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=-13.1 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_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 61FF4C433F1 for ; Wed, 22 Jul 2020 15:53:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3C02D20B1F for ; Wed, 22 Jul 2020 15:53:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595433207; bh=9/Nc7AOxF+tbHgakEOl8OJWkFEiVTOk+Wrzfl1AmJXY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=v0LnMLhxskAT+4zQzqyh2d0syB911o47MRnYQtr4PVbdYnF9Mh9HQfW+sZK2WVAp9 vI0oKU90HHsZywlfIEE8FSR+2XMYbeOOwyG4lGZj7+3GDRhMKzhL4shJfxoDCZdq2Z GPWbcHCQozmBw9/CnBhOQnXnFso2NSvyWnPP35ZE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729249AbgGVPx0 (ORCPT ); Wed, 22 Jul 2020 11:53:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:35684 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726427AbgGVPx0 (ORCPT ); Wed, 22 Jul 2020 11:53:26 -0400 Received: from localhost.localdomain (cpc149474-cmbg20-2-0-cust94.5-4.cable.virginm.net [82.4.196.95]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4CBFC208E4; Wed, 22 Jul 2020 15:53:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595433206; bh=9/Nc7AOxF+tbHgakEOl8OJWkFEiVTOk+Wrzfl1AmJXY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JkXUXWygPfDnAdR3j742J3Qgzon7UggDjimF0s7zJ3u+bbBNTXKCd75He5NDjj+aM tUuOqIUmhEI3OE+onN4+SUvyubyIP64/oh5+J5GfPCrqKJ1Kln4+cuNpxobvA28u76 TfMdfJTYisCTFq4HmhIHk29vpWZQUAIyE62Qq5Os= From: Jonathan Cameron To: linux-iio@vger.kernel.org Cc: Andy Shevchenko , Lars-Peter Clausen , Peter Meerwald , Jonathan Cameron Subject: [PATCH v3 12/27] iio:light:ltr501 Fix timestamp alignment issue. Date: Wed, 22 Jul 2020 16:50:48 +0100 Message-Id: <20200722155103.979802-13-jic23@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200722155103.979802-1-jic23@kernel.org> References: <20200722155103.979802-1-jic23@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org 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 --- 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: -- 2.27.0