Commit 9cf90cef authored Oct 31, 2017 by Jan Kara

fsnotify: Protect bail out path of fsnotify_add_mark_locked() properly



When fsnotify_add_mark_locked() fails it cleans up the mark it was
adding. Since the mark is already visible in group's list, we should
protect update of mark->flags with mark->lock. I'm not aware of any real
issues this could cause (since we also hold group->mark_mutex) but
better be safe and obey locking rules properly.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

parent b3a00660

fs/notify/mark.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -599,9 +599,11 @@ int fsnotify_add_mark_locked(struct fsnotify_mark mark, struct inode inode,

		return ret;
		err:
		spin_lock(&mark->lock);
		mark->flags &= ~(FSNOTIFY_MARK_FLAG_ALIVE \|
		FSNOTIFY_MARK_FLAG_ATTACHED);
		list_del_init(&mark->g_list);
		spin_unlock(&mark->lock);
		atomic_dec(&group->num_marks);

		fsnotify_put_mark(mark);