK |
422 | while (!list_empty(&group->fanotify_data.access_list)) { |
423 | event = list_first_entry(&group->fanotify_data.access_list, | |
424 | struct fanotify_perm_event, fae.fse.list); | |
f083441b JK |
425 | list_del_init(&event->fae.fse.list); |
426 | event->response = FAN_ALLOW; | |
2eebf582 | 427 | } |
2eebf582 | 428 | |
5838d444 | 429 | /* |
96d41019 JK |
430 | * Destroy all non-permission events. For permission events just |
431 | * dequeue them and set the response. They will be freed once the | |
432 | * response is consumed and fanotify_get_response() returns. | |
5838d444 | 433 | */ |
96d41019 JK |
434 | while (!fsnotify_notify_queue_is_empty(group)) { |
435 | fsn_event = fsnotify_remove_first_event(group); | |
a0a92d26 | 436 | if (!(FANOTIFY_E(fsn_event)->mask & FANOTIFY_PERM_EVENTS)) { |
c21dbe20 | 437 | spin_unlock(&group->notification_lock); |
96d41019 | 438 | fsnotify_destroy_event(group, fsn_event); |
c21dbe20 | 439 | spin_lock(&group->notification_lock); |
6685df31 | 440 | } else { |
96d41019 | 441 | FANOTIFY_PE(fsn_event)->response = FAN_ALLOW; |
6685df31 | 442 | } |
96d41019 | 443 | } |
c21dbe20 | 444 | spin_unlock(&group->notification_lock); |
96d41019 JK |
445 | |
446 | /* Response for all permission events it set, wakeup waiters */ | |
2eebf582 | 447 | wake_up(&group->fanotify_data.access_waitq); |
0a6b6bd5 | 448 | |
52c923dd | 449 | /* matches the fanotify_init->fsnotify_alloc_group */ |
d8153d4d | 450 | fsnotify_destroy_group(group); |
52c923dd EP |
451 | |
452 | return 0; | |
453 | } | |
454 | ||
a1014f10 EP |
455 | static long fanotify_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
456 | { | |
457 | struct fsnotify_group *group; | |
7053aee2 | 458 | struct fsnotify_event *fsn_event; |
a1014f10 EP |
459 | void __user *p; |
460 | int ret = -ENOTTY; | |
461 | size_t send_len = 0; | |
462 | ||
463 | group = file->private_data; | |
464 | ||
465 | p = (void __user *) arg; | |
466 | ||
467 | switch (cmd) { | |
468 | case FIONREAD: | |
c21dbe20 | 469 | spin_lock(&group->notification_lock); |
7053aee2 | 470 | list_for_each_entry(fsn_event, &group->notification_list, list) |
a1014f10 | 471 | send_len += FAN_EVENT_METADATA_LEN; |
c21dbe20 | 472 | spin_unlock(&group->notification_lock); |
a1014f10 EP |
473 | ret = put_user(send_len, (int __user *) p); |
474 | break; | |
475 | } | |
476 | ||
477 | return ret; | |
478 | } | |
479 | ||
52c923dd | 480 | static const struct file_operations fanotify_fops = { |
be77196b | 481 | .show_fdinfo = fanotify_show_fdinfo, |
a1014f10 EP |
482 | .poll = fanotify_poll, |
483 | .read = fanotify_read, | |
b2d87909 | 484 | .write = fanotify_write, |
52c923dd EP |
485 | .fasync = NULL, |
486 | .release = fanotify_release, | |
a1014f10 EP |
487 | .unlocked_ioctl = fanotify_ioctl, |
488 | .compat_ioctl = fanotify_ioctl, | |
6038f373 | 489 | .llseek = noop_llseek, |
52c923dd EP |
490 | }; |
491 | ||
2a3edf86 EP |
492 | static int fanotify_find_path(int dfd, const char __user *filename, |
493 | struct path *path, unsigned int flags) | |
494 | { | |
495 | int ret; | |
496 | ||
497 | pr_debug("%s: dfd=%d filename=%p flags=%x\n", __func__, | |
498 | dfd, filename, flags); | |
499 | ||
500 | if (filename == NULL) { | |
2903ff01 | 501 | struct fd f = fdget(dfd); |
2a3edf86 EP |
502 | |
503 | ret = -EBADF; | |
2903ff01 | 504 | if (!f.file) |
2a3edf86 EP |
505 | goto out; |
506 | ||
507 | ret = -ENOTDIR; | |
508 | if ((flags & FAN_MARK_ONLYDIR) && | |
496ad9aa | 509 | !(S_ISDIR(file_inode(f.file)->i_mode))) { |
2903ff01 | 510 | fdput(f); |
2a3edf86 EP |
511 | goto out; |
512 | } | |
513 | ||
2903ff01 | 514 | *path = f.file->f_path; |
2a3edf86 | 515 | path_get(path); |
2903ff01 | 516 | fdput(f); |
2a3edf86 EP |
517 | } else { |
518 | unsigned int lookup_flags = 0; | |
519 | ||
520 | if (!(flags & FAN_MARK_DONT_FOLLOW)) | |
521 | lookup_flags |= LOOKUP_FOLLOW; | |
522 | if (flags & FAN_MARK_ONLYDIR) | |
523 | lookup_flags |= LOOKUP_DIRECTORY; | |
524 | ||
525 | ret = user_path_at(dfd, filename, lookup_flags, path); | |
526 | if (ret) | |
527 | goto out; | |
528 | } | |
529 | ||
530 | /* you can only watch an inode if you have read permissions on it */ | |
531 | ret = inode_permission(path->dentry->d_inode, MAY_READ); | |
532 | if (ret) | |
533 | path_put(path); | |
534 | out: | |
535 | return ret; | |
536 | } | |
537 | ||
b9e4e3bd EP |
538 | static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark, |
539 | __u32 mask, | |
6dfbd149 LS |
540 | unsigned int flags, |
541 | int *destroy) | |
088b09b0 | 542 | { |
d2c1874c | 543 | __u32 oldmask = 0; |
088b09b0 AG |
544 | |
545 | spin_lock(&fsn_mark->lock); | |
b9e4e3bd EP |
546 | if (!(flags & FAN_MARK_IGNORED_MASK)) { |
547 | oldmask = fsn_mark->mask; | |
a72fd224 | 548 | fsn_mark->mask &= ~mask; |
b9e4e3bd | 549 | } else { |
a72fd224 | 550 | fsn_mark->ignored_mask &= ~mask; |
b9e4e3bd | 551 | } |
a118449a | 552 | *destroy = !(fsn_mark->mask | fsn_mark->ignored_mask); |
088b09b0 AG |
553 | spin_unlock(&fsn_mark->lock); |
554 | ||
088b09b0 AG |
555 | return mask & oldmask; |
556 | } | |
557 | ||
eaa2c6b0 AG |
558 | static int fanotify_remove_mark(struct fsnotify_group *group, |
559 | fsnotify_connp_t *connp, __u32 mask, | |
560 | unsigned int flags) | |
88826276 EP |
561 | { |
562 | struct fsnotify_mark *fsn_mark = NULL; | |
088b09b0 | 563 | __u32 removed; |
6dfbd149 | 564 | int destroy_mark; |
88826276 | 565 | |
7b18527c | 566 | mutex_lock(&group->mark_mutex); |
eaa2c6b0 | 567 | fsn_mark = fsnotify_find_mark(connp, group); |
7b18527c LS |
568 | if (!fsn_mark) { |
569 | mutex_unlock(&group->mark_mutex); | |
f3640192 | 570 | return -ENOENT; |
7b18527c | 571 | } |
88826276 | 572 | |
6dfbd149 LS |
573 | removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags, |
574 | &destroy_mark); | |
3ac70bfc AG |
575 | if (removed & fsnotify_conn_mask(fsn_mark->connector)) |
576 | fsnotify_recalc_mask(fsn_mark->connector); | |
6dfbd149 | 577 | if (destroy_mark) |
4712e722 | 578 | fsnotify_detach_mark(fsn_mark); |
7b18527c | 579 | mutex_unlock(&group->mark_mutex); |
4712e722 JK |
580 | if (destroy_mark) |
581 | fsnotify_free_mark(fsn_mark); | |
6dfbd149 | 582 | |
eaa2c6b0 | 583 | /* matches the fsnotify_find_mark() */ |
f3640192 | 584 | fsnotify_put_mark(fsn_mark); |
f3640192 AG |
585 | return 0; |
586 | } | |
2a3edf86 | 587 | |
eaa2c6b0 AG |
588 | static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group, |
589 | struct vfsmount *mnt, __u32 mask, | |
590 | unsigned int flags) | |
591 | { | |
592 | return fanotify_remove_mark(group, &real_mount(mnt)->mnt_fsnotify_marks, | |
593 | mask, flags); | |
594 | } | |
595 | ||
d54f4fba AG |
596 | static int fanotify_remove_sb_mark(struct fsnotify_group *group, |
597 | struct super_block *sb, __u32 mask, | |
598 | unsigned int flags) | |
599 | { | |
600 | return fanotify_remove_mark(group, &sb->s_fsnotify_marks, mask, flags); | |
601 | } | |
602 | ||
f3640192 | 603 | static int fanotify_remove_inode_mark(struct fsnotify_group *group, |
b9e4e3bd EP |
604 | struct inode *inode, __u32 mask, |
605 | unsigned int flags) | |
f3640192 | 606 | { |
eaa2c6b0 AG |
607 | return fanotify_remove_mark(group, &inode->i_fsnotify_marks, mask, |
608 | flags); | |
2a3edf86 EP |
609 | } |
610 | ||
b9e4e3bd EP |
611 | static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark, |
612 | __u32 mask, | |
613 | unsigned int flags) | |
912ee394 | 614 | { |
192ca4d1 | 615 | __u32 oldmask = -1; |
912ee394 AG |
616 | |
617 | spin_lock(&fsn_mark->lock); | |
b9e4e3bd EP |
618 | if (!(flags & FAN_MARK_IGNORED_MASK)) { |
619 | oldmask = fsn_mark->mask; | |
a72fd224 | 620 | fsn_mark->mask |= mask; |
b9e4e3bd | 621 | } else { |
a72fd224 | 622 | fsn_mark->ignored_mask |= mask; |
c9778a98 EP |
623 | if (flags & FAN_MARK_IGNORED_SURV_MODIFY) |
624 | fsn_mark->flags |= FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY; | |
b9e4e3bd | 625 | } |
912ee394 AG |
626 | spin_unlock(&fsn_mark->lock); |
627 | ||
628 | return mask & ~oldmask; | |
629 | } | |
630 | ||
5e9c070c | 631 | static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group, |
b812a9f5 | 632 | fsnotify_connp_t *connp, |
77115225 AG |
633 | unsigned int type, |
634 | __kernel_fsid_t *fsid) | |
5e9c070c LS |
635 | { |
636 | struct fsnotify_mark *mark; | |
637 | int ret; | |
638 | ||
639 | if (atomic_read(&group->num_marks) > group->fanotify_data.max_marks) | |
640 | return ERR_PTR(-ENOSPC); | |
641 | ||
642 | mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL); | |
643 | if (!mark) | |
644 | return ERR_PTR(-ENOMEM); | |
645 | ||
054c636e | 646 | fsnotify_init_mark(mark, group); |
77115225 | 647 | ret = fsnotify_add_mark_locked(mark, connp, type, 0, fsid); |
5e9c070c LS |
648 | if (ret) { |
649 | fsnotify_put_mark(mark); | |
650 | return ERR_PTR(ret); | |
651 | } | |
652 | ||
653 | return mark; | |
654 | } | |
655 | ||
656 | ||
eaa2c6b0 AG |
657 | static int fanotify_add_mark(struct fsnotify_group *group, |
658 | fsnotify_connp_t *connp, unsigned int type, | |
77115225 AG |
659 | __u32 mask, unsigned int flags, |
660 | __kernel_fsid_t *fsid) | |
2a3edf86 EP |
661 | { |
662 | struct fsnotify_mark *fsn_mark; | |
912ee394 | 663 | __u32 added; |
2a3edf86 | 664 | |
7b18527c | 665 | mutex_lock(&group->mark_mutex); |
b812a9f5 | 666 | fsn_mark = fsnotify_find_mark(connp, group); |
88826276 | 667 | if (!fsn_mark) { |
77115225 | 668 | fsn_mark = fanotify_add_new_mark(group, connp, type, fsid); |
5e9c070c | 669 | if (IS_ERR(fsn_mark)) { |
7b18527c | 670 | mutex_unlock(&group->mark_mutex); |
5e9c070c | 671 | return PTR_ERR(fsn_mark); |
7b18527c | 672 | } |
88826276 | 673 | } |
b9e4e3bd | 674 | added = fanotify_mark_add_to_mask(fsn_mark, mask, flags); |
3ac70bfc AG |
675 | if (added & ~fsnotify_conn_mask(fsn_mark->connector)) |
676 | fsnotify_recalc_mask(fsn_mark->connector); | |
c9747640 | 677 | mutex_unlock(&group->mark_mutex); |
5e9c070c | 678 | |
fa218ab9 | 679 | fsnotify_put_mark(fsn_mark); |
5e9c070c | 680 | return 0; |
88826276 EP |
681 | } |
682 | ||
eaa2c6b0 AG |
683 | static int fanotify_add_vfsmount_mark(struct fsnotify_group *group, |
684 | struct vfsmount *mnt, __u32 mask, | |
77115225 | 685 | unsigned int flags, __kernel_fsid_t *fsid) |
eaa2c6b0 AG |
686 | { |
687 | return fanotify_add_mark(group, &real_mount(mnt)->mnt_fsnotify_marks, | |
77115225 | 688 | FSNOTIFY_OBJ_TYPE_VFSMOUNT, mask, flags, fsid); |
eaa2c6b0 AG |
689 | } |
690 | ||
d54f4fba | 691 | static int fanotify_add_sb_mark(struct fsnotify_group *group, |
77115225 AG |
692 | struct super_block *sb, __u32 mask, |
693 | unsigned int flags, __kernel_fsid_t *fsid) | |
d54f4fba AG |
694 | { |
695 | return fanotify_add_mark(group, &sb->s_fsnotify_marks, | |
77115225 | 696 | FSNOTIFY_OBJ_TYPE_SB, mask, flags, fsid); |
d54f4fba AG |
697 | } |
698 | ||
52202dfb | 699 | static int fanotify_add_inode_mark(struct fsnotify_group *group, |
b9e4e3bd | 700 | struct inode *inode, __u32 mask, |
77115225 | 701 | unsigned int flags, __kernel_fsid_t *fsid) |
88826276 | 702 | { |
88826276 | 703 | pr_debug("%s: group=%p inode=%p\n", __func__, group, inode); |
2a3edf86 | 704 | |
5322a59f EP |
705 | /* |
706 | * If some other task has this inode open for write we should not add | |
707 | * an ignored mark, unless that ignored mark is supposed to survive | |
708 | * modification changes anyway. | |
709 | */ | |
710 | if ((flags & FAN_MARK_IGNORED_MASK) && | |
711 | !(flags & FAN_MARK_IGNORED_SURV_MODIFY) && | |
ac9498d6 | 712 | inode_is_open_for_write(inode)) |
5322a59f EP |
713 | return 0; |
714 | ||
eaa2c6b0 | 715 | return fanotify_add_mark(group, &inode->i_fsnotify_marks, |
77115225 | 716 | FSNOTIFY_OBJ_TYPE_INODE, mask, flags, fsid); |
88826276 | 717 | } |
2a3edf86 | 718 | |
52c923dd | 719 | /* fanotify syscalls */ |
08ae8938 | 720 | SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) |
11637e4b | 721 | { |
52c923dd EP |
722 | struct fsnotify_group *group; |
723 | int f_flags, fd; | |
4afeff85 | 724 | struct user_struct *user; |
33913997 | 725 | struct fanotify_event *oevent; |
52c923dd | 726 | |
96a71f21 AG |
727 | pr_debug("%s: flags=%x event_f_flags=%x\n", |
728 | __func__, flags, event_f_flags); | |
52c923dd | 729 | |
52c923dd | 730 | if (!capable(CAP_SYS_ADMIN)) |
a2f13ad0 | 731 | return -EPERM; |
52c923dd | 732 | |
de8cd83e | 733 | #ifdef CONFIG_AUDITSYSCALL |
23c9deeb | 734 | if (flags & ~(FANOTIFY_INIT_FLAGS | FAN_ENABLE_AUDIT)) |
de8cd83e | 735 | #else |
23c9deeb | 736 | if (flags & ~FANOTIFY_INIT_FLAGS) |
de8cd83e | 737 | #endif |
52c923dd EP |
738 | return -EINVAL; |
739 | ||
48149e9d HS |
740 | if (event_f_flags & ~FANOTIFY_INIT_ALL_EVENT_F_BITS) |
741 | return -EINVAL; | |
742 | ||
743 | switch (event_f_flags & O_ACCMODE) { | |
744 | case O_RDONLY: | |
745 | case O_RDWR: | |
746 | case O_WRONLY: | |
747 | break; | |
748 | default: | |
749 | return -EINVAL; | |
750 | } | |
751 | ||
a8b13aa2 AG |
752 | if ((flags & FAN_REPORT_FID) && |
753 | (flags & FANOTIFY_CLASS_BITS) != FAN_CLASS_NOTIF) | |
754 | return -EINVAL; | |
755 | ||
4afeff85 EP |
756 | user = get_current_user(); |
757 | if (atomic_read(&user->fanotify_listeners) > FANOTIFY_DEFAULT_MAX_LISTENERS) { | |
758 | free_uid(user); | |
759 | return -EMFILE; | |
760 | } | |
761 | ||
b2d87909 | 762 | f_flags = O_RDWR | FMODE_NONOTIFY; |
52c923dd EP |
763 | if (flags & FAN_CLOEXEC) |
764 | f_flags |= O_CLOEXEC; | |
765 | if (flags & FAN_NONBLOCK) | |
766 | f_flags |= O_NONBLOCK; | |
767 | ||
768 | /* fsnotify_alloc_group takes a ref. Dropped in fanotify_release */ | |
769 | group = fsnotify_alloc_group(&fanotify_fsnotify_ops); | |
26379198 EP |
770 | if (IS_ERR(group)) { |
771 | free_uid(user); | |
52c923dd | 772 | return PTR_ERR(group); |
26379198 | 773 | } |
52c923dd | 774 | |
4afeff85 | 775 | group->fanotify_data.user = user; |
96a71f21 | 776 | group->fanotify_data.flags = flags; |
4afeff85 | 777 | atomic_inc(&user->fanotify_listeners); |
d46eb14b | 778 | group->memcg = get_mem_cgroup_from_mm(current->mm); |
4afeff85 | 779 | |
83b535d2 AG |
780 | oevent = fanotify_alloc_event(group, NULL, FS_Q_OVERFLOW, NULL, |
781 | FSNOTIFY_EVENT_NONE, NULL); | |
ff57cd58 JK |
782 | if (unlikely(!oevent)) { |
783 | fd = -ENOMEM; | |
784 | goto out_destroy_group; | |
785 | } | |
786 | group->overflow_event = &oevent->fse; | |
ff57cd58 | 787 | |
1e2ee49f WW |
788 | if (force_o_largefile()) |
789 | event_f_flags |= O_LARGEFILE; | |
80af2588 | 790 | group->fanotify_data.f_flags = event_f_flags; |
9e66e423 EP |
791 | init_waitqueue_head(&group->fanotify_data.access_waitq); |
792 | INIT_LIST_HEAD(&group->fanotify_data.access_list); | |
23c9deeb | 793 | switch (flags & FANOTIFY_CLASS_BITS) { |
4231a235 EP |
794 | case FAN_CLASS_NOTIF: |
795 | group->priority = FS_PRIO_0; | |
796 | break; | |
797 | case FAN_CLASS_CONTENT: | |
798 | group->priority = FS_PRIO_1; | |
799 | break; | |
800 | case FAN_CLASS_PRE_CONTENT: | |
801 | group->priority = FS_PRIO_2; | |
802 | break; | |
803 | default: | |
804 | fd = -EINVAL; | |
d8153d4d | 805 | goto out_destroy_group; |
4231a235 | 806 | } |
cb2d429f | 807 | |
5dd03f55 EP |
808 | if (flags & FAN_UNLIMITED_QUEUE) { |
809 | fd = -EPERM; | |
810 | if (!capable(CAP_SYS_ADMIN)) | |
d8153d4d | 811 | goto out_destroy_group; |
5dd03f55 EP |
812 | group->max_events = UINT_MAX; |
813 | } else { | |
814 | group->max_events = FANOTIFY_DEFAULT_MAX_EVENTS; | |
815 | } | |
2529a0df | 816 | |
ac7e22dc EP |
817 | if (flags & FAN_UNLIMITED_MARKS) { |
818 | fd = -EPERM; | |
819 | if (!capable(CAP_SYS_ADMIN)) | |
d8153d4d | 820 | goto out_destroy_group; |
ac7e22dc EP |
821 | group->fanotify_data.max_marks = UINT_MAX; |
822 | } else { | |
823 | group->fanotify_data.max_marks = FANOTIFY_DEFAULT_MAX_MARKS; | |
824 | } | |
e7099d8a | 825 | |
de8cd83e SG |
826 | if (flags & FAN_ENABLE_AUDIT) { |
827 | fd = -EPERM; | |
828 | if (!capable(CAP_AUDIT_WRITE)) | |
829 | goto out_destroy_group; | |
de8cd83e SG |
830 | } |
831 | ||
52c923dd EP |
832 | fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags); |
833 | if (fd < 0) | |
d8153d4d | 834 | goto out_destroy_group; |
52c923dd EP |
835 | |
836 | return fd; | |
837 | ||
d8153d4d LS |
838 | out_destroy_group: |
839 | fsnotify_destroy_group(group); | |
52c923dd | 840 | return fd; |
11637e4b | 841 | } |
bbaa4168 | 842 | |
a8b13aa2 | 843 | /* Check if filesystem can encode a unique fid */ |
73072283 | 844 | static int fanotify_test_fid(struct path *path, __kernel_fsid_t *fsid) |
a8b13aa2 | 845 | { |
73072283 | 846 | __kernel_fsid_t root_fsid; |
a8b13aa2 AG |
847 | int err; |
848 | ||
849 | /* | |
850 | * Make sure path is not in filesystem with zero fsid (e.g. tmpfs). | |
851 | */ | |
73072283 | 852 | err = vfs_get_fsid(path->dentry, fsid); |
a8b13aa2 AG |
853 | if (err) |
854 | return err; | |
855 | ||
73072283 | 856 | if (!fsid->val[0] && !fsid->val[1]) |
a8b13aa2 AG |
857 | return -ENODEV; |
858 | ||
859 | /* | |
860 | * Make sure path is not inside a filesystem subvolume (e.g. btrfs) | |
861 | * which uses a different fsid than sb root. | |
862 | */ | |
73072283 | 863 | err = vfs_get_fsid(path->dentry->d_sb->s_root, &root_fsid); |
a8b13aa2 AG |
864 | if (err) |
865 | return err; | |
866 | ||
73072283 AG |
867 | if (root_fsid.val[0] != fsid->val[0] || |
868 | root_fsid.val[1] != fsid->val[1]) | |
a8b13aa2 AG |
869 | return -EXDEV; |
870 | ||
871 | /* | |
872 | * We need to make sure that the file system supports at least | |
873 | * encoding a file handle so user can use name_to_handle_at() to | |
874 | * compare fid returned with event to the file handle of watched | |
875 | * objects. However, name_to_handle_at() requires that the | |
876 | * filesystem also supports decoding file handles. | |
877 | */ | |
878 | if (!path->dentry->d_sb->s_export_op || | |
879 | !path->dentry->d_sb->s_export_op->fh_to_dentry) | |
880 | return -EOPNOTSUPP; | |
881 | ||
882 | return 0; | |
883 | } | |
884 | ||
183caa3c DB |
885 | static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask, |
886 | int dfd, const char __user *pathname) | |
bbaa4168 | 887 | { |
0ff21db9 EP |
888 | struct inode *inode = NULL; |
889 | struct vfsmount *mnt = NULL; | |
2a3edf86 | 890 | struct fsnotify_group *group; |
2903ff01 | 891 | struct fd f; |
2a3edf86 | 892 | struct path path; |
73072283 | 893 | __kernel_fsid_t __fsid, *fsid = NULL; |
bdd5a46f | 894 | u32 valid_mask = FANOTIFY_EVENTS | FANOTIFY_EVENT_FLAGS; |
23c9deeb | 895 | unsigned int mark_type = flags & FANOTIFY_MARK_TYPE_BITS; |
2903ff01 | 896 | int ret; |
2a3edf86 EP |
897 | |
898 | pr_debug("%s: fanotify_fd=%d flags=%x dfd=%d pathname=%p mask=%llx\n", | |
899 | __func__, fanotify_fd, flags, dfd, pathname, mask); | |
900 | ||
901 | /* we only use the lower 32 bits as of right now. */ | |
902 | if (mask & ((__u64)0xffffffff << 32)) | |
903 | return -EINVAL; | |
904 | ||
23c9deeb | 905 | if (flags & ~FANOTIFY_MARK_FLAGS) |
88380fe6 | 906 | return -EINVAL; |
d54f4fba AG |
907 | |
908 | switch (mark_type) { | |
909 | case FAN_MARK_INODE: | |
910 | case FAN_MARK_MOUNT: | |
911 | case FAN_MARK_FILESYSTEM: | |
912 | break; | |
913 | default: | |
914 | return -EINVAL; | |
915 | } | |
916 | ||
4d92604c | 917 | switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) { |
1734dee4 | 918 | case FAN_MARK_ADD: /* fallthrough */ |
88380fe6 | 919 | case FAN_MARK_REMOVE: |
1734dee4 LS |
920 | if (!mask) |
921 | return -EINVAL; | |
cc299a98 | 922 | break; |
4d92604c | 923 | case FAN_MARK_FLUSH: |
23c9deeb | 924 | if (flags & ~(FANOTIFY_MARK_TYPE_BITS | FAN_MARK_FLUSH)) |
cc299a98 | 925 | return -EINVAL; |
88380fe6 AG |
926 | break; |
927 | default: | |
928 | return -EINVAL; | |
929 | } | |
8fcd6528 | 930 | |
6685df31 | 931 | if (IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS)) |
23c9deeb | 932 | valid_mask |= FANOTIFY_PERM_EVENTS; |
6685df31 MS |
933 | |
934 | if (mask & ~valid_mask) | |
2a3edf86 EP |
935 | return -EINVAL; |
936 | ||
2903ff01 AV |
937 | f = fdget(fanotify_fd); |
938 | if (unlikely(!f.file)) | |
2a3edf86 EP |
939 | return -EBADF; |
940 | ||
941 | /* verify that this is indeed an fanotify instance */ | |
942 | ret = -EINVAL; | |
2903ff01 | 943 | if (unlikely(f.file->f_op != &fanotify_fops)) |
2a3edf86 | 944 | goto fput_and_out; |
2903ff01 | 945 | group = f.file->private_data; |
4231a235 EP |
946 | |
947 | /* | |
948 | * group->priority == FS_PRIO_0 == FAN_CLASS_NOTIF. These are not | |
949 | * allowed to set permissions events. | |
950 | */ | |
951 | ret = -EINVAL; | |
23c9deeb | 952 | if (mask & FANOTIFY_PERM_EVENTS && |
4231a235 EP |
953 | group->priority == FS_PRIO_0) |
954 | goto fput_and_out; | |
2a3edf86 | 955 | |
235328d1 AG |
956 | /* |
957 | * Events with data type inode do not carry enough information to report | |
958 | * event->fd, so we do not allow setting a mask for inode events unless | |
959 | * group supports reporting fid. | |
960 | * inode events are not supported on a mount mark, because they do not | |
961 | * carry enough information (i.e. path) to be filtered by mount point. | |
962 | */ | |
963 | if (mask & FANOTIFY_INODE_EVENTS && | |
964 | (!FAN_GROUP_FLAG(group, FAN_REPORT_FID) || | |
965 | mark_type == FAN_MARK_MOUNT)) | |
966 | goto fput_and_out; | |
967 | ||
0a8dd2db HS |
968 | if (flags & FAN_MARK_FLUSH) { |
969 | ret = 0; | |
d54f4fba | 970 | if (mark_type == FAN_MARK_MOUNT) |
0a8dd2db | 971 | fsnotify_clear_vfsmount_marks_by_group(group); |
d54f4fba AG |
972 | else if (mark_type == FAN_MARK_FILESYSTEM) |
973 | fsnotify_clear_sb_marks_by_group(group); | |
0a8dd2db HS |
974 | else |
975 | fsnotify_clear_inode_marks_by_group(group); | |
976 | goto fput_and_out; | |
977 | } | |
978 | ||
2a3edf86 EP |
979 | ret = fanotify_find_path(dfd, pathname, &path, flags); |
980 | if (ret) | |
981 | goto fput_and_out; | |
982 | ||
a8b13aa2 | 983 | if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { |
73072283 | 984 | ret = fanotify_test_fid(&path, &__fsid); |
a8b13aa2 AG |
985 | if (ret) |
986 | goto path_put_and_out; | |
77115225 | 987 | |
73072283 | 988 | fsid = &__fsid; |
a8b13aa2 AG |
989 | } |
990 | ||
2a3edf86 | 991 | /* inode held in place by reference to path; group by fget on fd */ |
d54f4fba | 992 | if (mark_type == FAN_MARK_INODE) |
0ff21db9 EP |
993 | inode = path.dentry->d_inode; |
994 | else | |
995 | mnt = path.mnt; | |
2a3edf86 EP |
996 | |
997 | /* create/update an inode mark */ | |
0a8dd2db | 998 | switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE)) { |
c6223f46 | 999 | case FAN_MARK_ADD: |
d54f4fba | 1000 | if (mark_type == FAN_MARK_MOUNT) |
77115225 AG |
1001 | ret = fanotify_add_vfsmount_mark(group, mnt, mask, |
1002 | flags, fsid); | |
d54f4fba | 1003 | else if (mark_type == FAN_MARK_FILESYSTEM) |
77115225 AG |
1004 | ret = fanotify_add_sb_mark(group, mnt->mnt_sb, mask, |
1005 | flags, fsid); | |
0ff21db9 | 1006 | else |
77115225 AG |
1007 | ret = fanotify_add_inode_mark(group, inode, mask, |
1008 | flags, fsid); | |
c6223f46 AG |
1009 | break; |
1010 | case FAN_MARK_REMOVE: | |
d54f4fba | 1011 | if (mark_type == FAN_MARK_MOUNT) |
77115225 AG |
1012 | ret = fanotify_remove_vfsmount_mark(group, mnt, mask, |
1013 | flags); | |
d54f4fba | 1014 | else if (mark_type == FAN_MARK_FILESYSTEM) |
77115225 AG |
1015 | ret = fanotify_remove_sb_mark(group, mnt->mnt_sb, mask, |
1016 | flags); | |
f3640192 | 1017 | else |
77115225 AG |
1018 | ret = fanotify_remove_inode_mark(group, inode, mask, |
1019 | flags); | |
c6223f46 AG |
1020 | break; |
1021 | default: | |
1022 | ret = -EINVAL; | |
1023 | } | |
2a3edf86 | 1024 | |
a8b13aa2 | 1025 | path_put_and_out: |
2a3edf86 EP |
1026 | path_put(&path); |
1027 | fput_and_out: | |
2903ff01 | 1028 | fdput(f); |
2a3edf86 EP |
1029 | return ret; |
1030 | } | |
1031 | ||
183caa3c DB |
1032 | SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags, |
1033 | __u64, mask, int, dfd, | |
1034 | const char __user *, pathname) | |
1035 | { | |
1036 | return do_fanotify_mark(fanotify_fd, flags, mask, dfd, pathname); | |
1037 | } | |
1038 | ||
91c2e0bc AV |
1039 | #ifdef CONFIG_COMPAT |
1040 | COMPAT_SYSCALL_DEFINE6(fanotify_mark, | |
1041 | int, fanotify_fd, unsigned int, flags, | |
1042 | __u32, mask0, __u32, mask1, int, dfd, | |
1043 | const char __user *, pathname) | |
1044 | { | |
183caa3c | 1045 | return do_fanotify_mark(fanotify_fd, flags, |
91c2e0bc | 1046 | #ifdef __BIG_ENDIAN |
91c2e0bc | 1047 | ((__u64)mask0 << 32) | mask1, |
592f6b84 HC |
1048 | #else |
1049 | ((__u64)mask1 << 32) | mask0, | |
91c2e0bc AV |
1050 | #endif |
1051 | dfd, pathname); | |
1052 | } | |
1053 | #endif | |
1054 | ||
2a3edf86 | 1055 | /* |
ae0e47f0 | 1056 | * fanotify_user_setup - Our initialization function. Note that we cannot return |
2a3edf86 EP |
1057 | * error because we have compiled-in VFS hooks. So an (unlikely) failure here |
1058 | * must result in panic(). | |
1059 | */ | |
1060 | static int __init fanotify_user_setup(void) | |
1061 | { | |
a8b13aa2 | 1062 | BUILD_BUG_ON(HWEIGHT32(FANOTIFY_INIT_FLAGS) != 8); |
bdd5a46f AG |
1063 | BUILD_BUG_ON(HWEIGHT32(FANOTIFY_MARK_FLAGS) != 9); |
1064 | ||
d46eb14b SB |
1065 | fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, |
1066 | SLAB_PANIC|SLAB_ACCOUNT); | |
33913997 | 1067 | fanotify_event_cachep = KMEM_CACHE(fanotify_event, SLAB_PANIC); |
6685df31 MS |
1068 | if (IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS)) { |
1069 | fanotify_perm_event_cachep = | |
33913997 | 1070 | KMEM_CACHE(fanotify_perm_event, SLAB_PANIC); |
6685df31 | 1071 | } |
2a3edf86 EP |
1072 | |
1073 | return 0; | |
bbaa4168 | 1074 | } |
2a3edf86 | 1075 | device_initcall(fanotify_user_setup); |