bridge: Pull ip header into skb->data before looking into ip header.

[ 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: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index 577ea5d..7c1745d 100644 (file)
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -245,6 +245,9 @@ static int br_parse_ip_options(struct sk_buff *skb)
        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);