--- /dev/null
+diff -ur iptables-1.4.3.2.orig/xtables.c iptables-1.4.3.2/xtables.c
+--- iptables-1.4.3.2.orig/xtables.c 2009-05-03 16:17:53.000000000 +0200
++++ iptables-1.4.3.2/xtables.c 2009-05-03 16:27:37.000000000 +0200
+@@ -1502,7 +1502,8 @@
+ else {
+ unsigned int i;
+ for (i = 0; i < ARRAY_SIZE(xtables_chain_protos); ++i) {
+- if (strcmp(s, xtables_chain_protos[i].name) == 0) {
++ if ((xtables_chain_protos[i].name != NULL) &&
++ (strcmp(s, xtables_chain_protos[i].name) == 0)) {
+ proto = xtables_chain_protos[i].num;
+ break;
+ }