From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f193.google.com ([209.85.210.193]:39181 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392288AbeLUXik (ORCPT ); Fri, 21 Dec 2018 18:38:40 -0500 Date: Fri, 21 Dec 2018 15:38:36 -0800 From: Guenter Roeck To: Kangjie Lu Cc: pakki001@umn.edu, Jean Delvare , linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] hwmon: (lm80) fix a missing check of bus read in lm80 probe Message-ID: <20181221233836.GA17485@roeck-us.net> References: <20181221191039.1519-1-kjlu@umn.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181221191039.1519-1-kjlu@umn.edu> Sender: linux-hwmon-owner@vger.kernel.org List-Id: linux-hwmon@vger.kernel.org On Fri, Dec 21, 2018 at 01:10:39PM -0600, Kangjie Lu wrote: > In lm80_probe(), if lm80_read_value() fails, it returns a negative > error number which is stored to data->fan[f_min] and will be further > used. We should avoid using the data if the read fails. > > The fix checks if lm80_read_value() fails, and if so, returns with the > error number. > > Signed-off-by: Kangjie Lu Applied. Thanks, Guenter > --- > drivers/hwmon/lm80.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwmon/lm80.c b/drivers/hwmon/lm80.c > index d91333557f04..85f797501aaf 100644 > --- a/drivers/hwmon/lm80.c > +++ b/drivers/hwmon/lm80.c > @@ -627,6 +627,7 @@ static int lm80_probe(struct i2c_client *client, > struct device *dev = &client->dev; > struct device *hwmon_dev; > struct lm80_data *data; > + int rv; > > data = devm_kzalloc(dev, sizeof(struct lm80_data), GFP_KERNEL); > if (!data) > @@ -639,8 +640,14 @@ static int lm80_probe(struct i2c_client *client, > lm80_init_client(client); > > /* A few vars need to be filled upon startup */ > - data->fan[f_min][0] = lm80_read_value(client, LM80_REG_FAN_MIN(1)); > - data->fan[f_min][1] = lm80_read_value(client, LM80_REG_FAN_MIN(2)); > + rv = lm80_read_value(client, LM80_REG_FAN_MIN(1)); > + if (rv < 0) > + return rv; > + data->fan[f_min][0] = rv; > + rv = lm80_read_value(client, LM80_REG_FAN_MIN(2)); > + if (rv < 0) > + return rv; > + data->fan[f_min][1] = rv; > > hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, > data, lm80_groups);