int rxe_mem_copy(struct rxe_mem *mem, u64 iova, void *addr, int length,
		 enum copy_direction dir, u32 *crcp)
{
	int			err;
	int			bytes;
	u8			*va;
	struct rxe_map		**map;
	struct rxe_phys_buf	*buf;
	int			m;
	int			i;
	size_t			offset;
	u32			crc = crcp ? (*crcp) : 0;

	if (length == 0)
		return 0;

	if (mem->type == RXE_MEM_TYPE_DMA) {
		u8 *src, *dest;

		src  = (dir == to_mem_obj) ?
			addr : ((void *)(uintptr_t)iova);

		dest = (dir == to_mem_obj) ?
			((void *)(uintptr_t)iova) : addr;

		if (crcp)
			*crcp = crc32_le(*crcp, src, length);

		memcpy(dest, src, length);

		return 0;
	}

	WARN_ON(!mem->map);

	err = mem_check_range(mem, iova, length);
	if (err) {
		err = -EFAULT;
		goto err1;
	}

	lookup_iova(mem, iova, &m, &i, &offset);

	map	= mem->map + m;
	buf	= map[0]->buf + i;

	while (length > 0) {
		u8 *src, *dest;

		va	= (u8 *)(uintptr_t)buf->addr + offset;
		src  = (dir == to_mem_obj) ? addr : va;
		dest = (dir == to_mem_obj) ? va : addr;

		bytes	= buf->size - offset;

		if (bytes > length)
			bytes = length;

		if (crcp)
			crc = crc32_le(crc, src, bytes);

		memcpy(dest, src, bytes);

		length	-= bytes;
		addr	+= bytes;

		offset	= 0;
		buf++;
		i++;

		if (i == RXE_BUF_PER_MAP) {
			i = 0;
			map++;
			buf = map[0]->buf;
		}
	}

	if (crcp)
		*crcp = crc;

	return 0;

err1:
	return err;
}

The product 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 occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.