static void virtio_net_device_realize(DeviceState *dev, Error **errp)
{
    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
    VirtIONet *n = VIRTIO_NET(dev);
    NetClientState *nc;
    int i;

    virtio_init(vdev, "virtio-net", VIRTIO_ID_NET, n->config_size);

    n->max_queues = MAX(n->nic_conf.queues, 1);
    n->vqs = g_malloc0(sizeof(VirtIONetQueue) * n->max_queues);
    n->vqs[0].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx);
    n->curr_queues = 1;
    n->vqs[0].n = n;
    n->tx_timeout = n->net_conf.txtimer;

    if (n->net_conf.tx && strcmp(n->net_conf.tx, "timer")
                       && strcmp(n->net_conf.tx, "bh")) {
        error_report("virtio-net: "
                     "Unknown option tx=%s, valid options: \"timer\" \"bh\"",
                     n->net_conf.tx);
        error_report("Defaulting to \"bh\"");
    }

    if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
        n->vqs[0].tx_vq = virtio_add_queue(vdev, 256,
                                           virtio_net_handle_tx_timer);
        n->vqs[0].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, virtio_net_tx_timer,
                                               &n->vqs[0]);
    } else {
        n->vqs[0].tx_vq = virtio_add_queue(vdev, 256,
                                           virtio_net_handle_tx_bh);
        n->vqs[0].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[0]);
    }
    n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
    qemu_macaddr_default_if_unset(&n->nic_conf.macaddr);
    memcpy(&n->mac[0], &n->nic_conf.macaddr, sizeof(n->mac));
    n->status = VIRTIO_NET_S_LINK_UP;

    if (n->netclient_type) {
        /*
         * Happen when virtio_net_set_netclient_name has been called.
         */
        n->nic = qemu_new_nic(&net_virtio_info, &n->nic_conf,
                              n->netclient_type, n->netclient_name, n);
    } else {
        n->nic = qemu_new_nic(&net_virtio_info, &n->nic_conf,
                              object_get_typename(OBJECT(dev)), dev->id, n);
    }

    peer_test_vnet_hdr(n);
    if (peer_has_vnet_hdr(n)) {
        for (i = 0; i < n->max_queues; i++) {
            qemu_using_vnet_hdr(qemu_get_subqueue(n->nic, i)->peer, true);
        }
        n->host_hdr_len = sizeof(struct virtio_net_hdr);
    } else {
        n->host_hdr_len = 0;
    }

    qemu_format_nic_info_str(qemu_get_queue(n->nic), n->nic_conf.macaddr.a);

    n->vqs[0].tx_waiting = 0;
    n->tx_burst = n->net_conf.txburst;
    virtio_net_set_mrg_rx_bufs(n, 0);
    n->promisc = 1; /* for compatibility */

    n->mac_table.macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);

    n->vlans = g_malloc0(MAX_VLAN >> 3);

    nc = qemu_get_queue(n->nic);
    nc->rxfilter_notify_enabled = 1;

    n->qdev = dev;
    register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION,
                    virtio_net_save, virtio_net_load, n);

    add_boot_device_path(n->nic_conf.bootindex, dev, "/ethernet-phy@0");
}

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.