Commit 5d4bafa7 authored Jan 19, 2015 by Eric W. Biederman Committed by Sasha Levin Jun 28, 2015

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" <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

parent f9c3700b

fs/namespace.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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();