From 87cdfa9d60f4f40e6d71b04b10b36d9df3c89282 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Tue, 27 Dec 2016 14:15:07 -0800 Subject: [PATCH] hwmon: (gl520sm) Fix overflows and crash seen when writing into limit attributes Writes into limit attributes can overflow due to multplications and additions with unbound input values. Writing into fan limit attributes can result in a crash with a division by zero if very large values are written and the fan divider is larger than 1. Signed-off-by: Guenter Roeck --- drivers/hwmon/gl520sm.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/drivers/hwmon/gl520sm.c b/drivers/hwmon/gl520sm.c index f24a614a10aa..4ff32ee67fb6 100644 --- a/drivers/hwmon/gl520sm.c +++ b/drivers/hwmon/gl520sm.c @@ -208,11 +208,13 @@ static ssize_t cpu0_vid_show(struct device *dev, } static DEVICE_ATTR_RO(cpu0_vid); -#define VDD_FROM_REG(val) (((val) * 95 + 2) / 4) -#define VDD_TO_REG(val) clamp_val((((val) * 4 + 47) / 95), 0, 255) +#define VDD_FROM_REG(val) DIV_ROUND_CLOSEST((val) * 95, 4) +#define VDD_CLAMP(val) clamp_val(val, 0, 255 * 95 / 4) +#define VDD_TO_REG(val) DIV_ROUND_CLOSEST(VDD_CLAMP(val) * 4, 95) -#define IN_FROM_REG(val) ((val) * 19) -#define IN_TO_REG(val) clamp_val((((val) + 9) / 19), 0, 255) +#define IN_FROM_REG(val) ((val) * 19) +#define IN_CLAMP(val) clamp_val(val, 0, 255 * 19) +#define IN_TO_REG(val) DIV_ROUND_CLOSEST(IN_CLAMP(val), 19) static ssize_t get_in_input(struct device *dev, struct device_attribute *attr, char *buf) @@ -349,8 +351,13 @@ static SENSOR_DEVICE_ATTR(in4_max, S_IRUGO | S_IWUSR, #define DIV_FROM_REG(val) (1 << (val)) #define FAN_FROM_REG(val, div) ((val) == 0 ? 0 : (480000 / ((val) << (div)))) -#define FAN_TO_REG(val, div) ((val) <= 0 ? 0 : \ - clamp_val((480000 + ((val) << ((div)-1))) / ((val) << (div)), 1, 255)) + +#define FAN_BASE(div) (480000 >> (div)) +#define FAN_CLAMP(val, div) clamp_val(val, FAN_BASE(div) / 255, \ + FAN_BASE(div)) +#define FAN_TO_REG(val, div) ((val) == 0 ? 0 : \ + DIV_ROUND_CLOSEST(480000, \ + FAN_CLAMP(val, div) << (div))) static ssize_t get_fan_input(struct device *dev, struct device_attribute *attr, char *buf) @@ -513,9 +520,9 @@ static SENSOR_DEVICE_ATTR(fan2_div, S_IRUGO | S_IWUSR, get_fan_div, set_fan_div, 1); static DEVICE_ATTR_RW(fan1_off); -#define TEMP_FROM_REG(val) (((val) - 130) * 1000) -#define TEMP_TO_REG(val) clamp_val(((((val) < 0 ? \ - (val) - 500 : (val) + 500) / 1000) + 130), 0, 255) +#define TEMP_FROM_REG(val) (((val) - 130) * 1000) +#define TEMP_CLAMP(val) clamp_val(val, -130000, 125000) +#define TEMP_TO_REG(val) (DIV_ROUND_CLOSEST(TEMP_CLAMP(val), 1000) + 130) static ssize_t get_temp_input(struct device *dev, struct device_attribute *attr, char *buf) -- 2.20.1