From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D892CC433F5 for ; Fri, 20 May 2022 17:13:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352075AbiETRNb (ORCPT ); Fri, 20 May 2022 13:13:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238817AbiETRN2 (ORCPT ); Fri, 20 May 2022 13:13:28 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A809AAFAFD; Fri, 20 May 2022 10:13:27 -0700 (PDT) Received: from fraeml713-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4L4YFx32Hbz6H6mq; Sat, 21 May 2022 01:13:09 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml713-chm.china.huawei.com (10.206.15.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 20 May 2022 19:13:25 +0200 Received: from localhost (10.122.247.231) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 20 May 2022 18:13:24 +0100 Date: Fri, 20 May 2022 18:13:23 +0100 From: Jonathan Cameron To: Yongzhi Liu CC: , , , , , , , Subject: Re: [PATCH v2] iio: vadc: Fix potential dereference of NULL pointer Message-ID: <20220520181323.00002892@huawei.com> In-Reply-To: <1652939455-123139-1-git-send-email-lyz_cs@pku.edu.cn> References: <1652939455-123139-1-git-send-email-lyz_cs@pku.edu.cn> Organization: Huawei Technologies R&D (UK) Ltd. X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.29; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.122.247.231] X-ClientProxiedBy: lhreml737-chm.china.huawei.com (10.201.108.187) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 18 May 2022 22:50:55 -0700 Yongzhi Liu wrote: > The return value of vadc_get_channel() needs to be checked > to avoid use of NULL pointer. Fix this by adding the null > pointer check on prop. > > Fixes: 0917de94c ("iio: vadc: Qualcomm SPMI PMIC voltage ADC driver") > > Signed-off-by: Yongzhi Liu This function has a lot of goto err; where err just results in a print. My suggestion is to just drop that print and use error specific prints as you have done here, then use direct returns. > --- > drivers/iio/adc/qcom-spmi-vadc.c | 23 ++++++++++++++++++++++- > 1 file changed, 22 insertions(+), 1 deletion(-) > > diff --git a/drivers/iio/adc/qcom-spmi-vadc.c b/drivers/iio/adc/qcom-spmi-vadc.c > index 34202ba..9fa61fb 100644 > --- a/drivers/iio/adc/qcom-spmi-vadc.c > +++ b/drivers/iio/adc/qcom-spmi-vadc.c > @@ -358,14 +358,25 @@ static int vadc_measure_ref_points(struct vadc_priv *vadc) > vadc->graph[VADC_CALIB_ABSOLUTE].dx = VADC_ABSOLUTE_RANGE_UV; > > prop = vadc_get_channel(vadc, VADC_REF_1250MV); > + if (!prop) { > + dev_err(vadc->dev, "Please define 1.25V channel\n"); > + ret = -ENODEV; > + goto err; > + } > ret = vadc_do_conversion(vadc, prop, &read_1); > if (ret) > goto err; > > /* Try with buffered 625mV channel first */ > prop = vadc_get_channel(vadc, VADC_SPARE1); > - if (!prop) > + if (!prop) { > prop = vadc_get_channel(vadc, VADC_REF_625MV); > + if (!prop) { > + dev_err(vadc->dev, "Please define 0.625V channel\n"); > + ret = -ENODEV; > + goto err; > + } > + } > > ret = vadc_do_conversion(vadc, prop, &read_2); > if (ret) > @@ -381,11 +392,21 @@ static int vadc_measure_ref_points(struct vadc_priv *vadc) > > /* Ratiometric calibration */ > prop = vadc_get_channel(vadc, VADC_VDD_VADC); > + if (!prop) { > + dev_err(vadc->dev, "Please define VDD channel\n"); > + ret = -ENODEV; > + goto err; > + } > ret = vadc_do_conversion(vadc, prop, &read_1); > if (ret) > goto err; > > prop = vadc_get_channel(vadc, VADC_GND_REF); > + if (!prop) { > + dev_err(vadc->dev, "Please define GND channel\n"); > + ret = -ENODEV; > + goto err; > + } > ret = vadc_do_conversion(vadc, prop, &read_2); > if (ret) > goto err;