4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Guenter Roeck <linux@xxxxxxxxxxxx>
[ Upstream commit 744ec4477b11c42e2c8de9eb8364675ae7a0bd81 ]
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.
Reviewed-by: Tzung-Bi Shih <tzungbi@xxxxxxxxxx>
Fixes: f5bae2642e3d ("hwmon: Driver for MAX16065 System Manager and compatibles")
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/hwmon/max16065.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/hwmon/max16065.c b/drivers/hwmon/max16065.c
index 162401aaef71b..3015dd1a75141 100644
--- a/drivers/hwmon/max16065.c
+++ b/drivers/hwmon/max16065.c
@@ -117,9 +117,10 @@ 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)
--
2.43.0
