--- /dev/null
+--- a/net/ipv4/netfilter/ip_tables.c
++++ b/net/ipv4/netfilter/ip_tables.c
+@@ -85,9 +85,11 @@ ip_packet_match(const struct iphdr *ip,
+ if (ipinfo->flags & IPT_F_NO_DEF_MATCH)
+ return true;
+
+- if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
++ if (FWINV(ipinfo->smsk.s_addr &&
++ (ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
+ IPT_INV_SRCIP) ||
+- FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
++ FWINV(ipinfo->dmsk.s_addr &&
++ (ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
+ IPT_INV_DSTIP)) {
+ dprintf("Source or dest mismatch.\n");
+