From 1af34bf97eca3624b5f2ec786527c8609e1a68b8 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 16 Apr 2019 14:07:25 +0300 Subject: [PATCH] RDMA/mlx5: Do not allow the user to write to the clock page commit c660133c339f9ab684fdf568c0d51b9ae5e86002 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- 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 50be240df331..8cc4da62f050 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -2014,6 +2014,7 @@ 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; @@ -2197,6 +2198,7 @@ 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) -- GitLab