Commit 55840b9e authored by Guenter Roeck's avatar Guenter Roeck
Browse files

hwmon: (lm90) Prevent integer overflow/underflow in hysteresis calculations 



Commit b50aa496 ("hwmon: (lm90) Prevent integer underflows of
temperature calculations") addressed a number of underflow situations
when writing temperature limits. However, it missed one situation, seen
when an attempt is made to set the hysteresis value to MAX_LONG and the
critical temperature limit is negative.

Use clamp_val() when setting the hysteresis temperature to ensure that
the provided value can never overflow or underflow.

Fixes: b50aa496 ("hwmon: (lm90) Prevent integer underflows of temperature calculations")
Cc: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: default avatarDmitry Osipenko <digetx@gmail.com>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent fce15c45

drivers/hwmon/lm90.c

+2 −2
Original line number Diff line number Diff line
@@ -1160,8 +1160,8 @@ static int lm90_set_temphyst(struct lm90_data *data, long val) 
	else

		temp = temp_from_s8(data->temp8[LOCAL_CRIT]);



	/* prevent integer underflow */

	val = max(val, -128000l);

	/* prevent integer overflow/underflow */

	val = clamp_val(val, -128000l, 255000l);



	data->temp_hyst = hyst_to_reg(temp - val);

	err = i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,