[3.11.y.z extended stable] Patch "8021q: fix a potential memory leak" has been added to staging queue

[Luis Henriques]

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

    8021q: fix a potential memory leak

to the linux-3.11.y-queue branch of the 3.11.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-3.11.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 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From cd2b1102996f2b021490b429cd04c66ec9031842 Mon Sep 17 00:00:00 2001
From: Li RongQing <roy.qing.li at gmail.com>
Date: Wed, 18 Jun 2014 13:46:02 +0800
Subject: 8021q: fix a potential memory leak

commit 916c1689a09bc1ca81f2d7a34876f8d35aadd11b upstream.

skb_cow called in vlan_reorder_header does not free the skb when it failed,
and vlan_reorder_header returns NULL to reset original skb when it is called
in vlan_untag, lead to a memory leak.

Signed-off-by: Li RongQing <roy.qing.li at gmail.com>
Acked-by: Eric Dumazet <edumazet at google.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/8021q/vlan_core.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c
index 6ee48aac776f..7e57135c7cc4 100644
--- a/net/8021q/vlan_core.c
+++ b/net/8021q/vlan_core.c
@@ -108,8 +108,11 @@ EXPORT_SYMBOL(vlan_dev_vlan_id);

 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
 {
-	if (skb_cow(skb, skb_headroom(skb)) < 0)
+	if (skb_cow(skb, skb_headroom(skb)) < 0) {
+		kfree_skb(skb);
 		return NULL;
+	}
+
 	memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
 	skb->mac_header += VLAN_HLEN;
 	return skb;
--
1.9.1