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=-11.6 required=3.0 tests=BAYES_00,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 5DBF0C433DF for ; Sun, 9 Aug 2020 17:27:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3AF8E206CD for ; Sun, 9 Aug 2020 17:27:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596994055; bh=0qi68VaL/NPvlVeSfairC7cMSgFjOoFfDTjEvbDCT8E=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=Gy8Qc93FC7R+MEplQ/Oz48rF95nJQ5h4hqvpba324Tl2yruG205ZFrTe9bFsXgKh0 WGMorx5FaxgUk7006VfeihcygeMZGJDIGtUCbDKpORvpn/2BxjJEhXU0gO7eal14GL zXZlL8S5ovvr3vWRGeaZ3uhuePpBI0HMmJ1cubV0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726229AbgHIR1e (ORCPT ); Sun, 9 Aug 2020 13:27:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:56020 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726234AbgHIR1e (ORCPT ); Sun, 9 Aug 2020 13:27:34 -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 C41FD206C3; Sun, 9 Aug 2020 17:27:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596994053; bh=0qi68VaL/NPvlVeSfairC7cMSgFjOoFfDTjEvbDCT8E=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=tKdWU8CnLWlAesyYew/ui9TzZC5eUIozBv3XJTI2cOqKBy7shTH4edSmfrVOizA8x qzTRL8PJhkF8KIdEteIYc+eQ5qkYVOuHRV6Fa+850liO/cIinIjQ2AWO7linY+SWvc BlZZR/MxfHhrE324mJx3geNy/wHmIe86wperQUGk= Date: Sun, 9 Aug 2020 18:27:30 +0100 From: Jonathan Cameron To: linux-iio@vger.kernel.org Cc: Andy Shevchenko , Lars-Peter Clausen , Peter Meerwald , Jonathan Cameron Subject: Re: [PATCH v3 12/27] iio:light:ltr501 Fix timestamp alignment issue. Message-ID: <20200809182730.638a032c@archlinux> In-Reply-To: <20200722155103.979802-13-jic23@kernel.org> References: <20200722155103.979802-1-jic23@kernel.org> <20200722155103.979802-13-jic23@kernel.org> X-Mailer: Claws Mail 3.17.6 (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 Wed, 22 Jul 2020 16:50:48 +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. > Here we use a structure on the stack. The driver already did an > explicit memset so no data leak was possible. > > Forced alignment of ts is not strictly necessary but probably makes > the code slightly less fragile. > > Note there has been some rework in this driver of the years, so no > way this will apply cleanly all the way back. > > Fixes: 2690be905123 ("iio: Add Lite-On ltr501 ambient light / proximity sensor driver") > Reported-by: Lars-Peter Clausen > Signed-off-by: Jonathan Cameron Applied and marked for stable. Thanks, Jonathan > --- > drivers/iio/light/ltr501.c | 15 +++++++++------ > 1 file changed, 9 insertions(+), 6 deletions(-) > > diff --git a/drivers/iio/light/ltr501.c b/drivers/iio/light/ltr501.c > index 4bac0646398d..b4323d2db0b1 100644 > --- a/drivers/iio/light/ltr501.c > +++ b/drivers/iio/light/ltr501.c > @@ -1243,13 +1243,16 @@ static irqreturn_t ltr501_trigger_handler(int irq, void *p) > struct iio_poll_func *pf = p; > struct iio_dev *indio_dev = pf->indio_dev; > struct ltr501_data *data = iio_priv(indio_dev); > - u16 buf[8]; > + struct { > + u16 channels[3]; > + s64 ts __aligned(8); > + } scan; > __le16 als_buf[2]; > u8 mask = 0; > int j = 0; > int ret, psdata; > > - memset(buf, 0, sizeof(buf)); > + memset(&scan, 0, sizeof(scan)); > > /* figure out which data needs to be ready */ > if (test_bit(0, indio_dev->active_scan_mask) || > @@ -1268,9 +1271,9 @@ static irqreturn_t ltr501_trigger_handler(int irq, void *p) > if (ret < 0) > return ret; > if (test_bit(0, indio_dev->active_scan_mask)) > - buf[j++] = le16_to_cpu(als_buf[1]); > + scan.channels[j++] = le16_to_cpu(als_buf[1]); > if (test_bit(1, indio_dev->active_scan_mask)) > - buf[j++] = le16_to_cpu(als_buf[0]); > + scan.channels[j++] = le16_to_cpu(als_buf[0]); > } > > if (mask & LTR501_STATUS_PS_RDY) { > @@ -1278,10 +1281,10 @@ static irqreturn_t ltr501_trigger_handler(int irq, void *p) > &psdata, 2); > if (ret < 0) > goto done; > - buf[j++] = psdata & LTR501_PS_DATA_MASK; > + scan.channels[j++] = psdata & LTR501_PS_DATA_MASK; > } > > - iio_push_to_buffers_with_timestamp(indio_dev, buf, > + iio_push_to_buffers_with_timestamp(indio_dev, &scan, > iio_get_time_ns(indio_dev)); > > done: