Re: [PATCH] platform/x86: lenovo-wmi-other: fix uninitialized variable in lenovo wmi-other driver

[Rong Zhang]

Hi Yufei,

The title is too verbose. No need to mention the driver's name twice.

On Sun, 2026-04-26 at 18:27 +0800, Yufei CHENG wrote:
> When the flag relax_fan_constraint is set, local variable 'raw'
> is never assigned, and lwmi_om_hwmon_write() will pass uninitialized
> value to lwmi_om_fan_get_set() resulting in undefined behavior.
> 
> This flag allows user to bypass minimum fan RPM divisor rounding,
> but assignment to 'raw' only happens in the non-relaxed path.
> Fix by defaulting 'raw' to user provided 'val' in the else branch.
> 
> Fixes: 51ed34282f63fab5b3996477cc56135eb4de5284

Please run scripts/checkpatch.pl before submitting patches.

> Signed-off-by: Yufei CHENG <cd345al@xxxxxxxxx>
> ---
>  drivers/platform/x86/lenovo/wmi-other.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/platform/x86/lenovo/wmi-other.c b/drivers/platform/x86/lenovo/wmi-other.c
> index 6040f45aa..6c2febe1a 100644
> --- a/drivers/platform/x86/lenovo/wmi-other.c
> +++ b/drivers/platform/x86/lenovo/wmi-other.c
> @@ -349,6 +349,8 @@ static int lwmi_om_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
>  			 */
>  			if (!relax_fan_constraint)
>  				raw = val / LWMI_FAN_DIV * LWMI_FAN_DIV;
> +			else
> +				raw = val;

What an embarrassing mistake! I missed that when I was adding the code
path for rounding down. Thanks for fixing it.

With formatting issues fixed:

Reviewed-by: Rong Zhang <i@xxxxxxxx>

Thanks,
Rong

>  
>  			err = lwmi_om_fan_get_set(priv, channel, &raw, true);
>  			if (err)