From c660133c339f9ab684fdf568c0d51b9ae5e86002 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 16 Apr 2019 14:07:25 +0300 Subject: 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 Reviewed-by: Haggai Eran Signed-off-by: Leon Romanovsky --- drivers/infiniband/hw/mlx5/main.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/infiniband') diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c index 241d9ead79eb..12a75dfc992b 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) -- cgit v1.2.3