[PATCH 3.12 020/118] hwmon: Prevent some divide by zeros in FAN_TO_REG()
From: Greg Kroah-Hartman
Date: Wed Dec 18 2013 - 16:47:35 EST
3.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
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@xxxxxxxxxx>
Acked-by: Roger Lucas <vt8231@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jean Delvare <khali@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -94,6 +94,8 @@ static inline u8 FAN_TO_REG(long rpm, in
{
if (rpm <= 0)
return 255;
+ if (rpm > 1350000)
+ return 1;
return clamp_val((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
}
--- a/drivers/hwmon/sis5595.c
+++ b/drivers/hwmon/sis5595.c
@@ -141,6 +141,8 @@ static inline u8 FAN_TO_REG(long rpm, in
{
if (rpm <= 0)
return 255;
+ if (rpm > 1350000)
+ return 1;
return clamp_val((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
}
--- a/drivers/hwmon/vt8231.c
+++ b/drivers/hwmon/vt8231.c
@@ -145,7 +145,7 @@ 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 clamp_val(1310720 / (rpm * div), 1, 255);
}
--
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