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 B75B2C433E6 for ; Mon, 31 Aug 2020 10:26:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 90B1D2100A for ; Mon, 31 Aug 2020 10:26:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598869587; bh=GR8lNoTv3ldNk13N3p1mgx//5pMLOrTx3AnDuKcI6UQ=; h=Subject:To:From:Date:List-ID:From; b=ZabJTR8p2b6oX/tRraRuYPrxH1qzQfAqvaT+Gro13ttVLBvnOWD1Zir1qjlZwquUc whnDpT+VZs/zsLo6atJx7qdF8dWupsjvScXCYYGdoisFW/mPJpGiOXcWWXJe3bWZrR 21fmE0PNbovPoKLjUehAw9DCDHkePBxB6uyPrZWQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726489AbgHaK01 (ORCPT ); Mon, 31 Aug 2020 06:26:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:55618 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726472AbgHaK00 (ORCPT ); Mon, 31 Aug 2020 06:26:26 -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 37F752145D; Mon, 31 Aug 2020 10:26:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598869585; bh=GR8lNoTv3ldNk13N3p1mgx//5pMLOrTx3AnDuKcI6UQ=; h=Subject:To:From:Date:From; b=1Qn/wG/oiR9bR16bwFmzV9d0fvmzooVxS/6xMStzURWP7S10dIoGwyY2fvNcJHTdo 98Cnwz8ID9iqCcIAPHEKu1MJSU/u4FV2BJjeZZzmDVPFRWDtaV7FxNARVDkyjAGlBJ NFPqgWuq/E+qOQrFYNRWhqazPdZnu18nTGWWxGwM= Subject: patch "iio:chemical:ccs811: Fix timestamp alignment and prevent data leak." added to staging-linus To: Jonathan.Cameron@huawei.com, Stable@vger.kernel.org, andy.shevchenko@gmail.com, lars@metafoo.de, narcisaanamaria12@gmail.com From: Date: Mon, 31 Aug 2020 12:26:19 +0200 Message-ID: <159886957974126@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 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:chemical:ccs811: Fix timestamp alignment and prevent data leak. 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 eb1a148ef41d8ae8d9201efc3f1b145976290331 Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Wed, 22 Jul 2020 16:50:43 +0100 Subject: iio:chemical:ccs811: Fix timestamp alignment and prevent data leak. 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 with alignment explicitly requested. This data is allocated with kzalloc so no data can leak appart from previous readings. The explicit alignment of ts is necessary to ensure consistent padding for x86_32 in which the ts would otherwise be 4 byte aligned. Fixes: 283d26917ad6 ("iio: chemical: ccs811: Add triggered buffer support") Reported-by: Lars-Peter Clausen Cc: Narcisa Ana Maria Vasile Signed-off-by: Jonathan Cameron Reviewed-by: Andy Shevchenko Cc: --- drivers/iio/chemical/ccs811.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/iio/chemical/ccs811.c b/drivers/iio/chemical/ccs811.c index 2b007e7568b2..60dd87e96f5f 100644 --- a/drivers/iio/chemical/ccs811.c +++ b/drivers/iio/chemical/ccs811.c @@ -78,6 +78,11 @@ struct ccs811_data { struct iio_trigger *drdy_trig; struct gpio_desc *wakeup_gpio; bool drdy_trig_on; + /* Ensures correct alignment of timestamp if present */ + struct { + s16 channels[2]; + s64 ts __aligned(8); + } scan; }; static const struct iio_chan_spec ccs811_channels[] = { @@ -327,17 +332,17 @@ static irqreturn_t ccs811_trigger_handler(int irq, void *p) struct iio_dev *indio_dev = pf->indio_dev; struct ccs811_data *data = iio_priv(indio_dev); struct i2c_client *client = data->client; - s16 buf[8]; /* s16 eCO2 + s16 TVOC + padding + 8 byte timestamp */ int ret; - ret = i2c_smbus_read_i2c_block_data(client, CCS811_ALG_RESULT_DATA, 4, - (u8 *)&buf); + ret = i2c_smbus_read_i2c_block_data(client, CCS811_ALG_RESULT_DATA, + sizeof(data->scan.channels), + (u8 *)data->scan.channels); if (ret != 4) { dev_err(&client->dev, "cannot read sensor data\n"); goto err; } - iio_push_to_buffers_with_timestamp(indio_dev, buf, + iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, iio_get_time_ns(indio_dev)); err: -- 2.28.0