| Message ID | 20240713213402.1085599-2-linux@roeck-us.net (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [1/2] hwmon: (max6697) Fix swapped temp{1,8} critical alarms | expand |
On Sat, Jul 13, 2024 at 02:34:02PM -0700, Guenter Roeck wrote: > Using DIV_ROUND_CLOSEST() on an unbound value can result in underflows. > Indeed, module test scripts report: > > temp1_max: Suspected underflow: [min=0, read 255000, written -9223372036854775808] > temp1_crit: Suspected underflow: [min=0, read 255000, written -9223372036854775808] > > Fix by introducing an extra set of clamping. > > Fixes: 5372d2d71c46 ("hwmon: Driver for Maxim MAX6697 and compatibles") > Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
diff --git a/drivers/hwmon/max6697.c b/drivers/hwmon/max6697.c index 1111b2ea55ee..20981f9443dd 100644 --- a/drivers/hwmon/max6697.c +++ b/drivers/hwmon/max6697.c @@ -311,6 +311,7 @@ static ssize_t temp_store(struct device *dev, return ret; mutex_lock(&data->update_lock); + temp = clamp_val(temp, -1000000, 1000000); /* prevent underflow */ temp = DIV_ROUND_CLOSEST(temp, 1000) + data->temp_offset; temp = clamp_val(temp, 0, data->type == max6581 ? 255 : 127); data->temp[nr][index] = temp;
Using DIV_ROUND_CLOSEST() on an unbound value can result in underflows. Indeed, module test scripts report: temp1_max: Suspected underflow: [min=0, read 255000, written -9223372036854775808] temp1_crit: Suspected underflow: [min=0, read 255000, written -9223372036854775808] Fix by introducing an extra set of clamping. Fixes: 5372d2d71c46 ("hwmon: Driver for Maxim MAX6697 and compatibles") Signed-off-by: Guenter Roeck <linux@roeck-us.net> --- drivers/hwmon/max6697.c | 1 + 1 file changed, 1 insertion(+)