mtree_bid(struct archive_read *a, int best_bid)
{
	const char *signature = "#mtree";
	const char *p;

	(void)best_bid; /* UNUSED */

	/* Now let's look at the actual header and see if it matches. */
	p = __archive_read_ahead(a, strlen(signature), NULL);
	if (p == NULL)
		return (-1);

	if (memcmp(p, signature, strlen(signature)) == 0)
		return (8 * (int)strlen(signature));

	/*
	 * There is not a mtree signature. Let's try to detect mtree format.
	 */
	return (detect_form(a, NULL));
}

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.