[PATCH] drm/vgem: off by one in vgem_gem_fault()

[Daniel Vetter]

On Tue, Jul 03, 2018 at 03:29:21PM +0300, Dan Carpenter wrote:
> If page_offset is == num_pages then we end up reading beyond the end of
> obj->pages[].
> 
> Fixes: af33a9190d02 ("drm/vgem: Enable dmabuf import interfaces")
> Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
> ---
> Static analysis.  Not tested

Applied, thanks.
-Daniel

> 
> diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c
> index c64a85950c82..0e5620f76ee0 100644
> --- a/drivers/gpu/drm/vgem/vgem_drv.c
> +++ b/drivers/gpu/drm/vgem/vgem_drv.c
> @@ -74,7 +74,7 @@ static vm_fault_t vgem_gem_fault(struct vm_fault *vmf)
>  
>  	num_pages = DIV_ROUND_UP(obj->base.size, PAGE_SIZE);
>  
> -	if (page_offset > num_pages)
> +	if (page_offset >= num_pages)
>  		return VM_FAULT_SIGBUS;
>  
>  	mutex_lock(&obj->pages_lock);

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch