linux-kernel - Re: [PATCH v2 2/5] platform/x86: wmi: Check if event data is not NULL

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Date: Tue, 20 Feb 2024 01:59:31 +0100
From: Armin Wolf <W_Armin@....de>
To: corentin.chary@...il.com, luke@...nes.dev
Cc: hdegoede@...hat.com, ilpo.jarvinen@...ux.intel.com,
 platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/5] platform/x86: wmi: Check if event data is not NULL

Am 19.02.24 um 12:59 schrieb Armin Wolf:

> WMI event drivers which do not have no_notify_data set expect
> that each WMI event contains valid data. Evaluating _WED however
> might return no data, which can cause issues with such drivers.
>
> Fix this by validating that evaluating _WED did return data.
>
> Signed-off-by: Armin Wolf <W_Armin@....de>
> ---
>   drivers/platform/x86/wmi.c | 11 +++++++++--
>   1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
> index 8fb90b726f50..d0fe8153f803 100644
> --- a/drivers/platform/x86/wmi.c
> +++ b/drivers/platform/x86/wmi.c
> @@ -1210,6 +1210,7 @@ static void wmi_notify_driver(struct wmi_block *wblock)
>   {
>   	struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver);
>   	struct acpi_buffer data = { ACPI_ALLOCATE_BUFFER, NULL };
> +	union acpi_object *obj = NULL;
>   	acpi_status status;
>
>   	if (!driver->no_notify_data) {
> @@ -1218,12 +1219,18 @@ static void wmi_notify_driver(struct wmi_block *wblock)
>   			dev_warn(&wblock->dev.dev, "Failed to get event data\n");
>   			return;
>   		}
> +
> +		obj = data.pointer;
> +		if (!obj) {
> +			dev_warn(&wblock->dev.dev, "Event contains not event data\n");

I just noticed that this should have been "Event contains no event data\n". Should i send
another patch?

Armin Wolf

> +			return;
> +		}
>   	}
>
>   	if (driver->notify)
> -		driver->notify(&wblock->dev, data.pointer);
> +		driver->notify(&wblock->dev, obj);
>
> -	kfree(data.pointer);
> +	kfree(obj);
>   }
>
>   static int wmi_notify_device(struct device *dev, void *data)
> --
> 2.39.2
>
>