linux/fs/notify
Amir Goldstein b469e7e47c fanotify: fix handling of events on child sub-directory
When an event is reported on a sub-directory and the parent inode has
a mark mask with FS_EVENT_ON_CHILD|FS_ISDIR, the event will be sent to
fsnotify() even if the event type is not in the parent mark mask
(e.g. FS_OPEN).

Further more, if that event happened on a mount or a filesystem with
a mount/sb mark that does have that event type in their mask, the "on
child" event will be reported on the mount/sb mark.  That is not
desired, because user will get a duplicate event for the same action.

Note that the event reported on the victim inode is never merged with
the event reported on the parent inode, because of the check in
should_merge(): old_fsn->inode == new_fsn->inode.

Fix this by looking for a match of an actual event type (i.e. not just
FS_ISDIR) in parent's inode mark mask and by not reporting an "on child"
event to group if event type is only found on mount/sb marks.

[backport hint: The bug seems to have always been in fanotify, but this
                patch will only apply cleanly to v4.19.y]

Cc: <stable@vger.kernel.org> # v4.19
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-11-08 15:43:48 +01:00
..
dnotify Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-08-21 13:47:29 -07:00
fanotify fanotify: fix handling of events on child sub-directory 2018-11-08 15:43:48 +01:00
inotify fsnotify: convert runtime BUG_ON() to BUILD_BUG_ON() 2018-10-04 13:28:50 +02:00
Kconfig rcu: Make SRCU optional by using CONFIG_SRCU 2015-01-06 11:04:29 -08:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fdinfo.c fanotify: store fanotify_init() flags in group's fanotify_data 2018-09-27 15:29:00 +02:00
fdinfo.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fsnotify.c fanotify: fix handling of events on child sub-directory 2018-11-08 15:43:48 +01:00
fsnotify.h fsnotify: add super block object type 2018-09-03 15:14:01 +02:00
group.c fs: fsnotify: account fsnotify metadata to kmemcg 2018-08-17 16:20:30 -07:00
mark.c fsnotify: Fix busy inodes during unmount 2018-10-25 15:49:19 +02:00
notification.c fsnotify: Let userspace know about lost events due to ENOMEM 2018-02-27 10:25:33 +01:00