From patchwork Tue Sep 15 14:13:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 305246 Delivered-To: patch@linaro.org Received: by 2002:a92:5ad1:0:0:0:0:0 with SMTP id b78csp2601365ilg; Tue, 15 Sep 2020 07:30:47 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzXZDqWLXkPR35ZRL4L6gdienNHLyUDdo/I00+/SUN1xNWYtrYbBysbGBfui9doL2oiTpKG X-Received: by 2002:a17:906:3552:: with SMTP id s18mr20193307eja.23.1600180247114; Tue, 15 Sep 2020 07:30:47 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1600180247; cv=none; d=google.com; s=arc-20160816; b=pA6SMg0TRWfEZHM/VNzei+s5E8iFGr6NEx+CSSqYunFjXSndTQVq4drLTmzDpWWuTz Gh7XdwgjdVi5ECDFODHgxfwcl9HcedOyi3vWUevb7/IryZSDKTej6yOScUezStd65OD5 pihynuAduij72vDE8c0smdHD4M2I5na0oWapCursBYU1/NE3ucOuDaNGmgaxRzyQwNUI IbC7uZx4hT+EsD5HzeEd3UGOpFfQvYWQMrzpP6g/6foH1ThOh4PPI0CQ6KHOxca948q8 QavSTbrCE99Jx1QysU54IQjIYDeGQ9uG7IwaRBuU/8N6LwFFK8vICHUfnrNO1//VuH/c Wdqw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=zk5lu4Sb0ykLk1QbdIsLOhODPlfTjWm1lZLfrG4TXaU=; b=nDaQ2J8MFdFzenjJe5v+g0W++SaInrz341UAFhqT2z09lcEsvdNZne5Vxnf9mz8x9U n++0WC+BChJBmtku6XTvBog164+0mDx2pPi/Eoagt6yUkOhEDySKHjFGZ2CxbUeczDI9 PVDfIdlPk4lYCow/fauDAmS/gcdhtLwUmhTg00XSFKzeG///vcJyAVCT9AhJZ9liGQax hfXqlPJXDlV/SvlLtjmGddmo8OAs+JphjJT06QOKmKtkdlT2/mFT0t7cyDGhgzaO+tYK YQn7YFMFR/bOSt+AbfkmTCzoEJAnRBFjOgihkjG4jEB0Q9D+m+coyflp3XrzWKiXIic2 AunA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=c+ttdepg; spf=pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id g1si9779746ejz.637.2020.09.15.07.30.46; Tue, 15 Sep 2020 07:30:47 -0700 (PDT) Received-SPF: pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=c+ttdepg; spf=pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727020AbgIOOa0 (ORCPT + 15 others); Tue, 15 Sep 2020 10:30:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:43012 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726986AbgIOO3B (ORCPT ); Tue, 15 Sep 2020 10:29:01 -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 4D2FB22A85; Tue, 15 Sep 2020 14:21:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600179691; bh=oPnzkviW5RFXpkvip4Qi0MFpC8KohykpXyGJM8vAqeQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c+ttdepg8aMz0wTG8SFSAby9f6UidHsYkZ2NKw0Ut56P5VTzXh6QHZkMKeyCMtgD/ T3iyHKW0hndHqNw4LpUlODGlrUIq1v/c7sE+hYT2fZQw8sNnj6YJExvJYlu1M1sxFp OI+1eVREMyGhyc1ku5wRdtSSNAepiZyO+AJ2agtY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars-Peter Clausen , =?utf-8?q?M=C3=A5rten_Lindahl?= , Jonathan Cameron , Andy Shevchenko , Stable@vger.kernel.org Subject: [PATCH 5.4 080/132] iio:adc:ti-adc084s021 Fix alignment and data leak issues. Date: Tue, 15 Sep 2020 16:13:02 +0200 Message-Id: <20200915140648.104960116@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200915140644.037604909@linuxfoundation.org> References: <20200915140644.037604909@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jonathan Cameron commit a661b571e3682705cb402a5cd1e970586a3ec00f upstream. 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: Signed-off-by: Greg Kroah-Hartman --- drivers/iio/adc/ti-adc084s021.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/drivers/iio/adc/ti-adc084s021.c +++ b/drivers/iio/adc/ti-adc084s021.c @@ -25,6 +25,11 @@ 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. @@ -140,14 +145,13 @@ static irqreturn_t adc084s021_buffer_tri 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);