From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail177-1.suw61.mandrillapp.com ([198.2.177.1]:9173 "EHLO mail177-1.suw61.mandrillapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753203AbcCATu3 (ORCPT ); Tue, 1 Mar 2016 14:50:29 -0500 Received: from pmta06.mandrill.prod.suw01.rsglab.com (127.0.0.1) by mail177-1.suw61.mandrillapp.com id hqnp8a22rtkl for ; Tue, 1 Mar 2016 19:50:10 +0000 (envelope-from ) From: Subject: Patch "virtio_balloon: fix race by fill and leak" has been added to the 4.4-stable tree To: , , Cc: , Message-Id: <1456861804198218@kroah.com> Date: Tue, 01 Mar 2016 19:50:10 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled virtio_balloon: fix race by fill and leak to the 4.4-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: virtio_balloon-fix-race-by-fill-and-leak.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From f68b992bbb474641881932c61c92dcfa6f5b3689 Mon Sep 17 00:00:00 2001 From: Minchan Kim Date: Mon, 28 Dec 2015 08:35:12 +0900 Subject: virtio_balloon: fix race by fill and leak From: Minchan Kim commit f68b992bbb474641881932c61c92dcfa6f5b3689 upstream. During my compaction-related stuff, I encountered a bug with ballooning. With repeated inflating and deflating cycle, guest memory( ie, cat /proc/meminfo | grep MemTotal) is decreased and couldn't be recovered. The reason is balloon_lock doesn't cover release_pages_balloon so struct virtio_balloon fields could be overwritten by race of fill_balloon(e,g, vb->*pfns could be critical). This patch fixes it in my test. Signed-off-by: Minchan Kim Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman --- drivers/virtio/virtio_balloon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -209,8 +209,8 @@ static unsigned leak_balloon(struct virt */ if (vb->num_pfns != 0) tell_host(vb, vb->deflate_vq); - mutex_unlock(&vb->balloon_lock); release_pages_balloon(vb); + mutex_unlock(&vb->balloon_lock); return num_freed_pages; } Patches currently in stable-queue which might be from minchan@kernel.org are queue-4.4/virtio_balloon-fix-race-by-fill-and-leak.patch queue-4.4/virtio_balloon-fix-race-between-migration-and-ballooning.patch