static struct atalk_addr *atalk_find_primary(void)
{
	struct atalk_iface *fiface = NULL;
	struct atalk_addr *retval;
	struct atalk_iface *iface;

	/*
	 * Return a point-to-point interface only if
	 * there is no non-ptp interface available.
	 */
	read_lock_bh(&atalk_interfaces_lock);
	for (iface = atalk_interfaces; iface; iface = iface->next) {
		if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
			fiface = iface;
		if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
			retval = &iface->address;
			goto out;
		}
	}

	if (fiface)
		retval = &fiface->address;
	else if (atalk_interfaces)
		retval = &atalk_interfaces->address;
	else
		retval = NULL;
out:
	read_unlock_bh(&atalk_interfaces_lock);
	return retval;
}

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.