librenms/html/includes/graphs/location/auth.inc.php

<?php

foreach (dbFetchRows('SELECT * FROM `devices` WHERE `location` = ?', array($vars['id'])) as $device) {
    if ($auth || device_permitted($device_id)) {
        $devices[] = $device;
        $title     = $vars['id'];
        $auth      = true;
    }
}