Merge branch 'CVE-2014-7970' of git://git.kernel.org/pub/scm/linux/kernel/git/luto/linux
Pull pivot_root() fix from Andy Lutomirski.
Prevent a leak of unreachable mounts.
* 'CVE-2014-7970' of git://git.kernel.org/pub/scm/linux/kernel/git/luto/linux:
mnt: Prevent pivot_root from creating a loop in the mount tree
diff --git a/fs/namespace.c b/fs/namespace.c
index 2651328..fbba8b1 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2915,6 +2915,9 @@
/* make sure we can reach put_old from new_root */
if (!is_path_reachable(old_mnt, old.dentry, &new))
goto out4;
+ /* make certain new is below the root */
+ if (!is_path_reachable(new_mnt, new.dentry, &root))
+ goto out4;
root_mp->m_count++; /* pin it so it won't go away */
lock_mount_hash();
detach_mnt(new_mnt, &parent_path);
