[ 20/22] bridge: Pull ip header into skb->data before looking into ip header.

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.0-stable review patch.  If anyone has any objections, please let me know.

------------------


From: Sarveshwar Bandi <sarveshwar.bandi@emulex.com>

[ Upstream commit 6caab7b0544e83e6c160b5e80f5a4a7dd69545c7 ]

If lower layer driver leaves the ip header in the skb fragment, it needs to
be first pulled into skb->data before inspecting ip header length or ip version
number.

Signed-off-by: Sarveshwar Bandi <sarveshwar.bandi@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/bridge/br_netfilter.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -233,6 +233,9 @@ static int br_parse_ip_options(struct sk
 	struct net_device *dev = skb->dev;
 	u32 len;
 
+	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+		goto inhdr_error;
+
 	iph = ip_hdr(skb);
 	opt = &(IPCB(skb)->opt);