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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_SANE_1 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 5E932C432C0 for ; Mon, 2 Dec 2019 11:16:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2EA4B2084F for ; Mon, 2 Dec 2019 11:16:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727433AbfLBLQ0 (ORCPT ); Mon, 2 Dec 2019 06:16:26 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:60946 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726276AbfLBLQ0 (ORCPT ); Mon, 2 Dec 2019 06:16:26 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: eballetbo) with ESMTPSA id 6522E28DB10 Subject: Re: [PATCH] platform/chrome: wilco_ec: fix use after free issue To: Wen Yang , Benson Leung Cc: xlpang@linux.alibaba.com, Nick Crews , linux-kernel@vger.kernel.org References: <20191130130842.33763-1-wenyang@linux.alibaba.com> From: Enric Balletbo i Serra Message-ID: <5d19df91-ac9a-05a5-3636-c5f1594138a3@collabora.com> Date: Mon, 2 Dec 2019 12:16:21 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20191130130842.33763-1-wenyang@linux.alibaba.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Wen, On 30/11/19 14:08, Wen Yang wrote: > This is caused by dereferencing 'dev_data' after put_device() in > the telem_device_remove() function. > This patch just moves the put_device() down a bit to avoid this > issue. > > Fixes: 1210d1e6bad1 ("platform/chrome: wilco_ec: Add telemetry char device interface") > Signed-off-by: Wen Yang > Cc: Benson Leung > Cc: Enric Balletbo i Serra > Cc: Nick Crews > Cc: linux-kernel@vger.kernel.org > --- Queued for 5.5 as is a fix. Thanks. Enric > drivers/platform/chrome/wilco_ec/telemetry.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/platform/chrome/wilco_ec/telemetry.c b/drivers/platform/chrome/wilco_ec/telemetry.c > index b9d03c3..1176d54 100644 > --- a/drivers/platform/chrome/wilco_ec/telemetry.c > +++ b/drivers/platform/chrome/wilco_ec/telemetry.c > @@ -406,8 +406,8 @@ static int telem_device_remove(struct platform_device *pdev) > struct telem_device_data *dev_data = platform_get_drvdata(pdev); > > cdev_device_del(&dev_data->cdev, &dev_data->dev); > - put_device(&dev_data->dev); > ida_simple_remove(&telem_ida, MINOR(dev_data->dev.devt)); > + put_device(&dev_data->dev); > > return 0; > } >