compat_do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user,
		       unsigned int len)
{
	int ret;

	if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
		return -EPERM;

	switch (cmd) {
	case IP6T_SO_SET_REPLACE:
		ret = compat_do_replace(sock_net(sk), user, len);
		break;

	case IP6T_SO_SET_ADD_COUNTERS:
		ret = do_add_counters(sock_net(sk), user, len, 1);
		break;

	default:
		ret = -EINVAL;
	}

	return ret;
}

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