hwmon: (jc42) Fix integer overflow when writing hysteresis value

Subtracting an unsigned long from a signed value causes an overflow with large
values. Use clamp_val() to reduce the number range prior to subtracting it
from the temperature limit.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/hwmon/jc42.c b/drivers/hwmon/jc42.c
index f8e3bbbf019c..a46cb65cacb5 100644
--- a/drivers/hwmon/jc42.c
+++ b/drivers/hwmon/jc42.c
@@ -312,7 +312,9 @@ static ssize_t set_temp_crit_hyst(struct device *dev,
         if (kstrtoul(buf, 10, &val) < 0)
                 return -EINVAL;
 
+        val = clamp_val(val, 0, JC42_TEMP_MAX);
         diff = jc42_temp_from_reg(data->temp[t_crit]) - val;
+
         hyst = 0;
         if (diff > 0) {
                 if (diff < 2250)