Re: [PATCH v3] drm/nouveau: Fix memory leaks in debugfs and hwmon init error paths

[lyude]

Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx>

Will push to drm-misc-fixes in a moment

On Fri, 2026-10-09 at 19:51 +0800, liupeng wrote:
> In nouveau_debugfs_init(), if nvif_object_ctor() fails, the
> previously
> allocated drm->debugfs is leaked because the function returns the
> error code directly.
> 
> In nouveau_hwmon_init(), if hwmon_device_register_with_info() fails,
> the allocated hwmon structure is leaked because the function returns
> the error code directly.
> 
> Fix both by freeing the allocated memory and clearing the pointer on
> the error paths.
> 
> Fixes: b126a200e9db ("drm/nouveau/debugfs: we need a ctrl object for
> debugfs")
> Fixes: b9ed919f1c8f ("drm/nouveau/drm/pm: remove everything except
> the hwmon interfaces to THERM")
> Cc: stable@xxxxxxxxxxxxxxx
> Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx>
> Signed-off-by: liupeng <liupeng01@xxxxxxxxxx>
> ---
> Changes in v3:
> - Drop the extra return in nouveau_debugfs_init() as suggested by
> Lyude.
> - Add Reviewed-by tag.
> 
>  drivers/gpu/drm/nouveau/nouveau_debugfs.c | 14 +++++++++++---
>  drivers/gpu/drm/nouveau/nouveau_hwmon.c   |  2 ++
>  2 files changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nouveau_debugfs.c
> b/drivers/gpu/drm/nouveau/nouveau_debugfs.c
> index 47d5579c568d..338421e52f69 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_debugfs.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_debugfs.c
> @@ -295,13 +295,21 @@ nouveau_drm_debugfs_init(struct drm_minor
> *minor)
>  int
>  nouveau_debugfs_init(struct nouveau_drm *drm)
>  {
> +	int ret;
> +
>  	drm->debugfs = kzalloc_obj(*drm->debugfs);
>  	if (!drm->debugfs)
>  		return -ENOMEM;
>  
> -	return nvif_object_ctor(&drm->client.device.object,
> "debugfsCtrl", 0,
> -				NVIF_CLASS_CONTROL, NULL, 0,
> -				&drm->debugfs->ctrl);
> +	ret = nvif_object_ctor(&drm->client.device.object,
> "debugfsCtrl", 0,
> +			       NVIF_CLASS_CONTROL, NULL, 0,
> +			       &drm->debugfs->ctrl);
> +	if (ret) {
> +		kfree(drm->debugfs);
> +		drm->debugfs = NULL;
> +	}
> +
> +	return ret;
>  }
>  
>  void
> diff --git a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> index 726397ab035d..ffbe7f542ab0 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> @@ -697,6 +697,8 @@ nouveau_hwmon_init(struct drm_device *dev)
>  	if (IS_ERR(hwmon_dev)) {
>  		ret = PTR_ERR(hwmon_dev);
>  		NV_ERROR(drm, "Unable to register hwmon device:
> %d\n", ret);
> +		drm->hwmon = NULL;
> +		kfree(hwmon);
>  		return ret;
>  	}
>