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

parents 2d65a9f4 0d082601

fs/namespace.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -2915,6 +2915,9 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
		/* 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);