Re: [PATCH 04/10] drm/msm: fix NULL-deref on irq uninstall

[Dmitry Baryshkov]

On 06/03/2023 12:07, Johan Hovold wrote:
> In case of early initialisation errors and on platforms that do not use
> the DPU controller, the deinitilisation code can be called with the kms
> pointer set to NULL.
>
> Fixes: f026e431cf86 ("drm/msm: Convert to Linux IRQ interfaces")
> Cc: stable@xxxxxxxxxxxxxxx	# 5.14
> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx>

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>

> ---
>   drivers/gpu/drm/msm/msm_drv.c | 8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 17a59d73fe01..2f2bcdb671d2 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -251,9 +251,11 @@ static int msm_drm_uninit(struct device *dev)
>   		drm_bridge_remove(priv->bridges[i]);
>   	priv->num_bridges = 0;
>   
> -	pm_runtime_get_sync(dev);
> -	msm_irq_uninstall(ddev);
> -	pm_runtime_put_sync(dev);
> +	if (kms) {
> +		pm_runtime_get_sync(dev);
> +		msm_irq_uninstall(ddev);
> +		pm_runtime_put_sync(dev);
> +	}
>   
>   	if (kms && kms->funcs)
>   		kms->funcs->destroy(kms);

--
With best wishes
Dmitry