[3.16.y-ckt stable] Patch "xen-blkback: fix leak on grant map error path" has been added to staging queue

[Luis Henriques]

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

    xen-blkback: fix leak on grant map error path

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt2.

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

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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>From fea6ccb68d5f98972dea30055b6e5ee7e413036d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= <roger.pau at citrix.com>
Date: Mon, 15 Sep 2014 11:55:27 +0200
Subject: xen-blkback: fix leak on grant map error path
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

commit 61cecca865280bef4f8a9748d0a9afa5df351ac2 upstream.

Fix leaking a page when a grant mapping has failed.

Signed-off-by: Roger Pau Monné <roger.pau at citrix.com>
Reported-and-Tested-by: Tao Chen <boby.chen at huawei.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/block/xen-blkback/blkback.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 64c60edcdfbc..63fc7f06a014 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -763,6 +763,7 @@ again:
 			BUG_ON(new_map_idx >= segs_to_map);
 			if (unlikely(map[new_map_idx].status != 0)) {
 				pr_debug(DRV_PFX "invalid buffer -- could not remap it\n");
+				put_free_pages(blkif, &pages[seg_idx]->page, 1);
 				pages[seg_idx]->handle = BLKBACK_INVALID_HANDLE;
 				ret |= 1;
 				goto next;
--
2.1.0