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=-19.4 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,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 86BCBC11F6A for ; Sat, 10 Jul 2021 23:49:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E42F610A2 for ; Sat, 10 Jul 2021 23:49:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232762AbhGJXwk (ORCPT ); Sat, 10 Jul 2021 19:52:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:39238 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232566AbhGJXw0 (ORCPT ); Sat, 10 Jul 2021 19:52:26 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id F3A6D61356; Sat, 10 Jul 2021 23:49:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625960980; bh=xWCCHaF5NQH3bwlPXq7cZGPq7DcVswBFm6vzcPVvN44=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mWgUY7i1s91KbKVaEbPNvcnuN1IGvil/eOkNQ3s9MjG/82WfAyHL4WDH/b1KK4MtQ qIy0mw8GT4qXrWefmzyO53EVKmI+MFbkShVwOxLU8nDIz42NmX/K/iSGRvtu0coxSx KQY8lhruMq5TjFDpH5pRcfPeDO+n9NZ/Ro+Fy1p986OReRGxF2VEMUy0mi6poZ7Tam o2vCjmP8kS5+5IXN8St3JBt75bU2D7qllOFcx3NghGZAHYgs2ODCbx0Rfc3zUB+V8T WL0Cf+wKVzC4RNjQra74ObFzsIitOCrgRD418GHlx60yw+B9d9wFvocxMt6K0o9M29 0HsOIhGXwkIqA== 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 5.12 16/43] watchdog: sc520_wdt: Fix possible use-after-free in wdt_turnoff() Date: Sat, 10 Jul 2021 19:48:48 -0400 Message-Id: <20210710234915.3220342-16-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210710234915.3220342-1-sashal@kernel.org> References: <20210710234915.3220342-1-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-watchdog@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 e66e6b905964..ca65468f4b9c 100644 --- a/drivers/watchdog/sc520_wdt.c +++ b/drivers/watchdog/sc520_wdt.c @@ -186,7 +186,7 @@ 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