int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id)
{
    int i, ret;
    int32_t config_len;
    uint32_t num;
    uint32_t features;
    BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
    VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);

    /*
     * We poison the endianness to ensure it does not get used before
     * subsections have been loaded.
     */
    vdev->device_endian = VIRTIO_DEVICE_ENDIAN_UNKNOWN;

    if (k->load_config) {
        ret = k->load_config(qbus->parent, f);
        if (ret)
            return ret;
    }

    qemu_get_8s(f, &vdev->status);
    qemu_get_8s(f, &vdev->isr);
    qemu_get_be16s(f, &vdev->queue_sel);
    if (vdev->queue_sel >= VIRTIO_QUEUE_MAX) {
        return -1;
    }
    qemu_get_be32s(f, &features);

    /*
     * Temporarily set guest_features low bits - needed by
     * virtio net load code testing for VIRTIO_NET_F_CTRL_GUEST_OFFLOADS
     * VIRTIO_NET_F_GUEST_ANNOUNCE and VIRTIO_NET_F_CTRL_VQ.
     *
     * Note: devices should always test host features in future - don't create
     * new dependencies like this.
     */
    vdev->guest_features = features;

    config_len = qemu_get_be32(f);

    /*
     * There are cases where the incoming config can be bigger or smaller
     * than what we have; so load what we have space for, and skip
     * any excess that's in the stream.
     */
    qemu_get_buffer(f, vdev->config, MIN(config_len, vdev->config_len));

    while (config_len > vdev->config_len) {
        qemu_get_byte(f);
        config_len--;
    }

    num = qemu_get_be32(f);

    if (num > VIRTIO_QUEUE_MAX) {
        error_report("Invalid number of virtqueues: 0x%x", num);
        return -1;
    }

    for (i = 0; i < num; i++) {
        vdev->vq[i].vring.num = qemu_get_be32(f);
        if (k->has_variable_vring_alignment) {
            vdev->vq[i].vring.align = qemu_get_be32(f);
        }
        vdev->vq[i].vring.desc = qemu_get_be64(f);
        qemu_get_be16s(f, &vdev->vq[i].last_avail_idx);
        vdev->vq[i].signalled_used_valid = false;
        vdev->vq[i].notification = true;

        if (vdev->vq[i].vring.desc) {
            /* XXX virtio-1 devices */
            virtio_queue_update_rings(vdev, i);
        } else if (vdev->vq[i].last_avail_idx) {
            error_report("VQ %d address 0x0 "
                         "inconsistent with Host index 0x%x",
                         i, vdev->vq[i].last_avail_idx);
                return -1;
	}
        if (k->load_queue) {
            ret = k->load_queue(qbus->parent, i, f);
            if (ret)
                return ret;
        }
    }

    virtio_notify_vector(vdev, VIRTIO_NO_VECTOR);

    if (vdc->load != NULL) {
        ret = vdc->load(vdev, f, version_id);
        if (ret) {
            return ret;
        }
    }

    /* Subsections */
    ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1);
    if (ret) {
        return ret;
    }

    if (vdev->device_endian == VIRTIO_DEVICE_ENDIAN_UNKNOWN) {
        vdev->device_endian = virtio_default_endian();
    }

    if (virtio_64bit_features_needed(vdev)) {
        /*
         * Subsection load filled vdev->guest_features.  Run them
         * through virtio_set_features to sanity-check them against
         * host_features.
         */
        uint64_t features64 = vdev->guest_features;
        if (virtio_set_features_nocheck(vdev, features64) < 0) {
            error_report("Features 0x%" PRIx64 " unsupported. "
                         "Allowed features: 0x%" PRIx64,
                         features64, vdev->host_features);
            return -1;
        }
    } else {
        if (virtio_set_features_nocheck(vdev, features) < 0) {
            error_report("Features 0x%x unsupported. "
                         "Allowed features: 0x%" PRIx64,
                         features, vdev->host_features);
            return -1;
        }
    }

    for (i = 0; i < num; i++) {
        if (vdev->vq[i].vring.desc) {
            uint16_t nheads;
            nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx;
            /* Check it isn't doing strange things with descriptor numbers. */
            if (nheads > vdev->vq[i].vring.num) {
                error_report("VQ %d size 0x%x Guest index 0x%x "
                             "inconsistent with Host index 0x%x: delta 0x%x",
                             i, vdev->vq[i].vring.num,
                             vring_avail_idx(&vdev->vq[i]),
                             vdev->vq[i].last_avail_idx, nheads);
                return -1;
            }
            vdev->vq[i].used_idx = vring_used_idx(&vdev->vq[i]);
            vdev->vq[i].shadow_avail_idx = vring_avail_idx(&vdev->vq[i]);
        }
    }

    return 0;
}

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.