| From | Ben Hutchings <> | Date | Sun, 29 Dec 2013 03:08:44 +0100 | Subject | [PATCH 3.2 140/185] hwmon: Prevent some divide by zeros in FAN_TO_REG() |
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3.2.54-rc1 review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter <dan.carpenter@oracle.com>
commit 3806b45ba4655147a011df03242cc197ab986c43 upstream.
The "rpm * div" operations can overflow here, so this patch adds an upper limit to rpm to prevent that. Jean Delvare helped me with this patch.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Roger Lucas <vt8231@hiddenengine.co.uk> Signed-off-by: Jean Delvare <khali@linux-fr.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- drivers/hwmon/lm78.c | 2 ++ drivers/hwmon/sis5595.c | 2 ++ drivers/hwmon/vt8231.c | 2 +- 3 files changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/hwmon/lm78.c +++ b/drivers/hwmon/lm78.c @@ -90,6 +90,8 @@ static inline u8 FAN_TO_REG(long rpm, in { if (rpm <= 0) return 255; + if (rpm > 1350000) + return 1; return SENSORS_LIMIT((1350000 + rpm * div / 2) / (rpm * div), 1, 254); } --- a/drivers/hwmon/sis5595.c +++ b/drivers/hwmon/sis5595.c @@ -133,6 +133,8 @@ static inline u8 FAN_TO_REG(long rpm, in { if (rpm <= 0) return 255; + if (rpm > 1350000) + return 1; return SENSORS_LIMIT((1350000 + rpm * div / 2) / (rpm * div), 1, 254); } --- a/drivers/hwmon/vt8231.c +++ b/drivers/hwmon/vt8231.c @@ -139,7 +139,7 @@ static const u8 regtempmin[] = { 0x3a, 0 */ static inline u8 FAN_TO_REG(long rpm, int div) { - if (rpm == 0) + if (rpm <= 0 || rpm > 1310720) return 0; return SENSORS_LIMIT(1310720 / (rpm * div), 1, 255); }
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