From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 25 Aug 2010 23:44:35 +0000 (+0000)
Subject: l2tp: test for ethernet header in l2tp_eth_dev_recv()
X-Git-Tag: v2.6.35.6~65
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2974d51279e5437f5b34a5163d1d835586488946;p=karo-tx-linux.git

l2tp: test for ethernet header in l2tp_eth_dev_recv()

[ Upstream commit bfc960a8eec023a170a80697fe65157cd4f44f81 ]

close https://bugzilla.kernel.org/show_bug.cgi?id=16529

Before calling dev_forward_skb(), we should make sure skb head contains
at least an ethernet header, even if length included in upper layer said
so. Use pskb_may_pull() to make sure this ethernet header is present in
skb head.

Reported-by: Thomas Heil <heil@terminal-consulting.de>
Reported-by: Ian Campbell <Ian.Campbell@eu.citrix.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
index 58c6c4cda73b..1ae697681bc7 100644
--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -132,7 +132,7 @@ static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb,
 		printk("\n");
 	}
 
-	if (data_len < ETH_HLEN)
+	if (!pskb_may_pull(skb, sizeof(ETH_HLEN)))
 		goto error;
 
 	secpath_reset(skb);