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 D3B9FC433E0 for ; Mon, 20 Jul 2020 15:41:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D0BB22CE3 for ; Mon, 20 Jul 2020 15:41:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595259695; bh=eVx2whG+iEhdi/wNAA8mHJvtFWijfFiSbn2YqjBTA2Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=AgiHWuxsJZIAdCvLtVEdEbfB9OLlUs08/IU67Reolajwyx/vROYQDBbTvKOrrgqtF Z14kf2k+EVejBkHcRpOGApFQNfro9bWUWGAShRid3uZ8LdqDZLA7HDRCCoeW7WWF+u TV0Cq0qqQs5f+O970fnVuuPe6v+Xxrkyc91Rg+mA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729917AbgGTPle (ORCPT ); Mon, 20 Jul 2020 11:41:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:33406 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729895AbgGTPla (ORCPT ); Mon, 20 Jul 2020 11:41:30 -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 066B322CF7; Mon, 20 Jul 2020 15:41:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595259689; bh=eVx2whG+iEhdi/wNAA8mHJvtFWijfFiSbn2YqjBTA2Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eosXuhfkhd9KI6B5CVtkAlxHOPYh3Bmuenz9MK785357xggTqwJksY9XRrmtn5nC8 OEb2fj+9S60BtMoQtjy7Q2KBgT7HCR315DoGIP5JvEygb5qTyMETgmWwtaKFqZuks0 +PMTVaLNxe5Jx4jLcl7gNixyM/HFDYzjinGxWCmo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars-Peter Clausen , Jonathan Cameron , Tomasz Duszynski , Stable@vger.kernel.org Subject: [PATCH 4.9 45/86] iio:pressure:ms5611 Fix buffer element alignment Date: Mon, 20 Jul 2020 17:36:41 +0200 Message-Id: <20200720152755.428091647@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200720152753.138974850@linuxfoundation.org> References: <20200720152753.138974850@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jonathan Cameron commit 8db4afe163bbdd93dca6fcefbb831ef12ecc6b4d 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. Here there is no data leak possibility so use an explicit structure on the stack to ensure alignment and nice readable fashion. The forced alignment of ts isn't strictly necessary in this driver as the padding will be correct anyway (there isn't any). However it is probably less fragile to have it there and it acts as documentation of the requirement. Fixes: 713bbb4efb9dc ("iio: pressure: ms5611: Add triggered buffer support") Reported-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Acked-by: Tomasz Duszynski Cc: Signed-off-by: Greg Kroah-Hartman --- drivers/iio/pressure/ms5611_core.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/drivers/iio/pressure/ms5611_core.c +++ b/drivers/iio/pressure/ms5611_core.c @@ -215,16 +215,21 @@ static irqreturn_t ms5611_trigger_handle struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct ms5611_state *st = iio_priv(indio_dev); - s32 buf[4]; /* s32 (pressure) + s32 (temp) + 2 * s32 (timestamp) */ + /* Ensure buffer elements are naturally aligned */ + struct { + s32 channels[2]; + s64 ts __aligned(8); + } scan; int ret; mutex_lock(&st->lock); - ret = ms5611_read_temp_and_pressure(indio_dev, &buf[1], &buf[0]); + ret = ms5611_read_temp_and_pressure(indio_dev, &scan.channels[1], + &scan.channels[0]); mutex_unlock(&st->lock); if (ret < 0) goto err; - iio_push_to_buffers_with_timestamp(indio_dev, buf, + iio_push_to_buffers_with_timestamp(indio_dev, &scan, iio_get_time_ns(indio_dev)); err: