hwmon: (lm85) Fix various errors on attribute writes

Temperature limit register writes did not account for negative numbers.
As a result, writing -127000 resulted in -126000 written into the
temperature limit register. This problem affected temp[1-3]_min,
temp[1-3]_max, temp[1-3]_auto_temp_crit, and temp[1-3]_auto_temp_min.

When writing pwm[1-3]_freq, a long variable was auto-converted into an int
without range check. Wiring values larger than MAXINT resulted in unexpected
register values.

When writing temp[1-3]_auto_temp_max, an unsigned long variable was
auto-converted into an int without range check. Writing values larger than
MAXINT resulted in unexpected register values.

vrm is an u8, so the written value needs to be limited to [0, 255].

Cc: Axel Lin <axel.lin@ingics.com>
Cc: stable@vger.kernel.org
Reviewed-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/hwmon/lm85.c b/drivers/hwmon/lm85.c
index b0129a54e1a6..ef627ea71cc8 100644
--- a/drivers/hwmon/lm85.c
+++ b/drivers/hwmon/lm85.c
@@ -155,7 +155,7 @@ static inline u16 FAN_TO_REG(unsigned long val)
 
 /* Temperature is reported in .001 degC increments */
 #define TEMP_TO_REG(val)        \
-                clamp_val(SCALE(val, 1000, 1), -127, 127)
+                DIV_ROUND_CLOSEST(clamp_val((val), -127000, 127000), 1000)
 #define TEMPEXT_FROM_REG(val, ext)      \
                 SCALE(((val) << 4) + (ext), 16, 1000)
 #define TEMP_FROM_REG(val)      ((val) * 1000)
@@ -189,7 +189,7 @@ static const int lm85_range_map[] = {
         13300, 16000, 20000, 26600, 32000, 40000, 53300, 80000
 };
 
-static int RANGE_TO_REG(int range)
+static int RANGE_TO_REG(long range)
 {
         int i;
 
@@ -211,7 +211,7 @@ static const int adm1027_freq_map[8] = { /* 1 Hz */
         11, 15, 22, 29, 35, 44, 59, 88
 };
 
-static int FREQ_TO_REG(const int *map, int freq)
+static int FREQ_TO_REG(const int *map, unsigned long freq)
 {
         int i;
 
@@ -460,6 +460,9 @@ static ssize_t store_vrm_reg(struct device *dev, struct device_attribute *attr,
         if (err)
                 return err;
 
+        if (val > 255)
+                return -EINVAL;
+
         data->vrm = val;
         return count;
 }