Patch "mnt: Fix fs_fully_visible to verify the root directory is visible" has been added to the 4.0-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    mnt: Fix fs_fully_visible to verify the root directory is visible

to the 4.0-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mnt-fix-fs_fully_visible-to-verify-the-root-directory-is-visible.patch
and it can be found in the queue-4.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 7e96c1b0e0f495c5a7450dc4aa7c9a24ba4305bd Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm@xmission.com>
Date: Fri, 8 May 2015 16:36:50 -0500
Subject: mnt: Fix fs_fully_visible to verify the root directory is visible

From: "Eric W. Biederman" <ebiederm@xmission.com>

commit 7e96c1b0e0f495c5a7450dc4aa7c9a24ba4305bd upstream.

This fixes a dumb bug in fs_fully_visible that allows proc or sys to
be mounted if there is a bind mount of part of /proc/ or /sys/ visible.

Reported-by: Eric Windisch <ewindisch@docker.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/namespace.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -3178,6 +3178,12 @@ bool fs_fully_visible(struct file_system
 		if (mnt->mnt.mnt_sb->s_type != type)
 			continue;
 
+		/* This mount is not fully visible if it's root directory
+		 * is not the root directory of the filesystem.
+		 */
+		if (mnt->mnt.mnt_root != mnt->mnt.mnt_sb->s_root)
+			continue;
+
 		/* This mount is not fully visible if there are any child mounts
 		 * that cover anything except for empty directories.
 		 */


Patches currently in stable-queue which might be from ebiederm@xmission.com are

queue-4.0/mnt-fix-fs_fully_visible-to-verify-the-root-directory-is-visible.patch