static BlockAIOCB *iscsi_aio_ioctl(BlockDriverState *bs,
        unsigned long int req, void *buf,
        BlockCompletionFunc *cb, void *opaque)
{
    IscsiLun *iscsilun = bs->opaque;
    struct iscsi_context *iscsi = iscsilun->iscsi;
    struct iscsi_data data;
    IscsiAIOCB *acb;

    acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);

    acb->iscsilun = iscsilun;
    acb->bh          = NULL;
    acb->status      = -EINPROGRESS;
    acb->buf         = NULL;
    acb->ioh         = buf;

    if (req != SG_IO) {
        iscsi_ioctl_handle_emulated(acb, req, buf);
         return &acb->common;
     }
 
    if (acb->ioh->cmd_len > SCSI_CDB_MAX_SIZE) {
        error_report("iSCSI: ioctl error CDB exceeds max size (%d > %d)",
                     acb->ioh->cmd_len, SCSI_CDB_MAX_SIZE);
        qemu_aio_unref(acb);
        return NULL;
    }

     acb->task = malloc(sizeof(struct scsi_task));
     if (acb->task == NULL) {
         error_report("iSCSI: Failed to allocate task for scsi command. %s",
    case SG_DXFER_TO_DEV:
        acb->task->xfer_dir = SCSI_XFER_WRITE;
        break;
    case SG_DXFER_FROM_DEV:
        acb->task->xfer_dir = SCSI_XFER_READ;
        break;
    default:
        acb->task->xfer_dir = SCSI_XFER_NONE;
        break;
    }

    acb->task->cdb_size = acb->ioh->cmd_len;
    memcpy(&acb->task->cdb[0], acb->ioh->cmdp, acb->ioh->cmd_len);
    acb->task->expxferlen = acb->ioh->dxfer_len;

    data.size = 0;
    if (acb->task->xfer_dir == SCSI_XFER_WRITE) {
        if (acb->ioh->iovec_count == 0) {
            data.data = acb->ioh->dxferp;
            data.size = acb->ioh->dxfer_len;
        } else {
            scsi_task_set_iov_out(acb->task,
                                 (struct scsi_iovec *) acb->ioh->dxferp,
                                 acb->ioh->iovec_count);
        }
    }

    if (iscsi_scsi_command_async(iscsi, iscsilun->lun, acb->task,
                                 iscsi_aio_ioctl_cb,
                                 (data.size > 0) ? &data : NULL,
                                 acb) != 0) {
        scsi_free_scsi_task(acb->task);
        qemu_aio_unref(acb);
        return NULL;
    }

    /* tell libiscsi to read straight into the buffer we got from ioctl */
    if (acb->task->xfer_dir == SCSI_XFER_READ) {
        if (acb->ioh->iovec_count == 0) {
            scsi_task_add_data_in_buffer(acb->task,
                                         acb->ioh->dxfer_len,
                                         acb->ioh->dxferp);
        } else {
            scsi_task_set_iov_in(acb->task,
                                 (struct scsi_iovec *) acb->ioh->dxferp,
                                 acb->ioh->iovec_count);
        }
    }

    iscsi_set_events(iscsilun);

    return &acb->common;
}

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.