On Tue, May 19, 2020 at 3:32 PM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> The problem is that "req->sg_cnt" is an unsigned int so if "nr" is
> negative, it gets type promoted to a high positive value and the
> condition is false. This patch fixes it by handling negatives separately.
>
> Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Thanks Dan,
Reviewed-by: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxx>
> ---
> v2: propagate the correct error code instead of returning -EINVAL
>
> drivers/infiniband/ulp/rtrs/rtrs-clt.c | 7 +++----
> drivers/infiniband/ulp/rtrs/rtrs-srv.c | 2 +-
> 2 files changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> index 468fdd0d8713..17f99f0962d0 100644
> --- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> @@ -1047,11 +1047,10 @@ static int rtrs_map_sg_fr(struct rtrs_clt_io_req *req, size_t count)
>
> /* Align the MR to a 4K page size to match the block virt boundary */
> nr = ib_map_mr_sg(req->mr, req->sglist, count, NULL, SZ_4K);
> - if (unlikely(nr < req->sg_cnt)) {
> - if (nr < 0)
> - return nr;
> + if (nr < 0)
> + return nr;
> + if (unlikely(nr < req->sg_cnt))
> return -EINVAL;
> - }
> ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey));
>
> return nr;
> diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv.c b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
> index ba8ab33b94a2..eefd149ce7a4 100644
> --- a/drivers/infiniband/ulp/rtrs/rtrs-srv.c
> +++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
> @@ -649,7 +649,7 @@ static int map_cont_bufs(struct rtrs_srv_sess *sess)
> }
> nr = ib_map_mr_sg(mr, sgt->sgl, sgt->nents,
> NULL, max_chunk_size);
> - if (nr < sgt->nents) {
> + if (nr < 0 || nr < sgt->nents) {
> err = nr < 0 ? nr : -EINVAL;
> goto dereg_mr;
> }
> --
> 2.26.2
