[1/4] hwmon: (adm9240) Fix overflows seen when writing into limit attributes

Commit Message

Guenter Roeck Nov. 20, 2016, 10:32 p.m. UTC

Module test reports:

in0_min: Suspected overflow: [3320 vs. 0]
in0_max: Suspected overflow: [3320 vs. 0]
in4_min: Suspected overflow: [15938 vs. 0]
in4_max: Suspected overflow: [15938 vs. 0]
temp1_max: Suspected overflow: [127000 vs. 0]
temp1_max_hyst: Suspected overflow: [127000 vs. 0]
aout_output: Suspected overflow: [1250 vs. 0]

Code analysis reveals that the overflows are caused by conversions
from unsigned long to long to int, combined with multiplications on
passed values.

Signed-off-by: Guenter Roeck <[e-mail]>
---
 drivers/hwmon/adm9240.c | 3 +++
 1 file changed, 3 insertions(+)

Patch

diff --git a/drivers/hwmon/adm9240.c b/drivers/hwmon/adm9240.c
index 2fe1828bd10b..347afacedcf5 100644
--- a/drivers/hwmon/adm9240.c
+++ b/drivers/hwmon/adm9240.c
@@ -98,12 +98,14 @@  static inline unsigned int IN_FROM_REG(u8 reg, int n)
 
 static inline u8 IN_TO_REG(unsigned long val, int n)
 {
+	val = clamp_val(val, 0, INT_MAX / 192 - 12000);
 	return clamp_val(SCALE(val, 192, nom_mv[n]), 0, 255);
 }
 
 /* temperature range: -40..125, 127 disables temperature alarm */
 static inline s8 TEMP_TO_REG(long val)
 {
+	val = clamp_val(val, INT_MIN + 1000, INT_MAX - 1000);
 	return clamp_val(SCALE(val, 1, 1000), -40, 127);
 }
 
@@ -122,6 +124,7 @@  static inline unsigned int FAN_FROM_REG(u8 reg, u8 div)
 /* analog out 0..1250mV */
 static inline u8 AOUT_TO_REG(unsigned long val)
 {
+	val = clamp_val(val, 0, INT_MAX / 255 - 1250);
 	return clamp_val(SCALE(val, 255, 1250), 0, 255);
 }