From patchwork Mon Dec 28 12:51:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 352718 Delivered-To: patch@linaro.org Received: by 2002:a02:85a7:0:0:0:0:0 with SMTP id d36csp9829284jai; Mon, 28 Dec 2020 07:27:12 -0800 (PST) X-Google-Smtp-Source: ABdhPJz6HG3EJ4X18eMCRvebzpXsYkMlktOjbvvmnjHrope/msMguiaASncvodO8oLirM7MEb8FX X-Received: by 2002:a50:d88c:: with SMTP id p12mr42616052edj.370.1609169232396; Mon, 28 Dec 2020 07:27:12 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1609169232; cv=none; d=google.com; s=arc-20160816; b=dJK+5pwzYlHBZssfpNmsfIauImSrBRa4kCNZPVCbkgdD2HGXfkMsvY7OLAAf2SprN1 znm0VnVyYS5zNPI6KOpzG4aMlC14yKR0hdPPK/6NUyAySgroXzQfwj6SnSvLqQNwWOp9 c68L4pq7DOACpQrEo+XlrJcwNLFcCrQPV1PcTFq/VobX3S5UEXUF5/vUf6MSF3o/qjv0 STmVfagkfA8g7vOhaWC2aPBu5LLed2HJ/xvrDw4T7OTBMOM3vLJzxLD+hQm6ElRlTYKi RoArRYg7A5a7E/3OTKVFndLw9UGS3KaoR288fLuWbCpKToycRgKIvcOhuRXL8B1H0vgR o0tg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=ppquJ+CTzZvJZPBLHIhUeA+KcC3b2DK/8ML3sbThoPs=; b=ojzRUXyWHtU2rSbcbOx7nD9Z0G8NetqLuINUuaJmghlJTv7TP6kWyys2JV+V7D11Cl 4Z2crDS8nBmmfzURBiDHsKqzZmNItOg6iChiT9mMSA7d4VUTcGv15XJeRLtOQHvn1xCC VP2qhk2R2Ue0HVCRH6fngDaUEzlluW4v7ljtvjujmC+kZrGvvthnMZK9qCOcLD/pkHMy 964i3f3Qg8xo3kEipKtP8ruoBBZq6uM61U7b/CvZq1FVvUz8Ae4zW9pdW6DP8kj7v1o9 z1Z4CoFDvv7+k015qr5OAD2mmEd1xJ9mY+m+rIld062+11kMliTxYxfl56LwFBvEYmiu OqNg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=iGoH7lOb; 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=pass (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 q11si20313189edn.225.2020.12.28.07.27.12; Mon, 28 Dec 2020 07:27:12 -0800 (PST) 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=@linuxfoundation.org header.s=korg header.b=iGoH7lOb; 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=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388914AbgL1P02 (ORCPT + 14 others); Mon, 28 Dec 2020 10:26:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:59100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406757AbgL1N5l (ORCPT ); Mon, 28 Dec 2020 08:57:41 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 530A620715; Mon, 28 Dec 2020 13:57:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609163846; bh=eiEb4v32L2uoSf4D9Ckw2K3GFDvoiZxEF34F7X0ZZls=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iGoH7lObA0roH5FaNHWcBtipg9ml33YWCyAv3p91fWMmJHpp1HNM+gzjEa6cu1+rL wnEU20/tsVA8GTwrZL3XjdyNxgmvlYGBDCdwni0DUkR1CuQexIlRBQ9xlew0KxDhF1 79eKmEALLMUgT49FJNtrOAmMgtQB9V0O1fj3KKqY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars-Peter Clausen , Jonathan Cameron , Alexandru Ardelean , Lorenzo Bianconi , Stable@vger.kernel.org Subject: [PATCH 5.4 428/453] iio:light:st_uvis25: Fix timestamp alignment and prevent data leak. Date: Mon, 28 Dec 2020 13:51:04 +0100 Message-Id: <20201228124957.817520045@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228124937.240114599@linuxfoundation.org> References: <20201228124937.240114599@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jonathan Cameron commit d837a996f57c29a985177bc03b0e599082047f27 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. A local unsigned int variable is used for the regmap call so it is clear there is no potential issue with writing into the padding of the structure. Fixes: 3025c8688c1e ("iio: light: add support for UVIS25 sensor") Reported-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Reviewed-by: Alexandru Ardelean Acked-by: Lorenzo Bianconi Cc: Link: https://lore.kernel.org/r/20200920112742.170751-3-jic23@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/iio/light/st_uvis25.h | 5 +++++ drivers/iio/light/st_uvis25_core.c | 8 +++++--- 2 files changed, 10 insertions(+), 3 deletions(-) --- a/drivers/iio/light/st_uvis25.h +++ b/drivers/iio/light/st_uvis25.h @@ -27,6 +27,11 @@ struct st_uvis25_hw { struct iio_trigger *trig; bool enabled; int irq; + /* Ensure timestamp is naturally aligned */ + struct { + u8 chan; + s64 ts __aligned(8); + } scan; }; extern const struct dev_pm_ops st_uvis25_pm_ops; --- a/drivers/iio/light/st_uvis25_core.c +++ b/drivers/iio/light/st_uvis25_core.c @@ -234,17 +234,19 @@ static const struct iio_buffer_setup_ops static irqreturn_t st_uvis25_buffer_handler_thread(int irq, void *p) { - u8 buffer[ALIGN(sizeof(u8), sizeof(s64)) + sizeof(s64)]; struct iio_poll_func *pf = p; struct iio_dev *iio_dev = pf->indio_dev; struct st_uvis25_hw *hw = iio_priv(iio_dev); + unsigned int val; int err; - err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, (int *)buffer); + err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, &val); if (err < 0) goto out; - iio_push_to_buffers_with_timestamp(iio_dev, buffer, + hw->scan.chan = val; + + iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan, iio_get_time_ns(iio_dev)); out: