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=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 987ACC433F8 for ; Mon, 20 Jul 2020 16:36:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 79ED020734 for ; Mon, 20 Jul 2020 16:36:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595263018; bh=aaTkkjTThiK4kO48WcJTrCLmtM7O9Qdc/8N21SoD+Mk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=cRY9mj9UlkLKzqIt6LamsAnYH+ycuNUuWljz+VGnSDdEl5mTdPAiJuQAlRl+VZDY5 3k9jnAtC43Milv4eGvwt1lMcYgCfMWWP/uTIhLvzvck+3OSBwha/1xiqYaozGJmBBw oQn06JVdWAZ04nTuRKKRQ1Ct1nhtPzUft4bNzSUg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731338AbgGTQg5 (ORCPT ); Mon, 20 Jul 2020 12:36:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:49496 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731316AbgGTPwF (ORCPT ); Mon, 20 Jul 2020 11:52:05 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 4E8042064B; Mon, 20 Jul 2020 15:52:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595260324; bh=aaTkkjTThiK4kO48WcJTrCLmtM7O9Qdc/8N21SoD+Mk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z1Z3fRe4mlAyQ7nd5hLQZbNcQ8lcLQ6CQM44tp3A+BYtHG1IshtgFm+3eJwzsqmlA 7DMDy9orKXjiki51MYk6/csOdp8dctTydYbgyxTNj2xtCCFanOnveNl8nn2UFMB1Dy dYxqe75x9p0LS0cXJiVWDyc4sbJYonHiYmXLV1MM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars-Peter Clausen , Lorenzo Bianconi , Jonathan Cameron , Stable@vger.kernel.org Subject: [PATCH 4.19 034/133] iio:humidity:hts221 Fix alignment and data leak issues Date: Mon, 20 Jul 2020 17:36:21 +0200 Message-Id: <20200720152805.365344523@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200720152803.732195882@linuxfoundation.org> References: <20200720152803.732195882@linuxfoundation.org> User-Agent: quilt/0.66 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 From: Jonathan Cameron commit 5c49056ad9f3c786f7716da2dd47e4488fc6bd25 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() data. This data is allocated with kzalloc so no data can leak apart from previous readings. Explicit alignment of ts needed to ensure consistent padding on all architectures (particularly x86_32 with it's 4 byte alignment of s64) Fixes: e4a70e3e7d84 ("iio: humidity: add support to hts221 rh/temp combo device") Reported-by: Lars-Peter Clausen Acked-by: Lorenzo Bianconi Signed-off-by: Jonathan Cameron Cc: Signed-off-by: Greg Kroah-Hartman --- drivers/iio/humidity/hts221.h | 7 +++++-- drivers/iio/humidity/hts221_buffer.c | 9 +++++---- 2 files changed, 10 insertions(+), 6 deletions(-) --- a/drivers/iio/humidity/hts221.h +++ b/drivers/iio/humidity/hts221.h @@ -15,8 +15,6 @@ #include -#define HTS221_DATA_SIZE 2 - enum hts221_sensor_type { HTS221_SENSOR_H, HTS221_SENSOR_T, @@ -40,6 +38,11 @@ struct hts221_hw { bool enabled; u8 odr; + /* Ensure natural alignment of timestamp */ + struct { + __le16 channels[2]; + s64 ts __aligned(8); + } scan; }; extern const struct dev_pm_ops hts221_pm_ops; --- a/drivers/iio/humidity/hts221_buffer.c +++ b/drivers/iio/humidity/hts221_buffer.c @@ -163,7 +163,6 @@ static const struct iio_buffer_setup_ops static irqreturn_t hts221_buffer_handler_thread(int irq, void *p) { - u8 buffer[ALIGN(2 * HTS221_DATA_SIZE, sizeof(s64)) + sizeof(s64)]; struct iio_poll_func *pf = p; struct iio_dev *iio_dev = pf->indio_dev; struct hts221_hw *hw = iio_priv(iio_dev); @@ -173,18 +172,20 @@ static irqreturn_t hts221_buffer_handler /* humidity data */ ch = &iio_dev->channels[HTS221_SENSOR_H]; err = regmap_bulk_read(hw->regmap, ch->address, - buffer, HTS221_DATA_SIZE); + &hw->scan.channels[0], + sizeof(hw->scan.channels[0])); if (err < 0) goto out; /* temperature data */ ch = &iio_dev->channels[HTS221_SENSOR_T]; err = regmap_bulk_read(hw->regmap, ch->address, - buffer + HTS221_DATA_SIZE, HTS221_DATA_SIZE); + &hw->scan.channels[1], + sizeof(hw->scan.channels[1])); 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: