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=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 C0162C07E95 for ; Sat, 10 Jul 2021 23:54:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A9E0061360 for ; Sat, 10 Jul 2021 23:54:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232405AbhGJX5B (ORCPT ); Sat, 10 Jul 2021 19:57:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:41100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233620AbhGJXz2 (ORCPT ); Sat, 10 Jul 2021 19:55:28 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6F9C761361; Sat, 10 Jul 2021 23:51:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625961113; bh=MTJeUlT1lX8Q2QZGFI5Y6L8wg5Q1jv17ASVH9xIfZEg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZK/dTIeeWvsvNwYrd1M40DCAix/qdrV7FYavw4BVx9miFQf3qZ53lU7Vm7f8eSe2V 8PYjo9RQoYxrfXU53tYqcZRLMCYSb/JXruHP1cw/8r6tPE4khRLc+bXpzSe8ftnft9 McMJeUXKVHQ2nxRKIu/8G7/vvQXqgeLtil4mXEn2gWueZbYgo8/sCLtxoBZuCovpEn 9uyBkVaryUh2Mz2GTla4W4VRNO/fX33wBrSf1Spw7iqq34vQp4Ic8FMceJ5suCT7Hd cEG38W5T5LHv/uFUdMtODkkOp9O0WeYPBVpGofRzeglpeiy+ZdplvGmdC/bqt+tK7q q9Mazx0nQ/fuQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zou Wei , Hulk Robot , Guenter Roeck , Wim Van Sebroeck , Sasha Levin , linux-watchdog@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 07/22] watchdog: sc520_wdt: Fix possible use-after-free in wdt_turnoff() Date: Sat, 10 Jul 2021 19:51:28 -0400 Message-Id: <20210710235143.3222129-7-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210710235143.3222129-1-sashal@kernel.org> References: <20210710235143.3222129-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Zou Wei [ Upstream commit 90b7c141132244e8e49a34a4c1e445cce33e07f4 ] This module's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself. Reported-by: Hulk Robot Signed-off-by: Zou Wei Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/1620716691-108460-1-git-send-email-zou_wei@huawei.com Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck Signed-off-by: Sasha Levin --- drivers/watchdog/sc520_wdt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/watchdog/sc520_wdt.c b/drivers/watchdog/sc520_wdt.c index 6aadb56e7faa..809ebcaef51d 100644 --- a/drivers/watchdog/sc520_wdt.c +++ b/drivers/watchdog/sc520_wdt.c @@ -190,7 +190,7 @@ static int wdt_startup(void) static int wdt_turnoff(void) { /* Stop the timer */ - del_timer(&timer); + del_timer_sync(&timer); /* Stop the watchdog */ wdt_config(0); -- 2.30.2