GetEventFilter(DeviceIntPtr dev, xEvent *event)
{
    int evtype = 0;

    if (event->u.u.type != GenericEvent)
        return event_get_filter_from_type(dev, event->u.u.type);
    else if ((evtype = xi2_get_type(event)))
        return event_get_filter_from_xi2type(evtype);
    ErrorF("[dix] Unknown event type %d. No filter\n", event->u.u.type);
    return 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.