Re: [Bugme-new] [Bug 16529] New: xennet driver crashes when using with pseudowire aka l2tpv3

[Eric Dumazet <eric.dumazet@gmail.com>]

Here is the patch, could you test it please ?

Thanks !

[PATCH] l2tp: test for malicious frames in l2tp_eth_dev_recv()

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

Before calling dev_forward_skb(), we should make sure skb contains at
least an ethernet header, even if length included in upper layer said
so.

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>
---
 net/l2tp/l2tp_core.c |    2 +-
 net/l2tp/l2tp_eth.c  |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
index 58c6c4c..0687c5c 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 (skb->len < ETH_HLEN)
 		goto error;
 
 	secpath_reset(skb);