static void virtio_net_tx_bh(void *opaque)
{
    VirtIONetQueue *q = opaque;
    VirtIONet *n = q->n;
    VirtIODevice *vdev = VIRTIO_DEVICE(n);
    int32_t ret;

    assert(vdev->vm_running);

    q->tx_waiting = 0;

    /* Just in case the driver is not ready on more */
    if (unlikely(!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK))) {
        return;
    }

    ret = virtio_net_flush_tx(q);
    if (ret == -EBUSY) {
        return; /* Notification re-enable handled by tx_complete */
    }

    /* If we flush a full burst of packets, assume there are
     * more coming and immediately reschedule */
    if (ret >= n->tx_burst) {
        qemu_bh_schedule(q->tx_bh);
        q->tx_waiting = 1;
        return;
    }

    /* If less than a full burst, re-enable notification and flush
     * anything that may have come in while we weren't looking.  If
     * we find something, assume the guest is still active and reschedule */
    virtio_queue_set_notification(q->tx_vq, 1);
    if (virtio_net_flush_tx(q) > 0) {
        virtio_queue_set_notification(q->tx_vq, 0);
        qemu_bh_schedule(q->tx_bh);
        q->tx_waiting = 1;
    }
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.