int rxe_mem_init_user(struct rxe_dev *rxe, struct rxe_pd *pd, u64 start,
		      u64 length, u64 iova, int access, struct ib_udata *udata,
		      struct rxe_mem *mem)
{
	int			entry;
	struct rxe_map		**map;
	struct rxe_phys_buf	*buf = NULL;
	struct ib_umem		*umem;
	struct scatterlist	*sg;
	int			num_buf;
	void			*vaddr;
	int err;

	umem = ib_umem_get(pd->ibpd.uobject->context, start, length, access, 0);
	if (IS_ERR(umem)) {
		pr_warn("err %d from rxe_umem_get\n",
			(int)PTR_ERR(umem));
		err = -EINVAL;
		goto err1;
	}

	mem->umem = umem;
	num_buf = umem->nmap;

	rxe_mem_init(access, mem);

	err = rxe_mem_alloc(rxe, mem, num_buf);
	if (err) {
		pr_warn("err %d from rxe_mem_alloc\n", err);
		ib_umem_release(umem);
		goto err1;
	}

	WARN_ON(!is_power_of_2(umem->page_size));

	mem->page_shift		= ilog2(umem->page_size);
	mem->page_mask		= umem->page_size - 1;

	num_buf			= 0;
	map			= mem->map;
	if (length > 0) {
		buf = map[0]->buf;

		for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
			vaddr = page_address(sg_page(sg));
			if (!vaddr) {
				pr_warn("null vaddr\n");
				err = -ENOMEM;
				goto err1;
			}

			buf->addr = (uintptr_t)vaddr;
			buf->size = umem->page_size;
			num_buf++;
			buf++;

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

	mem->pd			= pd;
	mem->umem		= umem;
	mem->access		= access;
	mem->length		= length;
	mem->iova		= iova;
	mem->va			= start;
	mem->offset		= ib_umem_offset(umem);
	mem->state		= RXE_MEM_STATE_VALID;
	mem->type		= RXE_MEM_TYPE_MR;

	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.