[lvc-project] [PATCH] hwmon: (asus-ec-sensors) check sensor index in read_string()

[Eugene Shalygin]

Hi,

maybe return the value of sensor_index, which already contains the
error code, rather than EINVAL?

Eugene

On Thu, 24 Apr 2025 at 22:27, Alexei Safin <a.safin at rosa.ru> wrote:
>
> Prevent a potential invalid memory access when the requested sensor
> is not found.
>
> find_ec_sensor_index() may return a negative value (e.g. -ENOENT),
> but its result was used without checking, which could lead to
> undefined behavior when passed to get_sensor_info().
>
> Add a proper check to return -EINVAL if sensor_index is negative.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Fixes: d0ddfd241e57 ("hwmon: (asus-ec-sensors) add driver for ASUS EC")
> Signed-off-by: Alexei Safin <a.safin at rosa.ru>
> ---
>  drivers/hwmon/asus-ec-sensors.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/hwmon/asus-ec-sensors.c b/drivers/hwmon/asus-ec-sensors.c
> index d893cfd1cb82..769725ea18db 100644
> --- a/drivers/hwmon/asus-ec-sensors.c
> +++ b/drivers/hwmon/asus-ec-sensors.c
> @@ -839,6 +839,10 @@ static int asus_ec_hwmon_read_string(struct device *dev,
>  {
>         struct ec_sensors_data *state = dev_get_drvdata(dev);
>         int sensor_index = find_ec_sensor_index(state, type, channel);
> +
> +       if (sensor_index < 0)
> +               return -EINVAL;
> +
>         *str = get_sensor_info(state, sensor_index)->label;
>
>         return 0;
> --
> 2.39.5 (Apple Git-154)
>