static int bdrv_file_open(BlockDriverState *bs, const char *filename,
                          QDict **options, int flags, Error **errp)
{
    BlockDriver *drv;
    const char *drvname;
    bool allow_protocol_prefix = false;
    Error *local_err = NULL;
    int ret;

    /* Fetch the file name from the options QDict if necessary */
    if (!filename) {
        filename = qdict_get_try_str(*options, "filename");
    } else if (filename && !qdict_haskey(*options, "filename")) {
        qdict_put(*options, "filename", qstring_from_str(filename));
        allow_protocol_prefix = true;
    } else {
        error_setg(errp, "Can't specify 'file' and 'filename' options at the "
                   "same time");
        ret = -EINVAL;
        goto fail;
    }

    /* Find the right block driver */
    drvname = qdict_get_try_str(*options, "driver");
    if (drvname) {
        drv = bdrv_find_format(drvname);
        if (!drv) {
            error_setg(errp, "Unknown driver '%s'", drvname);
        }
        qdict_del(*options, "driver");
    } else if (filename) {
        drv = bdrv_find_protocol(filename, allow_protocol_prefix);
        if (!drv) {
            error_setg(errp, "Unknown protocol");
        }
    } else {
        error_setg(errp, "Must specify either driver or file");
        drv = NULL;
    }

    if (!drv) {
        /* errp has been set already */
        ret = -ENOENT;
        goto fail;
    }

    /* Parse the filename and open it */
    if (drv->bdrv_parse_filename && filename) {
        drv->bdrv_parse_filename(filename, *options, &local_err);
        if (local_err) {
            error_propagate(errp, local_err);
            ret = -EINVAL;
            goto fail;
        }

        if (!drv->bdrv_needs_filename) {
            qdict_del(*options, "filename");
        } else {
            filename = qdict_get_str(*options, "filename");
        }
    }

    if (!drv->bdrv_file_open) {
        ret = bdrv_open(&bs, filename, NULL, *options, flags, drv, &local_err);
        *options = NULL;
    } else {
        ret = bdrv_open_common(bs, NULL, *options, flags, drv, &local_err);
    }
    if (ret < 0) {
        error_propagate(errp, local_err);
        goto fail;
    }

    bs->growable = 1;
    return 0;

fail:
    return ret;
}

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.