[15/80] l2tp: test for ethernet header in l2tp_eth_dev_recv()

Greg KH
2010-09-24T16:59:01Z

From: Eric Dumazet <eric.dumazet@gmail.com>

[ 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>
---
net/l2tp/l2tp_eth.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -132,7 +132,7 @@ static void l2tp_eth_dev_recv(struct l2t
printk("\n");
}

- if (data_len < ETH_HLEN)
+ if (!pskb_may_pull(skb, sizeof(ETH_HLEN)))
goto error;

secpath_reset(skb);