Re: [PATCH] platform/x86: Add ACPI_COMPANION() NULL check in topstar_acpi_probe

[Wysocki, Rafael J]

On 8/11/2026 4:21 AM, Xueqin Luo wrote:
> Add NULL check for ACPI_COMPANION() in topstar_acpi_probe() to prevent
> NULL pointer dereference when driver_override matches a device without
> ACPI companion.
>
> Fixes: 3471415c8186 ("platform/x86: topstar-laptop: Convert ACPI driver to a platform one")
> Signed-off-by: Xueqin Luo <luoxueqin@xxxxxxxxxx>

I'm not sure why I haven't sent a patch to address this, so

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>


> ---
>   drivers/platform/x86/topstar-laptop.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/platform/x86/topstar-laptop.c b/drivers/platform/x86/topstar-laptop.c
> index 0e842c55dcc5..730a599abf0f 100644
> --- a/drivers/platform/x86/topstar-laptop.c
> +++ b/drivers/platform/x86/topstar-laptop.c
> @@ -287,10 +287,14 @@ static const struct dmi_system_id topstar_dmi_ids[] = {
>   
>   static int topstar_acpi_probe(struct platform_device *pdev)
>   {
> -	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
> +	struct acpi_device *device;
>   	struct topstar_laptop *topstar;
>   	int err;
>   
> +	device = ACPI_COMPANION(&pdev->dev);
> +	if (!device)
> +		return -ENODEV;
> +
>   	dmi_check_system(topstar_dmi_ids);
>   
>   	topstar = kzalloc_obj(struct topstar_laptop);