IB/mlx5: Move MRs to a kernel PD when freeing them to the MR cache

commit 9ec4483a3f0f71a228a5933bc040441322bfb090 upstream.

Fix unreg_umr to move the MR to a kernel owned PD (i.e. the UMR PD) which
can't be accessed by userspace.

This ensures that nothing can continue to access the MR once it has been
placed in the kernels cache for reuse.

MRs in the cache continue to have their HW state, including DMA tables,
present. Even though the MR has been invalidated, changing the PD provides
an additional layer of protection against use of the MR.

Link: https://lore.kernel.org/r/20190723065733.4899-5-leon@kernel.org
Cc: <stable@vger.kernel.org> # 3.10
Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Reviewed-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
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 903f4c1028fccdd330b086b4920a1bed9345ac12..cfddca850cb4d385ed05242e73649e48f1223bb1 100644 (file)
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -1305,8 +1305,10 @@ static int unreg_umr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
        if (mdev->state == MLX5_DEVICE_STATE_INTERNAL_ERROR)
                return 0;
 
-       umrwr.wr.send_flags = MLX5_IB_SEND_UMR_DISABLE_MR;
+       umrwr.wr.send_flags = MLX5_IB_SEND_UMR_DISABLE_MR |
+                             MLX5_IB_SEND_UMR_UPDATE_PD_ACCESS;
        umrwr.wr.opcode = MLX5_IB_WR_UMR;
+       umrwr.pd = dev->umrc.pd;
        umrwr.mkey = mr->mmkey.key;
        umrwr.ignore_free_state = 1;