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From: Kees Cook <keescook@chromium.org>
To: Yan Zhao <yan.y.zhao@intel.com>
Cc: alex.williamson@redhat.com, cohuck@redhat.com,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] vfio: checking of validity of user vaddr in vfio_dma_rw
Date: Wed, 8 Apr 2020 09:59:44 -0700	[thread overview]
Message-ID: <202004080959.8C71F8DF7@keescook> (raw)
In-Reply-To: <20200408071121.25645-1-yan.y.zhao@intel.com>

On Wed, Apr 08, 2020 at 03:11:21AM -0400, Yan Zhao wrote:
> instead of calling __copy_to/from_user(), use copy_to_from_user() to
> ensure vaddr range is a valid user address range before accessing them.
> 
> Cc: Kees Cook <keescook@chromium.org>
> 
> Fixes: 8d46c0cca5f4 ("vfio: introduce vfio_dma_rw to read/write a range of IOVAs")
> Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>

Thanks!

Reported-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  drivers/vfio/vfio_iommu_type1.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 3aefcc8e2933..fbc58284b333 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -2345,10 +2345,10 @@ static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu,
>  	vaddr = dma->vaddr + offset;
>  
>  	if (write)
> -		*copied = __copy_to_user((void __user *)vaddr, data,
> +		*copied = copy_to_user((void __user *)vaddr, data,
>  					 count) ? 0 : count;
>  	else
> -		*copied = __copy_from_user(data, (void __user *)vaddr,
> +		*copied = copy_from_user(data, (void __user *)vaddr,
>  					   count) ? 0 : count;
>  	if (kthread)
>  		unuse_mm(mm);
> -- 
> 2.17.1
> 

-- 
Kees Cook

      reply	other threads:[~2020-04-08 16:59 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-08  7:11 [PATCH] vfio: checking of validity of user vaddr in vfio_dma_rw Yan Zhao
2020-04-08 16:59 ` Kees Cook [this message]

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