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 89EE9C433E0 for ; Sun, 5 Jul 2020 11:42:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 58CA720739 for ; Sun, 5 Jul 2020 11:42:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593949332; bh=M5lEzul0LZKkMuAjrm9xknPvHKG1Xnnpk4YILGpJdyY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=xMJxcpAKowZgiCUwUZnSgmJCLesbGFIfYT2vvBnCqDupI4rx5Sjf6DqIJxc5afqoy dYeKSbd1hE2XvHlgEAzFW60/YmQvDzXe+LVy3rC2WZE0ZjaZHuiUqC42AxaU1AGR/P sDjT6nlvCdVWysse0lPIAOvJl8+oWX/HXR95wpgY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726480AbgGELmL (ORCPT ); Sun, 5 Jul 2020 07:42:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:54290 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726454AbgGELmL (ORCPT ); Sun, 5 Jul 2020 07:42:11 -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 193F220723; Sun, 5 Jul 2020 11:42:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593949331; bh=M5lEzul0LZKkMuAjrm9xknPvHKG1Xnnpk4YILGpJdyY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=fa3JuskL8doZgWAjrB6Pdr1KDhmYjPh4Eeezve5p4fbRTEejdQPwKGUaAZkvfyqNL hHSp2aQ5GOY8sZ9HDQo9zH4rEjuKn86cu25MryIt+RjfFflt8uMMcqXAdx+40pSbXP 66i4q/xV8dSYXWhynMwjDyrK8AAov3+135hCu3vk= Date: Sun, 5 Jul 2020 12:42:06 +0100 From: Jonathan Cameron To: linux-iio@vger.kernel.org Cc: Andy Shevchenko , Jonathan Cameron , Lars-Peter Clausen , Lorenzo Bianconi Subject: Re: [PATCH 11/32] iio:light:st_uvis25 Fix timestamp alignment and prevent data leak. Message-ID: <20200705124206.05b46693@archlinux> In-Reply-To: <20200607155408.958437-12-jic23@kernel.org> References: <20200607155408.958437-1-jic23@kernel.org> <20200607155408.958437-12-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 16:53:47 +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() > > This data is allocated with kzalloc so no data can leak apart > from previous readings. > > Fixes: 3025c8688c1e ("iio: light: add support for UVIS25 sensor") > 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 going to pick up all the ones in this series that I have had an Ack for. Thanks, Jonathan > --- > drivers/iio/light/st_uvis25.h | 5 +++++ > drivers/iio/light/st_uvis25_core.c | 6 +++--- > 2 files changed, 8 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/light/st_uvis25.h b/drivers/iio/light/st_uvis25.h > index 78bc56aad129..283086887caf 100644 > --- 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; > diff --git a/drivers/iio/light/st_uvis25_core.c b/drivers/iio/light/st_uvis25_core.c > index 4d001d50e775..818b8faea73c 100644 > --- a/drivers/iio/light/st_uvis25_core.c > +++ b/drivers/iio/light/st_uvis25_core.c > @@ -234,17 +234,17 @@ static const struct iio_buffer_setup_ops st_uvis25_buffer_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); > int err; > > - err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, (int *)buffer); > + err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, > + (unsigned int *)&hw->scan.chan); > 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: