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_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 2D382C433DF for ; Sun, 5 Jul 2020 11:48:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 059CB20739 for ; Sun, 5 Jul 2020 11:48:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593949692; bh=rDkLTaJ4VPckMkuuGjiXEY81pmUpquRpMHbD3nSCGTM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=cfAWtNyK87l72xO2zme7tF+sIE8moYiq3Lt03hPobdsUL9wi1UYI0c5FMSpZ9xu6v 28IiJVCF5rUMiFplRz1Wy+v1iIjYHzSOq76lqMmi7WPJcD58O3/voA5GYSJA0OgqSi lTG0biH62ehOvCsFSehe8CfLci8Rd+XIxbDyqddE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726692AbgGELsL (ORCPT ); Sun, 5 Jul 2020 07:48:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:55412 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726454AbgGELsL (ORCPT ); Sun, 5 Jul 2020 07:48:11 -0400 Received: from archlinux (cpc149474-cmbg20-2-0-cust94.5-4.cable.virginm.net [82.4.196.95]) (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 04DA920723; Sun, 5 Jul 2020 11:48:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593949690; bh=rDkLTaJ4VPckMkuuGjiXEY81pmUpquRpMHbD3nSCGTM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=oaffv0VNcwpQSN12ohP/DyMde4E3WdYy/lRV6x3rMym8TIeOgsUofecf3t7Qry4bh eig7rs4yKKDsVmgFsH9rtTqAqBDl+mwlG9Vos7ZGiH3YXeK9cn6meDdpPgzpOL4NRv ulZzleHrjB5klporJsZqfbC9HLDdc/5JLu0ECfSA= Date: Sun, 5 Jul 2020 12:48:07 +0100 From: Jonathan Cameron To: linux-iio@vger.kernel.org Cc: Andy Shevchenko , Jonathan Cameron , Lars-Peter Clausen , Lorenzo Bianconi Subject: Re: [PATCH 17/32] iio:humidity:hts221 Fix alignment and data leak issues Message-ID: <20200705124807.6fa6fd14@archlinux> In-Reply-To: <20200607155408.958437-18-jic23@kernel.org> References: <20200607155408.958437-1-jic23@kernel.org> <20200607155408.958437-18-jic23@kernel.org> X-Mailer: Claws Mail 3.17.5 (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-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Sun, 7 Jun 2020 16:53:53 +0100 Jonathan Cameron wrote: > From: Jonathan Cameron > > One of a class of bugs pointed out by Lars in a recent review. > iio_push_to_buffers_with_timestamp assumes the buffer used is aligned > to the size of the timestamp (8 bytes). This is not guaranteed in > this driver which uses an array of smaller elements on the stack. > As Lars also noted this anti pattern can involve a leak of data to > userspace and that indeed can happen here. We close both issues by > moving to a suitable structure in the iio_priv() data. > This data is allocated with kzalloc so no data can leak > apart from previous readings. > > Explicit alignment of ts needed to ensure consistent padding > on all architectures (particularly x86_32 with it's 4 byte alignment > of s64) > > Fixes: e4a70e3e7d84 ("iio: humidity: add support to hts221 rh/temp combo device") > Reported-by: Lars-Peter Clausen > Acked-by: Lorenzo Bianconi > Signed-off-by: Jonathan Cameron Applied to the fixes-togreg branch of iio.git and marked for stable. I'm scooping up all the ones in this series for which I have an ack so that we can focus on getting remainder reviewed. Thanks, Jonathan > --- > drivers/iio/humidity/hts221.h | 7 +++++-- > drivers/iio/humidity/hts221_buffer.c | 9 +++++---- > 2 files changed, 10 insertions(+), 6 deletions(-) > > diff --git a/drivers/iio/humidity/hts221.h b/drivers/iio/humidity/hts221.h > index 7c650df77556..721359e226cb 100644 > --- a/drivers/iio/humidity/hts221.h > +++ b/drivers/iio/humidity/hts221.h > @@ -14,8 +14,6 @@ > > #include > > -#define HTS221_DATA_SIZE 2 > - > enum hts221_sensor_type { > HTS221_SENSOR_H, > HTS221_SENSOR_T, > @@ -39,6 +37,11 @@ struct hts221_hw { > > bool enabled; > u8 odr; > + /* Ensure natural alignment of timestamp */ > + struct { > + __le16 channels[2]; > + s64 ts __aligned(8); > + } scan; > }; > > extern const struct dev_pm_ops hts221_pm_ops; > diff --git a/drivers/iio/humidity/hts221_buffer.c b/drivers/iio/humidity/hts221_buffer.c > index 21c6c160462d..59ede9860185 100644 > --- a/drivers/iio/humidity/hts221_buffer.c > +++ b/drivers/iio/humidity/hts221_buffer.c > @@ -160,7 +160,6 @@ static const struct iio_buffer_setup_ops hts221_buffer_ops = { > > static irqreturn_t hts221_buffer_handler_thread(int irq, void *p) > { > - u8 buffer[ALIGN(2 * HTS221_DATA_SIZE, sizeof(s64)) + sizeof(s64)]; > struct iio_poll_func *pf = p; > struct iio_dev *iio_dev = pf->indio_dev; > struct hts221_hw *hw = iio_priv(iio_dev); > @@ -170,18 +169,20 @@ static irqreturn_t hts221_buffer_handler_thread(int irq, void *p) > /* humidity data */ > ch = &iio_dev->channels[HTS221_SENSOR_H]; > err = regmap_bulk_read(hw->regmap, ch->address, > - buffer, HTS221_DATA_SIZE); > + &hw->scan.channels[0], > + sizeof(hw->scan.channels[0])); > if (err < 0) > goto out; > > /* temperature data */ > ch = &iio_dev->channels[HTS221_SENSOR_T]; > err = regmap_bulk_read(hw->regmap, ch->address, > - buffer + HTS221_DATA_SIZE, HTS221_DATA_SIZE); > + &hw->scan.channels[1], > + sizeof(hw->scan.channels[1])); > if (err < 0) > goto out; > > - iio_push_to_buffers_with_timestamp(iio_dev, buffer, > + iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan, > iio_get_time_ns(iio_dev)); > > out: