[lm-sensors] [PATCH 2/4] hwmon: (applesmc) Do not return random value in error case

[Jean Delvare]

On Tue, 19 Jun 2012 08:46:41 -0700, Guenter Roeck wrote:
> If a bad parameter is passed to applesmc_read_motion_sensor(), an uninitialized
> and thus arbitrary value is returned. Fix by returning immediately if a bad
> parameter is detected.
> 
> Cc: Henrik Rydberg <rydberg at euromail.se>
> Signed-off-by: Guenter Roeck <linux at roeck-us.net>
> ---
>  drivers/hwmon/applesmc.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c
> index f082e48..cc8dd57 100644
> --- a/drivers/hwmon/applesmc.c
> +++ b/drivers/hwmon/applesmc.c
> @@ -450,7 +450,7 @@ static int applesmc_read_motion_sensor(int index, s16 *value)
>  		ret = applesmc_read_key(MOTION_SENSOR_Z_KEY, buffer, 2);
>  		break;
>  	default:
> -		ret = -EINVAL;
> +		return -EINVAL;
>  	}
>  
>  	*value = ((s16)buffer[0] << 8) | buffer[1];

It doesn't really matter as this code is never executed anyway. That
would be a driver bug if it was. A better fix would probably be to get
rid of this branch altogether.

-- 
Jean Delvare