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

["Nirujogi, Pratap" <pnirujog@amd.com>]

On 8/9/2026 11:24 PM, Xueqin Luo wrote:
> [You don't often get email from luoxueqin@kylinos.cn. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
> 
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
> 
> 
> 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@kylinos.cn>
> ---
>   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.

https://github.com/torvalds/linux/blob/master/drivers/platform/x86/amd/amd_isp4.c#L366

Reviewed-by: Pratap Nirujogi <pratap.nirujogi@amd.com>

> --
> 2.43.0
>