On 12/12/2016 01:33 AM, Jean Delvare wrote:
Hi Guenter,
On Sun, 4 Dec 2016 20:55:35 -0800, Guenter Roeck wrote:
Writes into voltage limit, temperature limit, and temperature zone
attributes can overflow due to unchecked parameters to multiplications
and additions.
Cc: Juerg Haefliger <jue...@gmail.com>
Signed-off-by: Guenter Roeck <li...@roeck-us.net>
---
drivers/hwmon/dme1737.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/hwmon/dme1737.c b/drivers/hwmon/dme1737.c
index 8763c4a8280c..29d082c12c74 100644
--- a/drivers/hwmon/dme1737.c
+++ b/drivers/hwmon/dme1737.c
@@ -279,7 +279,8 @@ static inline int IN_FROM_REG(int reg, int nominal, int res)
static inline int IN_TO_REG(long val, int nominal)
{
- return clamp_val((val * 192 + nominal / 2) / nominal, 0, 255);
+ return DIV_ROUND_CLOSEST(clamp_val(val, 0, 255 * nominal / 192) * 192,
+ nominal);
}
/*
@@ -295,7 +296,7 @@ static inline int TEMP_FROM_REG(int reg, int res)
static inline int TEMP_TO_REG(long val)
{
- return clamp_val((val < 0 ? val - 500 : val + 500) / 1000, -128, 127);
+ return DIV_ROUND_CLOSEST(clamp_val(val, -128000, 127000), 1000);
}
/* Temperature range */
@@ -1028,6 +1029,8 @@ static ssize_t set_zone(struct device *dev, struct
device_attribute *attr,
if (err)
return err;
+ val = clamp_val(val, -256000, 255000);
Where do these values come from? I would have naively expected the
auto-pwm temperature values to have the same range as the temperature
channels themselves.
Not related to real limits, just a "basic" clamp since the real clamp happens
later
anyway.
Also in the case of SYS_ZONE_AUTO_POINT1_TEMP and
SYS_ZONE_AUTO_POINT3_TEMP, TEMP_TO_REG() is called, which already
performs the clamping, so it is redundant. So maybe it would be better
to have a "dedicated" clamp for the SYS_ZONE_AUTO_POINT1_TEMP_HYST and
SYS_ZONE_AUTO_POINT2_TEMP cases?
Yrd, I noticed. Makes sense. Let me think about it.
Thanks,
Guenter
+
mutex_lock(&data->update_lock);
switch (fn) {
case SYS_ZONE_AUTO_POINT1_TEMP_HYST:
--
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