From patchwork Mon Sep 21 16:27:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 309464 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=-11.2 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 25D00C43466 for ; Mon, 21 Sep 2020 16:39:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E7486239D0 for ; Mon, 21 Sep 2020 16:39:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600706355; bh=IH0cmUkucraMa7ZS6OE8DP3p+0nMrO0v2OW9fXrewkE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=q4ZcTxt9DTq7z1T6WsWQpsopTIdQxX/l53dUL0iNI4iujVtUCrHFP37d2jnbNUQi0 mL9QYou04npCnMs/a4vOGEp9caWe1jMRMClpzNBPFgOBKCbg0Zr3yZ/a4xx1633XL+ qpFVZogVjcCkyRBVXkxM+Sqhp+uP7RHF8v6dmDb0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728706AbgIUQjP (ORCPT ); Mon, 21 Sep 2020 12:39:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:40146 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728396AbgIUQit (ORCPT ); Mon, 21 Sep 2020 12:38:49 -0400 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 037A623998; Mon, 21 Sep 2020 16:38:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600706329; bh=IH0cmUkucraMa7ZS6OE8DP3p+0nMrO0v2OW9fXrewkE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gnlDyH6mo6FRF4vNvAUJPwe2cEVi1YFX03pXaf+xoZOYKo6nAPAitkrBrCFQh7BC9 I4gdZOk2zuUzdHUQxY5JmNkwRRqUSWcE2u1GmK7oVvxX0ndjJ0Creot5LhqZzK69Aj JsVdkA0ynLiilW3pPBXUmiOwXyvIgAy3IVhzJEn4= 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 4.14 26/94] iio:light:ltr501 Fix timestamp alignment issue. Date: Mon, 21 Sep 2020 18:27:13 +0200 Message-Id: <20200921162036.755522960@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200921162035.541285330@linuxfoundation.org> References: <20200921162035.541285330@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jonathan Cameron commit 2684d5003490df5398aeafe2592ba9d4a4653998 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 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 Reviewed-by: Andy Shevchenko Cc: Signed-off-by: Greg Kroah-Hartman --- drivers/iio/light/ltr501.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) --- a/drivers/iio/light/ltr501.c +++ b/drivers/iio/light/ltr501.c @@ -1249,13 +1249,16 @@ static irqreturn_t ltr501_trigger_handle 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) || @@ -1274,9 +1277,9 @@ static irqreturn_t ltr501_trigger_handle 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) { @@ -1284,10 +1287,10 @@ static irqreturn_t ltr501_trigger_handle &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: