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 1C086C2D0A3 for ; Mon, 9 Nov 2020 13:39:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C3B89206B2 for ; Mon, 9 Nov 2020 13:39:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604929171; bh=/y7H92Kxy/9wo+t0QSJYuIYPw2TgRjpkBGgOFB+T/No=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1iEqpNdxzBPKZ0eOtSlRrwh5BoDcSYwHNH9yuIqLxWqTeUKoTZXT8KicLRuaP1BoW QIrQ38+zIPhhVuyphBzRt97+SqpUn7U1HibrwLt8U4bkLw9t9SlgLeSKW3MyDgYcIs aXRmRwMRT1oOX87fOKSbC/J+SevdbJmzJ5oLHBlU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387734AbgKINja (ORCPT ); Mon, 9 Nov 2020 08:39:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:56244 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730670AbgKINDk (ORCPT ); Mon, 9 Nov 2020 08:03:40 -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 A480E22202; Mon, 9 Nov 2020 13:02:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604926977; bh=/y7H92Kxy/9wo+t0QSJYuIYPw2TgRjpkBGgOFB+T/No=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iu9o33Sx1m5JquLxP2nBc//Lj8AGQrEy+IpauGD3IOF2e0mJJTzDTqkjzKfdlQaFp 0slAdUIFZ0x+TLEyTopoLCS3N6/RZynLGe7rn3i7l7wT7LSQkptpI6y1CxeTunEQri WMXKe6ElMrbcJlI9MUTcsNHCj1qQI+UXptJlsSKg= 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 4.9 068/117] iio:gyro:itg3200: Fix timestamp alignment and prevent data leak. Date: Mon, 9 Nov 2020 13:54:54 +0100 Message-Id: <20201109125028.902266505@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201109125025.630721781@linuxfoundation.org> References: <20201109125025.630721781@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);