static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid)
{
	struct sock *sock;
	struct netlink_sock *nlk;

	sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid);
	if (!sock)
		return ERR_PTR(-ECONNREFUSED);

	/* Don't bother queuing skb if kernel socket has no input function */
	nlk = nlk_sk(sock);
	if (sock->sk_state == NETLINK_CONNECTED &&
	    nlk->dst_portid != nlk_sk(ssk)->portid) {
		sock_put(sock);
		return ERR_PTR(-ECONNREFUSED);
	}
	return sock;
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.