[PATCH] drm: Make sure that encoder_type for drm_encoder_init() is in the list

[Daniel Vetter]

On Fri, Jun 29, 2018 at 03:47:43PM -0600, Jordan Crouse wrote:
> If a encoder name isn't specified for drm_encoder_init() it will try
> to construct one based on the incoming encoder_type identifier. If the
> caller passes an invalid encoder_type value the lookup could walk right
> past the end of the table.
> 
> [v2: Use a WARN() at the top of the function as suggested by Daniel
>  Vetter]
> 
> Signed-off-by: Jordan Crouse <jcrouse at codeaurora.org>

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

Aside: Want drm-misc commit rights so you can push patches like these
yourself?

Might also be useful in case the group maintainership thing with msm
happens, just as prep.
-Daniel

> ---
>  drivers/gpu/drm/drm_encoder.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_encoder.c b/drivers/gpu/drm/drm_encoder.c
> index 273e1c59c54a..6228c2cee5f0 100644
> --- a/drivers/gpu/drm/drm_encoder.c
> +++ b/drivers/gpu/drm/drm_encoder.c
> @@ -114,6 +114,10 @@ int drm_encoder_init(struct drm_device *dev,
>  	if (WARN_ON(dev->mode_config.num_encoder >= 32))
>  		return -EINVAL;
>  
> +	/* Make sure that the requested encoder type is in the list */
> +	if (WARN_ON(encoder_type >= ARRAY_SIZE(drm_encoder_enum_list)))
> +		return -EINVAL;
> +
>  	ret = drm_mode_object_add(dev, &encoder->base, DRM_MODE_OBJECT_ENCODER);
>  	if (ret)
>  		return ret;
> -- 
> 2.17.1
> 

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