| Message ID | 20240721193506.2330006-1-linux@roeck-us.net (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [1/2] hwmon: (max16065) Fix overflows seen when writing limits | expand |
On Sun, Jul 21, 2024 at 12:35:05PM -0700, Guenter Roeck wrote: > Writing large limits resulted in overflows as reported by module tests. > > in0_lcrit: Suspected overflow: [max=5538, read 0, written 2147483647] > in0_crit: Suspected overflow: [max=5538, read 0, written 2147483647] > in0_min: Suspected overflow: [max=5538, read 0, written 2147483647] > > Fix the problem by clamping prior to multiplications and the use of > DIV_ROUND_CLOSEST, and by using consistent variable types. > > Fixes: f5bae2642e3d ("hwmon: Driver for MAX16065 System Manager and compatibles") > Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
diff --git a/drivers/hwmon/max16065.c b/drivers/hwmon/max16065.c index 7ce9a89f93a0..5b2a174c6bad 100644 --- a/drivers/hwmon/max16065.c +++ b/drivers/hwmon/max16065.c @@ -114,9 +114,10 @@ static inline int LIMIT_TO_MV(int limit, int range) return limit * range / 256; } -static inline int MV_TO_LIMIT(int mv, int range) +static inline int MV_TO_LIMIT(unsigned long mv, int range) { - return clamp_val(DIV_ROUND_CLOSEST(mv * 256, range), 0, 255); + mv = clamp_val(mv, 0, ULONG_MAX / 256); + return DIV_ROUND_CLOSEST(clamp_val(mv * 256, 0, range * 255), range); } static inline int ADC_TO_CURR(int adc, int gain)
Writing large limits resulted in overflows as reported by module tests. in0_lcrit: Suspected overflow: [max=5538, read 0, written 2147483647] in0_crit: Suspected overflow: [max=5538, read 0, written 2147483647] in0_min: Suspected overflow: [max=5538, read 0, written 2147483647] Fix the problem by clamping prior to multiplications and the use of DIV_ROUND_CLOSEST, and by using consistent variable types. Fixes: f5bae2642e3d ("hwmon: Driver for MAX16065 System Manager and compatibles") Signed-off-by: Guenter Roeck <linux@roeck-us.net> --- drivers/hwmon/max16065.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)