Hi Paul,

Thank you for the patch.

On Sun, Jan 17, 2021 at 11:26:45AM +0000, Paul Cercueil wrote:
> Since the encoders have been devm-allocated, they will be freed way
> before drm_mode_config_cleanup() is called. To avoid use-after-free
> conditions, we then must ensure that drm_encoder_cleanup() is called
> before the encoders are freed.

How about allocating the encoder with drmm_encoder_alloc() instead ?

> Fixes: c369cb27c267 ("drm/ingenic: Support multiple panels/bridges")
> Cc: <sta...@vger.kernel.org> # 5.8+
> Signed-off-by: Paul Cercueil <p...@crapouillou.net>
> ---
>  drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c 
> b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
> index 368bfef8b340..d23a3292a0e0 100644
> --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
> +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
> @@ -803,6 +803,11 @@ static void __maybe_unused ingenic_drm_release_rmem(void 
> *d)
>       of_reserved_mem_device_release(d);
>  }
>  
> +static void ingenic_drm_encoder_cleanup(void *encoder)
> +{
> +     drm_encoder_cleanup(encoder);
> +}
> +
>  static int ingenic_drm_bind(struct device *dev, bool has_components)
>  {
>       struct platform_device *pdev = to_platform_device(dev);
> @@ -1011,6 +1016,11 @@ static int ingenic_drm_bind(struct device *dev, bool 
> has_components)
>                       return ret;
>               }
>  
> +             ret = devm_add_action_or_reset(dev, ingenic_drm_encoder_cleanup,
> +                                            encoder);
> +             if (ret)
> +                     return ret;
> +
>               ret = drm_bridge_attach(encoder, bridge, NULL, 0);
>               if (ret) {
>                       dev_err(dev, "Unable to attach bridge\n");

-- 
Regards,

Laurent Pinchart
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