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