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 979CAC11F6D for ; Sat, 10 Jul 2021 23:51:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7A2AF613BE for ; Sat, 10 Jul 2021 23:51:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233223AbhGJXx4 (ORCPT ); Sat, 10 Jul 2021 19:53:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:41208 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233240AbhGJXxV (ORCPT ); Sat, 10 Jul 2021 19:53:21 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 167F961369; Sat, 10 Jul 2021 23:50:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625961035; bh=0rOQmzH2/RHjeIWMPO1I5FaTDOuQ4tbgwtr7wXAqSH0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NuCKLBe1Ozwd+6KZuk/r9zK2n7b3JrBt1aHaT4F+G2Vq4PBIMLi86lDevOCdMHIyr QzTv6H882d7oCIfN3KAcrxsyrJR/cazvkoX+yNQ4bKgO/eEhiwOkfPnYyXOD9jICXr LUiy6nmqc0VQ3RRcsdMu+3xa7bAMQLN3lzL9I/vsLV3nHPibUxyVwkjImdyXhL0709 eGkgGAIeuZ2AEipLX0U1ph+ODZ7vUGmXiiamEePBGnoPoSjQYp0RQwh6BH8MTeTRvU 4SH5eDaSR0+gOk/xuD2eTZMydqQyVdCQD0yVQUBqB2DYpMHi5vIUVcIup1Ee30pbal 2HcYduFUq5qXQ== 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 5.10 14/37] watchdog: Fix possible use-after-free in wdt_startup() Date: Sat, 10 Jul 2021 19:49:52 -0400 Message-Id: <20210710235016.3221124-14-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210710235016.3221124-1-sashal@kernel.org> References: <20210710235016.3221124-1-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