WSL2-Linux-Kernel/fs/notify
Amir Goldstein 515160e3c4 fanotify: fix handling of events on child sub-directory
commit b469e7e47c upstream.

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>
[amir: backport to v4.9]
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06 17:31:37 +01:00
..
dnotify dnotify: Handle errors from fsnotify_add_mark_locked() in fcntl_dirnotify() 2018-02-25 11:07:47 +01:00
fanotify fanotify: fix logic of events on child 2018-04-24 09:36:38 +02:00
inotify License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
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 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
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 2019-02-06 17:31:37 +01:00
fsnotify.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
group.c fsnotify: Remove fsnotify_detach_group_marks() 2017-04-10 17:37:36 +02:00
mark.c fsnotify: fix pinning group in fsnotify_prepare_user_wait() 2017-11-30 08:40:47 +00:00
notification.c fsnotify: clean up spinlock assertions 2016-10-07 18:46:26 -07:00