static int llcp_sock_connect(struct socket *sock, struct sockaddr *_addr,
			     int len, int flags)
{
	struct sock *sk = sock->sk;
	struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
	struct sockaddr_nfc_llcp *addr = (struct sockaddr_nfc_llcp *)_addr;
	struct nfc_dev *dev;
	struct nfc_llcp_local *local;
	int ret = 0;

	pr_debug("sock %p sk %p flags 0x%x\n", sock, sk, flags);

	if (!addr || len < sizeof(struct sockaddr_nfc) ||
	    addr->sa_family != AF_NFC)
		return -EINVAL;

	if (addr->service_name_len == 0 && addr->dsap == 0)
		return -EINVAL;

	pr_debug("addr dev_idx=%u target_idx=%u protocol=%u\n", addr->dev_idx,
		 addr->target_idx, addr->nfc_protocol);

	lock_sock(sk);

	if (sk->sk_state == LLCP_CONNECTED) {
		ret = -EISCONN;
		goto error;
	}

	dev = nfc_get_device(addr->dev_idx);
	if (dev == NULL) {
		ret = -ENODEV;
		goto error;
	}

	local = nfc_llcp_find_local(dev);
	if (local == NULL) {
		ret = -ENODEV;
		goto put_dev;
	}

	device_lock(&dev->dev);
	if (dev->dep_link_up == false) {
		ret = -ENOLINK;
		device_unlock(&dev->dev);
		goto put_dev;
	}
	device_unlock(&dev->dev);

	if (local->rf_mode == NFC_RF_INITIATOR &&
	    addr->target_idx != local->target_idx) {
		ret = -ENOLINK;
		goto put_dev;
	}

	llcp_sock->dev = dev;
	llcp_sock->local = nfc_llcp_local_get(local);
	llcp_sock->remote_miu = llcp_sock->local->remote_miu;
	llcp_sock->ssap = nfc_llcp_get_local_ssap(local);
	if (llcp_sock->ssap == LLCP_SAP_MAX) {
		ret = -ENOMEM;
		goto put_dev;
	}

	llcp_sock->reserved_ssap = llcp_sock->ssap;

	if (addr->service_name_len == 0)
		llcp_sock->dsap = addr->dsap;
	else
		llcp_sock->dsap = LLCP_SAP_SDP;
	llcp_sock->nfc_protocol = addr->nfc_protocol;
	llcp_sock->service_name_len = min_t(unsigned int,
					    addr->service_name_len,
					    NFC_LLCP_MAX_SERVICE_NAME);
	llcp_sock->service_name = kmemdup(addr->service_name,
					  llcp_sock->service_name_len,
					  GFP_KERNEL);

	nfc_llcp_sock_link(&local->connecting_sockets, sk);

	ret = nfc_llcp_send_connect(llcp_sock);
	if (ret)
		goto sock_unlink;

	sk->sk_state = LLCP_CONNECTING;

	ret = sock_wait_state(sk, LLCP_CONNECTED,
			      sock_sndtimeo(sk, flags & O_NONBLOCK));
	if (ret && ret != -EINPROGRESS)
		goto sock_unlink;

	release_sock(sk);

	return ret;

sock_unlink:
	nfc_llcp_put_ssap(local, llcp_sock->ssap);

	nfc_llcp_sock_unlink(&local->connecting_sockets, sk);

put_dev:
	nfc_put_device(dev);

error:
	release_sock(sk);
	return ret;
}

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.