[3.8.y.z extended stable] Patch "devpts: plug the memory leak in kill_sb" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    devpts: plug the memory leak in kill_sb

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.14.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 27122f6a34679cf76b1217dca3f085d3f4230a50 Mon Sep 17 00:00:00 2001
From: Ilija Hadzic <ihadzic at research.bell-labs.com>
Date: Tue, 12 Nov 2013 15:11:45 -0800
Subject: devpts: plug the memory leak in kill_sb

commit 66da0e1f9034140ae2f571ef96e254a25083906c upstream.

When devpts is unmounted, there may be a no-longer-used IDR tree hanging
off the superblock we are about to kill.  This needs to be cleaned up
before destroying the SB.

The leak is usually not a big deal because unmounting devpts is typically
done when shutting down the whole machine.  However, shutting down an LXC
container instead of a physical machine exposes the problem (the garbage
is detectable with kmemleak).

Signed-off-by: Ilija Hadzic <ihadzic at research.bell-labs.com>
Cc: Sukadev Bhattiprolu <sukadev at linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 fs/devpts/inode.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index 472e6be..1d24d57 100644
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -483,6 +483,7 @@ static void devpts_kill_sb(struct super_block *sb)
 {
 	struct pts_fs_info *fsi = DEVPTS_SB(sb);

+	ida_destroy(&fsi->allocated_ptys);
 	kfree(fsi);
 	kill_litter_super(sb);
 }
--
1.8.3.2