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[173.230.104.23]) by smtp.gmail.com with ESMTPSA id a16sm10381370ioh.48.2018.12.20.22.13.24 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 20 Dec 2018 22:13:24 -0800 (PST) From: Kangjie Lu To: kjlu@umn.edu Cc: pakki001@umn.edu, Jean Delvare , Guenter Roeck , linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] hwmon: lm80: fix a missing check of return value Date: Fri, 21 Dec 2018 00:13:03 -0600 Message-Id: <20181221061304.59684-1-kjlu@umn.edu> X-Mailer: git-send-email 2.17.2 (Apple Git-113) Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If lm80_read_value() fails, it returns a negative number instead of the correct read data. Therefore, we should avoid using the data if it fails. The fix checks if lm80_read_value() fails, and if so, returns with the error number. Signed-off-by: Kangjie Lu --- drivers/hwmon/lm80.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/hwmon/lm80.c b/drivers/hwmon/lm80.c index 08e3945a6fbf..fca6363cd77f 100644 --- a/drivers/hwmon/lm80.c +++ b/drivers/hwmon/lm80.c @@ -360,9 +360,11 @@ static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr, struct i2c_client *client = data->client; unsigned long min, val; u8 reg; - int err = kstrtoul(buf, 10, &val); - if (err < 0) - return err; + int ret; + + ret = kstrtoul(buf, 10, &val); + if (ret < 0) + return ret; /* Save fan_min */ mutex_lock(&data->update_lock); @@ -390,8 +392,11 @@ static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr, return -EINVAL; } - reg = (lm80_read_value(client, LM80_REG_FANDIV) & - ~(3 << (2 * (nr + 1)))) | (data->fan_div[nr] << (2 * (nr + 1))); + ret = lm80_read_value(client, LM80_REG_FANDIV); + if (ret < 0) + return ret; + reg = (ret & ~(3 << (2 * (nr + 1)))) + | (data->fan_div[nr] << (2 * (nr + 1))); lm80_write_value(client, LM80_REG_FANDIV, reg); /* Restore fan_min */