Re: [PATCH] platform/x86: Fix NULL deref in amd_isp_probe

[Mario Limonciello]

On 8/10/26 16:52, Nirujogi, Pratap wrote:
> On 8/9/2026 11:24 PM, Xueqin Luo wrote:
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> >
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> >
> >
> > amd_isp_probe() uses ACPI_COMPANION() without NULL check. Add it to
> > prevent crash when driver_override matches a device without ACPI
> > companion.
> >
> > Fixes: e1af6f0146d6 ("platform/x86: Update swnode graph for amd isp4")
> > Signed-off-by: Xueqin Luo <luoxueqin@xxxxxxxxxx>
> > ---
> >   drivers/platform/x86/amd/amd_isp4.c | 7 +++++++
> >   1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/platform/x86/amd/amd_isp4.c b/drivers/platform/ 
> > x86/amd/amd_isp4.c
> > index 0d494899502c..0026d6663c5c 100644
> > --- a/drivers/platform/x86/amd/amd_isp4.c
> > +++ b/drivers/platform/x86/amd/amd_isp4.c
> > @@ -379,6 +379,11 @@ static int amd_isp_probe(struct platform_device 
> > *pdev)
> >                  goto error_unregister_sw_node;
> >
> >          adev = ACPI_COMPANION(&pdev->dev);
> > +       if (!adev) {
> > +               ret = -ENODEV;
> > +               goto error_unregister_notifier;
> > +       }
> > +
> >          /* initialize root amd_camera_node */
> >          adev->driver_data = (void *)pinfo->swnodes[0];
> >
> > @@ -388,6 +393,8 @@ static int amd_isp_probe(struct platform_device 
> > *pdev)
> >          platform_set_drvdata(pdev, isp4_platform);
> >          return 0;
> >
> > +error_unregister_notifier:
> > +       bus_unregister_notifier(&i2c_bus_type, &isp4_platform->i2c_nb);
> >   error_unregister_sw_node:
> >          software_node_unregister_node_group(isp4_platform->pinfo- 
> > >swnodes);
> >          return ret;
> LGTM. I agree that adding the NULL check is good practice. That said, I 
> believe it's not strictly needed as the device_get_match_data() in 
> line#366 is expected to fail if there is no ACPI companion.

It sounds like it's essentially dead code then.

> https://github.com/torvalds/linux/blob/master/drivers/platform/x86/amd/ 
> amd_isp4.c#L366
>
> Reviewed-by: Pratap Nirujogi <pratap.nirujogi@xxxxxxx>
>
> > --
> > 2.43.0