Commit 4396a731 authored by Amir Goldstein's avatar Amir Goldstein Committed by Linus Torvalds
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fsnotify: fix sb_connectors leak 



Fix a leak in s_fsnotify_connectors counter in case of a race between
concurrent add of new fsnotify mark to an object.

The task that lost the race fails to drop the counter before freeing
the unused connector.

Following umount() hangs in fsnotify_sb_delete()/wait_var_event(),
because s_fsnotify_connectors never drops to zero.

Fixes: ec44610f ("fsnotify: count all objects with attached connectors")
Reported-by: default avatarMurphy Zhou <jencce.kernel@gmail.com>
Link: https://lore.kernel.org/linux-fsdevel/20210907063338.ycaw6wvhzrfsfdlp@xzhoux.usersys.redhat.com/


Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent bf9f243f

fs/notify/mark.c

+1 −0
Original line number Diff line number Diff line
@@ -531,6 +531,7 @@ static int fsnotify_attach_connector_to_object(fsnotify_connp_t *connp, 
		/* Someone else created list structure for us */

		if (inode)

			fsnotify_put_inode_ref(inode);

		fsnotify_put_sb_connectors(conn);

		kmem_cache_free(fsnotify_mark_connector_cachep, conn);

	}