From c660133c339f9ab684fdf568c0d51b9ae5e86002 Mon Sep 17 00:00:00 2001
From: Jason Gunthorpe <jgg@mellanox.com>
Date: Tue, 16 Apr 2019 14:07:25 +0300
Subject: [PATCH] RDMA/mlx5: Do not allow the user to write to the clock page
The intent of this VMA was to be read-only from user space, but the
VM_MAYWRITE masking was missed, so mprotect could make it writable.
Cc: stable@vger.kernel.org
Fixes: 5c99eaecb1fc ("IB/mlx5: Mmap the HCA's clock info to user-space")
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
---
drivers/infiniband/hw/mlx5/main.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index 241d9ead79eb1..12a75dfc992b6 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -2068,6 +2068,7 @@ static int mlx5_ib_mmap_clock_info_page(struct mlx5_ib_dev *dev,
if (vma->vm_flags & VM_WRITE)
return -EPERM;
+ vma->vm_flags &= ~VM_MAYWRITE;
if (!dev->mdev->clock_info_page)
return -EOPNOTSUPP;
@@ -2233,6 +2234,7 @@ static int mlx5_ib_mmap(struct ib_ucontext *ibcontext, struct vm_area_struct *vm
if (vma->vm_flags & VM_WRITE)
return -EPERM;
+ vma->vm_flags &= ~VM_MAYWRITE;
/* Don't expose to user-space information it shouldn't have */
if (PAGE_SIZE > 4096)
--
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