static int atrtr_delete(struct atalk_addr * addr)
{
	struct atalk_route **r = &atalk_routes;
	int retval = 0;
	struct atalk_route *tmp;

	write_lock_bh(&atalk_routes_lock);
	while ((tmp = *r) != NULL) {
		if (tmp->target.s_net == addr->s_net &&
		    (!(tmp->flags&RTF_GATEWAY) ||
		     tmp->target.s_node == addr->s_node)) {
			*r = tmp->next;
			dev_put(tmp->dev);
			kfree(tmp);
			goto out;
		}
		r = &tmp->next;
	}
	retval = -ENOENT;
out:
	write_unlock_bh(&atalk_routes_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.