Re: [PATCH 2/4] vfio: use __aligned_u64 in struct vfio_device_gfx_plane_info

[Jason Gunthorpe]

On Wed, Aug 09, 2023 at 05:02:46PM -0400, Stefan Hajnoczi wrote:
> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
> index de675d799c7d..ffab3536dc8a 100644
> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
> @@ -1382,7 +1382,7 @@ static long intel_vgpu_ioctl(struct vfio_device *vfio_dev, unsigned int cmd,
>  		intel_gvt_reset_vgpu(vgpu);
>  		return 0;
>  	} else if (cmd == VFIO_DEVICE_QUERY_GFX_PLANE) {
> -		struct vfio_device_gfx_plane_info dmabuf;
> +		struct vfio_device_gfx_plane_info dmabuf = {};
>  		int ret = 0;
>  
>  		minsz = offsetofend(struct vfio_device_gfx_plane_info,
> @@ -1392,6 +1392,8 @@ static long intel_vgpu_ioctl(struct vfio_device *vfio_dev, unsigned int cmd,
>  		if (dmabuf.argsz < minsz)
>  			return -EINVAL;
>  
> +		minsz = min(minsz, sizeof(dmabuf));
> +

Huh?

 minsz = min(sizeof(dmabuf), dmabuf.argsz)

>  		ret = intel_vgpu_query_plane(vgpu, &dmabuf);
>  		if (ret != 0)
>  			return ret;
> diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
> index c6c6b5d26670..ee42a780041f 100644
> --- a/samples/vfio-mdev/mbochs.c
> +++ b/samples/vfio-mdev/mbochs.c
> @@ -1262,7 +1262,7 @@ static long mbochs_ioctl(struct vfio_device *vdev, unsigned int cmd,
>  
>  	case VFIO_DEVICE_QUERY_GFX_PLANE:
>  	{
> -		struct vfio_device_gfx_plane_info plane;
> +		struct vfio_device_gfx_plane_info plane = {};
>  
>  		minsz = offsetofend(struct vfio_device_gfx_plane_info,
>  				    region_index);
> @@ -1273,11 +1273,13 @@ static long mbochs_ioctl(struct vfio_device *vdev, unsigned int cmd,
>  		if (plane.argsz < minsz)
>  			return -EINVAL;
>  
> +		outsz = min_t(unsigned long, plane.argsz, sizeof(plane));
> +

This one is right

Jason