static int bnep_rx_control(struct bnep_session *s, void *data, int len)
{
	u8  cmd = *(u8 *)data;
	int err = 0;

	data++;
	len--;

	switch (cmd) {
	case BNEP_CMD_NOT_UNDERSTOOD:
	case BNEP_SETUP_CONN_RSP:
	case BNEP_FILTER_NET_TYPE_RSP:
	case BNEP_FILTER_MULTI_ADDR_RSP:
		/* Ignore these for now */
		break;

	case BNEP_FILTER_NET_TYPE_SET:
		err = bnep_ctrl_set_netfilter(s, data, len);
		break;

	case BNEP_FILTER_MULTI_ADDR_SET:
		err = bnep_ctrl_set_mcfilter(s, data, len);
		break;

	case BNEP_SETUP_CONN_REQ:
		err = bnep_send_rsp(s, BNEP_SETUP_CONN_RSP, BNEP_CONN_NOT_ALLOWED);
		break;

	default: {
			u8 pkt[3];
			pkt[0] = BNEP_CONTROL;
			pkt[1] = BNEP_CMD_NOT_UNDERSTOOD;
			pkt[2] = cmd;
			bnep_send(s, pkt, sizeof(pkt));
		}
		break;
	}

	return err;
}

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.