static int xen_vbd_translate(struct phys_req *req, struct xen_blkif *blkif,
			     int operation)
{
	struct xen_vbd *vbd = &blkif->vbd;
	int rc = -EACCES;

	if ((operation != READ) && vbd->readonly)
		goto out;

	if (likely(req->nr_sects)) {
		blkif_sector_t end = req->sector_number + req->nr_sects;

		if (unlikely(end < req->sector_number))
			goto out;
		if (unlikely(end > vbd_sz(vbd)))
			goto out;
	}

	req->dev  = vbd->pdevice;
	req->bdev = vbd->bdev;
	rc = 0;

 out:
	return rc;
}

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.