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 X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 049F7C04EB9 for ; Sat, 1 Dec 2018 16:35:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BE3762146F for ; Sat, 1 Dec 2018 16:35:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Z1YhHLsF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BE3762146F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726992AbeLBDsX (ORCPT ); Sat, 1 Dec 2018 22:48:23 -0500 Received: from mail.kernel.org ([198.145.29.99]:34342 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726880AbeLBDsW (ORCPT ); Sat, 1 Dec 2018 22:48:22 -0500 Received: from archlinux (cpc91196-cmbg18-2-0-cust659.5-4.cable.virginm.net [81.96.234.148]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 533D520834; Sat, 1 Dec 2018 16:35:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1543682128; bh=ZJGyaS5AMWarTZboJA5n9nFPCuZ39Wbyi6eAwPW+NdY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Z1YhHLsFywMvzzfPMQrI9yHNezWu5YUtTkOfpZMjXXl4Q0ZvmppgjSq/p9FqzR+RZ s+ACeyxZXh4L7ltRhjb9etC0Aw17ok3PofwxNAx2Mf33KgsZx4MlRYJrdi7QTxDHx9 owFc9ohcBJsMOEwO8+Fn0lbBK+I1UUsldlt1PwvM= Date: Sat, 1 Dec 2018 16:35:23 +0000 From: Jonathan Cameron To: Nicholas Mc Guire Cc: Lars-Peter Clausen , Michael Hennerich , Hartmut Knaack , Peter Meerwald-Stadler , Greg Kroah-Hartman , Dan Carpenter , Joe Perches , linux-iio@vger.kernel.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V2] staging: iio: adc: ad7280a: check for devm_kasprint() failure Message-ID: <20181201163523.52a84b47@archlinux> In-Reply-To: <1543338304-892-1-git-send-email-hofrat@osadl.org> References: <1543338304-892-1-git-send-email-hofrat@osadl.org> X-Mailer: Claws Mail 3.17.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 27 Nov 2018 18:05:04 +0100 Nicholas Mc Guire wrote: > devm_kasprintf() may return NULL on failure of internal allocation thus > the assignments to attr.name are not safe if not checked. On error > ad7280_attr_init() returns a negative return so -ENOMEM should be > OK here (passed on as return value of the probe function). To make the > error case more readable a temporary iio_attr is introduced and the code > refactored. > > Signed-off-by: Nicholas Mc Guire > Fixes: 2051f25d2a26 ("iio: adc: New driver for AD7280A Lithium Ion Battery Monitoring System2") Hmm. If this had been other than to a staging driver I think I would have asked you to split this into a rework patch doing the local variable change, then one actually making the fix. Good result though, so as it's in staging we'll go with this :) Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > --- > > V2: use a tmp pointer to iio_attr to make the error check more readable > as proposed by Dan Carpenter > > Problem located with an experimental coccinelle script > > Patch was compile tested with: x86_64_defconfig + STAGING=y > SPI=y, IIO=y, AD7280=m > > Patch is against 4.20-rc4 (localversion-next is next-20181127) > > drivers/staging/iio/adc/ad7280a.c | 43 +++++++++++++++++++-------------------- > 1 file changed, 21 insertions(+), 22 deletions(-) > > diff --git a/drivers/staging/iio/adc/ad7280a.c b/drivers/staging/iio/adc/ad7280a.c > index 0bb9ab1..7a0ba26 100644 > --- a/drivers/staging/iio/adc/ad7280a.c > +++ b/drivers/staging/iio/adc/ad7280a.c > @@ -561,6 +561,7 @@ static int ad7280_attr_init(struct ad7280_state *st) > { > int dev, ch, cnt; > unsigned int index; > + struct iio_dev_attr *iio_attr; > > st->iio_attr = devm_kcalloc(&st->spi->dev, 2, sizeof(*st->iio_attr) * > (st->slave_num + 1) * AD7280A_CELLS_PER_DEV, > @@ -571,37 +572,35 @@ static int ad7280_attr_init(struct ad7280_state *st) > for (dev = 0, cnt = 0; dev <= st->slave_num; dev++) > for (ch = AD7280A_CELL_VOLTAGE_1; ch <= AD7280A_CELL_VOLTAGE_6; > ch++, cnt++) { > + iio_attr = &st->iio_attr[cnt]; > index = dev * AD7280A_CELLS_PER_DEV + ch; > - st->iio_attr[cnt].address = > - ad7280a_devaddr(dev) << 8 | ch; > - st->iio_attr[cnt].dev_attr.attr.mode = > - 0644; > - st->iio_attr[cnt].dev_attr.show = > - ad7280_show_balance_sw; > - st->iio_attr[cnt].dev_attr.store = > - ad7280_store_balance_sw; > - st->iio_attr[cnt].dev_attr.attr.name = > + iio_attr->address = ad7280a_devaddr(dev) << 8 | ch; > + iio_attr->dev_attr.attr.mode = 0644; > + iio_attr->dev_attr.show = ad7280_show_balance_sw; > + iio_attr->dev_attr.store = ad7280_store_balance_sw; > + iio_attr->dev_attr.attr.name = > devm_kasprintf(&st->spi->dev, GFP_KERNEL, > "in%d-in%d_balance_switch_en", > index, index + 1); > - ad7280_attributes[cnt] = > - &st->iio_attr[cnt].dev_attr.attr; > + if (!iio_attr->dev_attr.attr.name) > + return -ENOMEM; > + > + ad7280_attributes[cnt] = &iio_attr->dev_attr.attr; > cnt++; > - st->iio_attr[cnt].address = > - ad7280a_devaddr(dev) << 8 | > + iio_attr = &st->iio_attr[cnt]; > + iio_attr->address = ad7280a_devaddr(dev) << 8 | > (AD7280A_CB1_TIMER + ch); > - st->iio_attr[cnt].dev_attr.attr.mode = > - 0644; > - st->iio_attr[cnt].dev_attr.show = > - ad7280_show_balance_timer; > - st->iio_attr[cnt].dev_attr.store = > - ad7280_store_balance_timer; > - st->iio_attr[cnt].dev_attr.attr.name = > + iio_attr->dev_attr.attr.mode = 0644; > + iio_attr->dev_attr.show = ad7280_show_balance_timer; > + iio_attr->dev_attr.store = ad7280_store_balance_timer; > + iio_attr->dev_attr.attr.name = > devm_kasprintf(&st->spi->dev, GFP_KERNEL, > "in%d-in%d_balance_timer", > index, index + 1); > - ad7280_attributes[cnt] = > - &st->iio_attr[cnt].dev_attr.attr; > + if (!iio_attr->dev_attr.attr.name) > + return -ENOMEM; > + > + ad7280_attributes[cnt] = &iio_attr->dev_attr.attr; > } > > ad7280_attributes[cnt] = NULL;