FAILED: patch "[PATCH] IB/mlx5: Move MRs to a kernel PD when freeing them to the MR" failed to apply to 4.9-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 9ec4483a3f0f71a228a5933bc040441322bfb090 Mon Sep 17 00:00:00 2001
From: Yishai Hadas <yishaih@mellanox.com>
Date: Tue, 23 Jul 2019 09:57:27 +0300
Subject: [PATCH] IB/mlx5: Move MRs to a kernel PD when freeing them to the MR
 cache

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>

diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index b83361aebf28..7274a9b9df58 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -1375,8 +1375,10 @@ 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;