[ 3.5.y.z extended stable ] Patch "xen/netback: free already allocated memory on failure in" has been added to staging queue

[Herton Ronaldo Krzesinski]

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

    xen/netback: free already allocated memory on failure in

to the linux-3.5.y-queue branch of the 3.5.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-3.5.y-queue

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

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

>From c4ecfd873c2c0aca1ba0a50d7217d871334bf78a Mon Sep 17 00:00:00 2001
From: Ian Campbell <Ian.Campbell at citrix.com>
Date: Wed, 6 Feb 2013 23:41:37 +0000
Subject: [PATCH] xen/netback: free already allocated memory on failure in
 xen_netbk_get_requests

commit 4cc7c1cb7b11b6f3515bd9075527576a1eecc4aa upstream.

Signed-off-by: Ian Campbell <ian.campbell at citrix.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 drivers/net/xen-netback/netback.c |   13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index e7913e0..c503a58 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -949,7 +949,7 @@ static struct gnttab_copy *xen_netbk_get_requests(struct xen_netbk *netbk,
 		pending_idx = netbk->pending_ring[index];
 		page = xen_netbk_alloc_page(netbk, skb, pending_idx);
 		if (!page)
-			return NULL;
+			goto err;

 		gop->source.u.ref = txp->gref;
 		gop->source.domid = vif->domid;
@@ -971,6 +971,17 @@ static struct gnttab_copy *xen_netbk_get_requests(struct xen_netbk *netbk,
 	}

 	return gop;
+err:
+	/* Unwind, freeing all pages and sending error responses. */
+	while (i-- > start) {
+		xen_netbk_idx_release(netbk, frag_get_pending_idx(&frags[i]),
+				      XEN_NETIF_RSP_ERROR);
+	}
+	/* The head too, if necessary. */
+	if (start)
+		xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_ERROR);
+
+	return NULL;
 }

 static int xen_netbk_tx_check_gop(struct xen_netbk *netbk,
--
1.7.9.5