jpc_streamlist_t *jpc_ppmstabtostreams(jpc_ppxstab_t *tab)
{
	jpc_streamlist_t *streams;
	uchar *dataptr;
	uint_fast32_t datacnt;
	uint_fast32_t tpcnt;
	jpc_ppxstabent_t *ent;
	int entno;
	jas_stream_t *stream;
	int n;

	if (!(streams = jpc_streamlist_create())) {
		goto error;
	}

	if (!tab->numents) {
		return streams;
	}

	entno = 0;
	ent = tab->ents[entno];
	dataptr = ent->data;
	datacnt = ent->len;
	for (;;) {

		/* Get the length of the packet header data for the current
		  tile-part. */
		if (datacnt < 4) {
			goto error;
		}
		if (!(stream = jas_stream_memopen(0, 0))) {
			goto error;
		}
		if (jpc_streamlist_insert(streams, jpc_streamlist_numstreams(streams),
		  stream)) {
			goto error;
		}
		tpcnt = (dataptr[0] << 24) | (dataptr[1] << 16) | (dataptr[2] << 8)
		  | dataptr[3];
		datacnt -= 4;
		dataptr += 4;

		/* Get the packet header data for the current tile-part. */
		while (tpcnt) {
			if (!datacnt) {
				if (++entno >= tab->numents) {
					goto error;
				}
				ent = tab->ents[entno];
				dataptr = ent->data;
				datacnt = ent->len;
			}
			n = JAS_MIN(tpcnt, datacnt);
			if (jas_stream_write(stream, dataptr, n) != n) {
				goto error;
			}
			tpcnt -= n;
			dataptr += n;
			datacnt -= n;
		}
		jas_stream_rewind(stream);
		if (!datacnt) {
			if (++entno >= tab->numents) {
				break;
			}
			ent = tab->ents[entno];
			dataptr = ent->data;
			datacnt = ent->len;
		}
	}

	return streams;

error:
	if (streams) {
		jpc_streamlist_destroy(streams);
	}
	return 0;
}
The software performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control.