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=-15.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,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 62DA0C433E2 for ; Mon, 31 Aug 2020 10:26:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4397420EDD for ; Mon, 31 Aug 2020 10:26:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598869599; bh=kEkjp4+ErGVNxpJ1hO7V4ewqacRryuOsfHhAyrcTOEU=; h=Subject:To:From:Date:List-ID:From; b=GO8qfImFuhOSnNt/YegP/t5zQC56MLSZtibF3ax0MilZErUsd5IEigv6ZdbiYcOUz zDgKGbV0PHNikebX2M3SaH6JiKpq3srmekdiUuOgf+bMmiuafL3N0aCqu0Op2IcmU1 abagdHxp8aiCEHzsfymAKwExxgkTdISzx0eCP4FM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726512AbgHaK0i (ORCPT ); Mon, 31 Aug 2020 06:26:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:56402 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726472AbgHaK0i (ORCPT ); Mon, 31 Aug 2020 06:26:38 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 2A5A420DD4; Mon, 31 Aug 2020 10:26:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598869597; bh=kEkjp4+ErGVNxpJ1hO7V4ewqacRryuOsfHhAyrcTOEU=; h=Subject:To:From:Date:From; b=FbYQDWRweI6gUBBBZK8qSAvaf8aFr/ft8fEDzLORYVXCLWQ7XPWLDgc2hBmzIIIml KmmgTxh69orzs6TrF/o1e7dST3Hxj3+QVbqm0JHql9jahU2S5EtPJ5YtCSYAK+z108 qFD17feasjSqpghcqUag9NB4pcfPDtMl3bJkJBDQ= Subject: patch "iio:adc:ti-adc084s021 Fix alignment and data leak issues." added to staging-linus To: Jonathan.Cameron@huawei.com, Stable@vger.kernel.org, andy.shevchenko@gmail.com, lars@metafoo.de, martenli@axis.com From: Date: Mon, 31 Aug 2020 12:26:24 +0200 Message-ID: <159886958462116@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled iio:adc:ti-adc084s021 Fix alignment and data leak issues. to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From a661b571e3682705cb402a5cd1e970586a3ec00f Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Wed, 22 Jul 2020 16:50:57 +0100 Subject: iio:adc:ti-adc084s021 Fix alignment and data leak issues. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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(). This data is allocated with kzalloc so no data can leak apart from previous readings. The force alignment of ts is not strictly necessary in this case but reduces the fragility of the code. Fixes: 3691e5a69449 ("iio: adc: add driver for the ti-adc084s021 chip") Reported-by: Lars-Peter Clausen Cc: Mårten Lindahl Signed-off-by: Jonathan Cameron Reviewed-by: Andy Shevchenko Cc: --- drivers/iio/adc/ti-adc084s021.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/iio/adc/ti-adc084s021.c b/drivers/iio/adc/ti-adc084s021.c index 9017e1e24273..dfba34834a57 100644 --- a/drivers/iio/adc/ti-adc084s021.c +++ b/drivers/iio/adc/ti-adc084s021.c @@ -26,6 +26,11 @@ struct adc084s021 { struct spi_transfer spi_trans; struct regulator *reg; struct mutex lock; + /* Buffer used to align data */ + struct { + __be16 channels[4]; + s64 ts __aligned(8); + } scan; /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache line. @@ -141,14 +146,13 @@ static irqreturn_t adc084s021_buffer_trigger_handler(int irq, void *pollfunc) struct iio_poll_func *pf = pollfunc; struct iio_dev *indio_dev = pf->indio_dev; struct adc084s021 *adc = iio_priv(indio_dev); - __be16 data[8] = {0}; /* 4 * 16-bit words of data + 8 bytes timestamp */ mutex_lock(&adc->lock); - if (adc084s021_adc_conversion(adc, &data) < 0) + if (adc084s021_adc_conversion(adc, adc->scan.channels) < 0) dev_err(&adc->spi->dev, "Failed to read data\n"); - iio_push_to_buffers_with_timestamp(indio_dev, data, + iio_push_to_buffers_with_timestamp(indio_dev, &adc->scan, iio_get_time_ns(indio_dev)); mutex_unlock(&adc->lock); iio_trigger_notify_done(indio_dev->trig); -- 2.28.0