static int __init ip_tables_init(void)
{
	int ret;

	ret = register_pernet_subsys(&ip_tables_net_ops);
	if (ret < 0)
		goto err1;

	/* No one else will be downing sem now, so we won't sleep */
	ret = xt_register_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
	if (ret < 0)
		goto err2;
	ret = xt_register_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
	if (ret < 0)
		goto err4;

	/* Register setsockopt */
	ret = nf_register_sockopt(&ipt_sockopts);
	if (ret < 0)
		goto err5;

	return 0;

err5:
	xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
err4:
	xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
err2:
	unregister_pernet_subsys(&ip_tables_net_ops);
err1:
	return ret;
}

The product dereferences a pointer that it expects to be valid but is NULL.