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

[Thomas Zimmermann <tzimmermann@suse.de>]

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@suse.de> 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@gmail.com>
>>> Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
>>> Co-developed-by: Ijae Kim <ae878000@gmail.com>
>>> Signed-off-by: Ijae Kim <ae878000@gmail.com>
>>> Co-developed-by: Taegyu Kim <tmk5904@psu.edu>
>>> Signed-off-by: Taegyu Kim <tmk5904@psu.edu>
>>> Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
>>> ---
>>>    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)