cdf_read_sector(const cdf_info_t *info, void *buf, size_t offs, size_t len,
    const cdf_header_t *h, cdf_secid_t id)
{
	size_t ss = CDF_SEC_SIZE(h);
	size_t pos = CDF_SEC_POS(h, id);
	assert(ss == len);
	return cdf_read(info, (off_t)pos, ((char *)buf) + offs, len);
}
The software performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer.