IB/mlx5: Fix incorrect size of klms in the memory region

commit da343b6d90e11132f1e917d865d88ee35d6e6d00 upstream.

The value of mr->ndescs greater than mr->max_descs is set in the
function mlx5_ib_sg_to_klms() if sg_nents is greater than
mr->max_descs. This is an invalid value and it causes the
following error when registering mr:

mlx5_0:dump_cqe:276:(pid 193): dump error cqe
00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000030: 00 00 00 00 0f 00 78 06 25 00 00 8b 08 1e 8f d3

Cc: <stable@vger.kernel.org> # 4.5
Fixes: b005d3164713 ("mlx5: Add arbitrary sg list support")
Signed-off-by: Sergey Gorenko <sergeygo@mellanox.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index 231b043..000937f 100644 (file)
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -1813,7 +1813,6 @@ mlx5_ib_sg_to_klms(struct mlx5_ib_mr *mr,
 
        mr->ibmr.iova = sg_dma_address(sg) + sg_offset;
        mr->ibmr.length = 0;
-       mr->ndescs = sg_nents;
 
        for_each_sg(sgl, sg, sg_nents, i) {
                if (unlikely(i >= mr->max_descs))
@@ -1825,6 +1824,7 @@ mlx5_ib_sg_to_klms(struct mlx5_ib_mr *mr,
 
                sg_offset = 0;
        }
+       mr->ndescs = i;
 
        if (sg_offset_p)
                *sg_offset_p = sg_offset;