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

[lyude@redhat.com]

On Fri, 2026-10-09 at 23:40 +0200, Danilo Krummrich wrote:
> On Fri Oct 9, 2026 at 11:35 PM CEST, lyude wrote:
> > Reviewed-by: Lyude Paul <lyude@redhat.com>
> > 
> > Will push to drm-misc-fixes in a moment
> 
> Please wait, those are two unrelated fixes with two different Fixes:
> tags, so
> those should be two separate patches.

Thanks, I think my brain just glossed over the tags while looking at
this.

liupeng, could you split these patches up?

> 
> I'm also not sure this is -fixes material. A memory leak in an unwind
> path for
> -rc7 feels wrong.
> 
> Thanks,
> Danilo
> 
> > 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@vger.kernel.org
> > > Reviewed-by: Lyude Paul <lyude@redhat.com>
> > > Signed-off-by: liupeng <liupeng01@kylinos.cn>
> > > ---
> > > 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;
> > >  	}
> > >