Re: [PATCH] drm/vmwgfx: NULL pointer dereference from vmw_cmd_dx_view_define()

[Thomas Hellstrom <thellstrom@vmware.com>]

On Sat, 2019-05-11 at 18:01 +1200, Murray McAllister wrote:
> If SVGA_3D_CMD_DX_DEFINE_RENDERTARGET_VIEW is called with a surface
> ID of SVGA3D_INVALID_ID, the srf struct will remain NULL after
> vmw_cmd_res_check(), leading to a null pointer dereference in
> vmw_view_add().
> 
> Signed-off-by: Murray McAllister <murray.mcallister@gmail.com>

Thanks, I'll add this to the next -fixes pull.
Thomas


> ---
>  drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
> b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
> index 2ff7ba04d8c8..447afd086206 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
> @@ -2414,6 +2414,10 @@ static int vmw_cmd_dx_view_define(struct
> vmw_private *dev_priv,
>  		return -EINVAL;
>  
>  	cmd = container_of(header, typeof(*cmd), header);
> +	if (unlikely(cmd->sid == SVGA3D_INVALID_ID)) {
> +		DRM_ERROR("Invalid surface id.\n");
> +		return -EINVAL;
> +	}
>  	ret = vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
>  				VMW_RES_DIRTY_NONE,
> user_surface_converter,
>  				&cmd->sid, &srf);