Re: [PATCH] hwmon: asus_atk0110.c fix uninitialized data access
From: Luca Tettamanti
Date: Thu Mar 23 2017 - 11:33:03 EST
On 23 March 2017 at 16:03, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> The latest gcc-7 snapshot adds a warning to point out that when
> atk_read_value_old or atk_read_value_new fails, we copy
> uninitialized data into sensor->cached_value:
>
> drivers/hwmon/asus_atk0110.c: In function 'atk_input_show':
> drivers/hwmon/asus_atk0110.c:651:26: error: 'value' may be used uninitialized in this function [-Werror=maybe-uninitialized]
Ops, thanks for catching this.
>
> Adding an error check avoids this. All versions of the driver
> are affected.
>
> Fixes: 2c03d07ad54d ("hwmon: Add Asus ATK0110 support")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Reviewed-by: Luca Tettamanti <kronos.it@xxxxxxxxx>
> ---
> drivers/hwmon/asus_atk0110.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/hwmon/asus_atk0110.c b/drivers/hwmon/asus_atk0110.c
> index cccef87963e0..975c43d446f8 100644
> --- a/drivers/hwmon/asus_atk0110.c
> +++ b/drivers/hwmon/asus_atk0110.c
> @@ -646,6 +646,9 @@ static int atk_read_value(struct atk_sensor_data *sensor, u64 *value)
> else
> err = atk_read_value_new(sensor, value);
>
> + if (err)
> + return err;
> +
> sensor->is_valid = true;
> sensor->last_updated = jiffies;
> sensor->cached_value = *value;
> --
> 2.9.0
>