From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from bh-25.webhostbox.net ([208.91.199.152]:47287 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752466AbcLHTXt (ORCPT ); Thu, 8 Dec 2016 14:23:49 -0500 From: Guenter Roeck To: Hardware Monitoring Cc: Jean Delvare , Guenter Roeck Subject: [PATCH v2] hwmon: (adm9240) Fix overflows seen when writing into limit attributes Date: Thu, 8 Dec 2016 11:22:29 -0800 Message-Id: <1481224949-4288-1-git-send-email-linux@roeck-us.net> Sender: linux-hwmon-owner@vger.kernel.org List-Id: linux-hwmon@vger.kernel.org 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 --- v2: Improved and simplified clamping drivers/hwmon/adm9240.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/adm9240.c b/drivers/hwmon/adm9240.c index 2fe1828bd10b..72bf2489511e 100644 --- a/drivers/hwmon/adm9240.c +++ b/drivers/hwmon/adm9240.c @@ -98,13 +98,15 @@ static inline unsigned int IN_FROM_REG(u8 reg, int n) static inline u8 IN_TO_REG(unsigned long val, int n) { - return clamp_val(SCALE(val, 192, nom_mv[n]), 0, 255); + val = clamp_val(val, 0, nom_mv[n] * 255 / 192); + return SCALE(val, 192, nom_mv[n]); } /* temperature range: -40..125, 127 disables temperature alarm */ static inline s8 TEMP_TO_REG(long val) { - return clamp_val(SCALE(val, 1, 1000), -40, 127); + val = clamp_val(val, -40000, 127000); + return SCALE(val, 1, 1000); } /* two fans, each with low fan speed limit */ @@ -122,7 +124,8 @@ static inline unsigned int FAN_FROM_REG(u8 reg, u8 div) /* analog out 0..1250mV */ static inline u8 AOUT_TO_REG(unsigned long val) { - return clamp_val(SCALE(val, 255, 1250), 0, 255); + val = clamp_val(val, 0, 1250); + return SCALE(val, 255, 1250); } static inline unsigned int AOUT_FROM_REG(u8 reg) -- 2.5.0