From 5d4bafa7be0843b63b6368ae49aaf0f5a941fc9f Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 19 Jan 2015 11:48:45 -0600 Subject: mnt: Fix the error check in __detach_mounts [ Upstream commit f53e57975151f54ad8caa1b0ac8a78091cd5700a ] lookup_mountpoint can return either NULL or an error value. Update the test in __detach_mounts to test for an error value to avoid pathological cases causing a NULL pointer dereferences. The callers of __detach_mounts should prevent it from ever being called on an unlinked dentry but don't take any chances. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" Signed-off-by: Sasha Levin --- fs/namespace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/namespace.c b/fs/namespace.c index 8b60287a488b..a19d05c4ebe5 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1490,7 +1490,7 @@ void __detach_mounts(struct dentry *dentry) namespace_lock(); mp = lookup_mountpoint(dentry); - if (!mp) + if (IS_ERR_OR_NULL(mp)) goto out_unlock; lock_mount_hash(); -- cgit v1.2.3