This patch fixes an userspace triggered oops. If there is no ICMP_ID
info the reference to attr will be NULL.

Signed-off-by: Krzysztof Piotr Oledzki <ole@ans.pl>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

--- a/net/ipv4/netfilter/ip_conntrack_proto_icmp.c	2005-11-06 02:17:29.000000000 +0100
+++ b/net/ipv4/netfilter/ip_conntrack_proto_icmp.c	2005-11-06 02:18:45.000000000 +0100
@@ -296,7 +296,8 @@
 				struct ip_conntrack_tuple *tuple)
 {
 	if (!tb[CTA_PROTO_ICMP_TYPE-1]
-	    || !tb[CTA_PROTO_ICMP_CODE-1])
+	    || !tb[CTA_PROTO_ICMP_CODE-1]
+	    || !tb[CTA_PROTO_ICMP_ID-1])
 		return -1;
 
 	tuple->dst.u.icmp.type =