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=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 2F8ABC11F66 for ; Sat, 10 Jul 2021 23:49:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DB2961356 for ; Sat, 10 Jul 2021 23:49:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232532AbhGJXwi (ORCPT ); Sat, 10 Jul 2021 19:52:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:39214 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232336AbhGJXwZ (ORCPT ); Sat, 10 Jul 2021 19:52:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 97D0160234; Sat, 10 Jul 2021 23:49:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625960979; bh=0rOQmzH2/RHjeIWMPO1I5FaTDOuQ4tbgwtr7wXAqSH0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=i7sCRq5nSSgGpqhDOgHF1daHfDuuQfKA4hqLmCKffvyN2UKTJDvW1U8oDVSXufw6g PZkNWfPlahSpDNAETtzaLIkrJk+eInNXGfFydnVc8u4lwTWqS9sxyFv36Bcju9hAgI +IpX4WDSxLUkxRRBMTl29ieQybxlqUaLtH8y+gz+WWSI5XoMQXUqrYhXXxDkUP9Lbk SNmLn2EMT1qfMI2zbylb+fJmcesqieoiaxRowTWAZgkgEyJfFC5IFW2afTFySEyqeI Yuyj9CPsUVk4bjihXk+Ez1Bo6AVkiy42gE0l7F74b6XPr5gLlTMhJpIsW4MHWLtYO+ fEUkp255gWz8A== 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 15/43] watchdog: Fix possible use-after-free in wdt_startup() Date: Sat, 10 Jul 2021 19:48:47 -0400 Message-Id: <20210710234915.3220342-15-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 c08a6b31e4917034f0ed0cb457c3bb209576f542 ] 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/1620716495-108352-1-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/sbc60xxwdt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/watchdog/sbc60xxwdt.c b/drivers/watchdog/sbc60xxwdt.c index a947a63fb44a..7b974802dfc7 100644 --- a/drivers/watchdog/sbc60xxwdt.c +++ b/drivers/watchdog/sbc60xxwdt.c @@ -146,7 +146,7 @@ static void wdt_startup(void) static void wdt_turnoff(void) { /* Stop the timer */ - del_timer(&timer); + del_timer_sync(&timer); inb_p(wdt_stop); pr_info("Watchdog timer is now disabled...\n"); } -- 2.30.2