Re: [PATCH v1] drm/sysfb: ofdrm: fix PCI device reference leaks

[Thomas Zimmermann]

Hi

Am 20.04.26 um 22:55 schrieb 최유호:
> Dear Thomas,
>
> This issue was identified during our ongoing static-analysis research
> while reviewing
> kernel code. Specifically, an experimental static analysis tool found
> that we are currently
> developing. The tool is not public yet, so I prefer not to disclose
> further project details
> at this stage. AI was used only for cross-review, not as the primary
> means of finding or
> fixing the bug. I manually reviewed the code and verified the issue
> before sending
> the patch.

Thanks.

Best regards
Thomas

> Best regards,
> Yuho Choi
>
>
> On Mon, 20 Apr 2026 at 02:21, Thomas Zimmermann <tzimmermann@xxxxxxx> wrote:
> > Hi,
> >
> > thanks for the patch.
> >
> > Am 20.04.26 um 02:25 schrieb Yuho Choi:
> > > display_get_pci_dev_of() gets a referenced PCI device via
> > > pci_get_device(). Drop that reference when pci_enable_device() fails and
> > > release it during the managed teardown path after pci_disable_device().
> > >
> > > Without that, ofdrm leaks the pci_dev reference on both the error path
> > > and the normal cleanup path.
> > Did you use an AI to find or fix this bug?
> >
> > https://docs.kernel.org/process/coding-assistants.html
> >
> > Best regards
> > Thomas
> >
> > > Fixes: c8a17756c425 ("drm/ofdrm: Add ofdrm for Open Firmware framebuffers")
> > > Co-developed-by: Myeonghun Pak <mhun512@xxxxxxxxx>
> > > Signed-off-by: Myeonghun Pak <mhun512@xxxxxxxxx>
> > > Co-developed-by: Ijae Kim <ae878000@xxxxxxxxx>
> > > Signed-off-by: Ijae Kim <ae878000@xxxxxxxxx>
> > > Co-developed-by: Taegyu Kim <tmk5904@xxxxxxx>
> > > Signed-off-by: Taegyu Kim <tmk5904@xxxxxxx>
> > > Signed-off-by: Yuho Choi <dbgh9129@xxxxxxxxx>
> > > ---
> > >    drivers/gpu/drm/sysfb/ofdrm.c | 2 ++
> > >    1 file changed, 2 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/sysfb/ofdrm.c b/drivers/gpu/drm/sysfb/ofdrm.c
> > > index d38ba70f4e0d3..247cf13c80a05 100644
> > > --- a/drivers/gpu/drm/sysfb/ofdrm.c
> > > +++ b/drivers/gpu/drm/sysfb/ofdrm.c
> > > @@ -350,6 +350,7 @@ static void ofdrm_pci_release(void *data)
> > >        struct pci_dev *pcidev = data;
> > >
> > >        pci_disable_device(pcidev);
> > > +     pci_dev_put(pcidev);
> > >    }
> > >
> > >    static int ofdrm_device_init_pci(struct ofdrm_device *odev)
> > > @@ -375,6 +376,7 @@ static int ofdrm_device_init_pci(struct ofdrm_device *odev)
> > >        if (ret) {
> > >                drm_err(dev, "pci_enable_device(%s) failed: %d\n",
> > >                        dev_name(&pcidev->dev), ret);
> > > +             pci_dev_put(pcidev);
> > >                return ret;
> > >        }
> > >        ret = devm_add_action_or_reset(&pdev->dev, ofdrm_pci_release, pcidev);
> > --
> > --
> > Thomas Zimmermann
> > Graphics Driver Developer
> > SUSE Software Solutions Germany GmbH
> > Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
> > GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)