The patch below does not apply to the 4.4-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;