DeliverOneEvent(InternalEvent *event, DeviceIntPtr dev, enum InputLevel level,
                WindowPtr win, Window child, GrabPtr grab)
{
    xEvent *xE = NULL;
    int count = 0;
    int deliveries = 0;
    int rc;

    switch (level) {
    case XI2:
        rc = EventToXI2(event, &xE);
        count = 1;
        break;
    case XI:
        rc = EventToXI(event, &xE, &count);
        break;
    case CORE:
        rc = EventToCore(event, &xE, &count);
        break;
    default:
        rc = BadImplementation;
        break;
    }

    if (rc == Success) {
        deliveries = DeliverEvent(dev, xE, count, win, child, grab);
        free(xE);
    }
    else
        BUG_WARN_MSG(rc != BadMatch,
                     "%s: conversion to level %d failed with rc %d\n",
                     dev->name, level, rc);
    return deliveries;
}

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.