4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guenter Roeck <linux@xxxxxxxxxxxx> [ Upstream commit 87cdfa9d60f4f40e6d71b04b10b36d9df3c89282 ] 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 <linux@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/hwmon/gl520sm.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) --- a/drivers/hwmon/gl520sm.c +++ b/drivers/hwmon/gl520sm.c @@ -208,11 +208,13 @@ static ssize_t get_cpu_vid(struct device } static DEVICE_ATTR(cpu0_vid, S_IRUGO, get_cpu_vid, NULL); -#define VDD_FROM_REG(val) (((val) * 95 + 2) / 4) -#define VDD_TO_REG(val) clamp_val((((val) * 4 + 47) / 95), 0, 255) - -#define IN_FROM_REG(val) ((val) * 19) -#define IN_TO_REG(val) clamp_val((((val) + 9) / 19), 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_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_IRU #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_IR static DEVICE_ATTR(fan1_off, S_IRUGO | S_IWUSR, get_fan_off, set_fan_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)