From 4396a73115fc8739083536162e2228c0c0c3ed1a Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Thu, 9 Sep 2021 14:56:34 +0300 Subject: [PATCH] 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: ec44610fe2b8 ("fsnotify: count all objects with attached connectors") Reported-by: Murphy Zhou Link: https://lore.kernel.org/linux-fsdevel/20210907063338.ycaw6wvhzrfsfdlp@xzhoux.usersys.redhat.com/ Signed-off-by: Amir Goldstein Signed-off-by: Linus Torvalds --- fs/notify/mark.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/notify/mark.c b/fs/notify/mark.c index 95006d1d29ab..fa1d99101f89 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -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); } -- 2.20.1