Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752026AbdINQ0H (ORCPT ); Thu, 14 Sep 2017 12:26:07 -0400 Received: from omzsmtpe01.verizonbusiness.com ([199.249.25.210]:51806 "EHLO omzsmtpe01.verizonbusiness.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751255AbdINPwI (ORCPT ); Thu, 14 Sep 2017 11:52:08 -0400 From: "Levin, Alexander (Sasha Levin)" Cc: Guenter Roeck , "Levin, Alexander (Sasha Levin)" X-Host: viking.odc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH for 4.9 25/59] hwmon: (gl520sm) Fix overflows and crash seen when writing into limit attributes Thread-Topic: [PATCH for 4.9 25/59] hwmon: (gl520sm) Fix overflows and crash seen when writing into limit attributes Thread-Index: AQHTLXFKRHRLttMIkka/zlyRCpiAmw== Date: Thu, 14 Sep 2017 15:51:12 +0000 Message-ID: <20170914155051.8289-25-alexander.levin@verizon.com> References: <20170914155051.8289-1-alexander.levin@verizon.com> In-Reply-To: <20170914155051.8289-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v8EGQPOd014830 Content-Length: 2859 Lines: 68 From: Guenter Roeck [ 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 Signed-off-by: Sasha Levin --- 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 dee93ec87d02..84e0994aafdd 100644 --- a/drivers/hwmon/gl520sm.c +++ b/drivers/hwmon/gl520sm.c @@ -208,11 +208,13 @@ static ssize_t get_cpu_vid(struct device *dev, struct device_attribute *attr, } 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 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, 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) -- 2.11.0