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=-9.8 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=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 6CC5FC4741F for ; Mon, 9 Nov 2020 12:58:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0E94B216C4 for ; Mon, 9 Nov 2020 12:58:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604926731; bh=/y7H92Kxy/9wo+t0QSJYuIYPw2TgRjpkBGgOFB+T/No=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Tt9caNQeR7mylq9XAum1HAzISx+SqyuLK9LGR9gEbkM8Rudf3POgOqaGwdkyjSQaC uhUyR9wZbEbyICLBDohF+PX2bfJCp3bnRS9qQIsLh7quwwS2IH9q0w5EiBD6bfwmnI Fg6Os5hLx37FpZlZ3p2YamPOEb19Vb2oKnAF3RuE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730191AbgKIM6u (ORCPT ); Mon, 9 Nov 2020 07:58:50 -0500 Received: from mail.kernel.org ([198.145.29.99]:52748 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729984AbgKIM60 (ORCPT ); Mon, 9 Nov 2020 07:58:26 -0500 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 DDFA92076E; Mon, 9 Nov 2020 12:58:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604926705; bh=/y7H92Kxy/9wo+t0QSJYuIYPw2TgRjpkBGgOFB+T/No=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hCMeAK/1zV4sDYeKttvLpJEkeAEarrbmwhG/6lgg+zmFnsofXeuIdfN2A+X9LRz2z WQm5cMzWumQUh/PpxBZDngXJWDKZ+NSX4f6itl2fSpJVw7Pmd6OoiHj5vHgyph76mG jNtfNLpPEYVTbYN6KcmDzQRL3BqpwhGOKfG7tngA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars-Peter Clausen , Jonathan Cameron , Andy Shevchenko , Stable@vger.kernel.org Subject: [PATCH 4.4 45/86] iio:gyro:itg3200: Fix timestamp alignment and prevent data leak. Date: Mon, 9 Nov 2020 13:54:52 +0100 Message-Id: <20201109125023.004403488@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201109125020.852643676@linuxfoundation.org> References: <20201109125020.852643676@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jonathan Cameron commit 10ab7cfd5522f0041028556dac864a003e158556 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 a 16 byte array of smaller elements on the stack. This is fixed by using an explicit c structure. As there are no holes in the structure, there is no possiblity of data leakage in this case. The explicit alignment of ts is not strictly necessary but potentially makes the code slightly less fragile. It also removes the possibility of this being cut and paste into another driver where the alignment isn't already true. Fixes: 36e0371e7764 ("iio:itg3200: Use iio_push_to_buffers_with_timestamp()") Reported-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Reviewed-by: Andy Shevchenko Cc: Link: https://lore.kernel.org/r/20200722155103.979802-6-jic23@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/iio/gyro/itg3200_buffer.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) --- a/drivers/iio/gyro/itg3200_buffer.c +++ b/drivers/iio/gyro/itg3200_buffer.c @@ -49,13 +49,20 @@ static irqreturn_t itg3200_trigger_handl struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct itg3200 *st = iio_priv(indio_dev); - __be16 buf[ITG3200_SCAN_ELEMENTS + sizeof(s64)/sizeof(u16)]; + /* + * Ensure correct alignment and padding including for the + * timestamp that may be inserted. + */ + struct { + __be16 buf[ITG3200_SCAN_ELEMENTS]; + s64 ts __aligned(8); + } scan; - int ret = itg3200_read_all_channels(st->i2c, buf); + int ret = itg3200_read_all_channels(st->i2c, scan.buf); if (ret < 0) goto error_ret; - iio_push_to_buffers_with_timestamp(indio_dev, buf, pf->timestamp); + iio_push_to_buffers_with_timestamp(indio_dev, &scan, pf->timestamp); iio_trigger_notify_done(indio_dev->trig);