From: Guenter Roeck <linux@roeck-us.net>
Date: Mon, 19 Jan 2015 17:16:53 +0000 (-0800)
Subject: hwmon: (jc42) Fix integer overflow when writing hysteresis value
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e2c26f058e31619b548046b84fe2c2116cb5016f;p=linux-beck.git

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>
---

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)