static int cmp_map_id(const void *k, const void *e)
{
	u32 first, last, id2;
	const struct idmap_key *key = k;
	const struct uid_gid_extent *el = e;

	id2 = key->id + key->count - 1;

	/* handle map_id_{down,up}() */
	if (key->map_up)
		first = el->lower_first;
	else
		first = el->first;

	last = first + el->count - 1;

	if (key->id >= first && key->id <= last &&
	    (id2 >= first && id2 <= last))
		return 0;

	if (key->id < first || id2 < first)
		return -1;

	return 1;
}

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.