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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 73FCEC07E95 for ; Sat, 10 Jul 2021 23:56:47 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 483FB61184 for ; Sat, 10 Jul 2021 23:56:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 483FB61184 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=5ZsvG9D2Iv9d9Fix6jCSwf0/jI9GnBBWXlujxqit9Xg=; b=fisQYdCoAbgehb qdcafYBfDjNEJRBR3ciwWJiWAL5J8REpVTbQWMcYxyneW7g+6oaLeZQVSH3TUyePf/XefObom5bhX pFpvNg+7/3d1f+wDjVlVobV1RMbc6ctVUjqMH7FPxdAow6OdSH5W6TJyhCmRNEdK6hccvLet6W1CR Hba5rxfD0vIwF1KwnWHXomGrDb56a0FnGnEzExk1shgjup42eGVNQpejgqBcqVEGEUjovlnQXffg+ 36o2Iazyv8BaIUj89ATh8Q1HbPIO9H9rZOQvkIvBpWPKw7UcsOtfTSV4v0Dwj7wBZUmo5vY1lKTbK PdEOzgpJMsJbhamXjpvg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m2MoM-004KpT-4e; Sat, 10 Jul 2021 23:55:07 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m2MlH-004Ipx-2i for linux-arm-kernel@lists.infradead.org; Sat, 10 Jul 2021 23:51:56 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id C17E8613EC; Sat, 10 Jul 2021 23:51:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625961114; bh=dhmSC8djzlNEEH0rfKbC8YM0a3TvsZctAFvqICu5E6o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c2OMKe7sKM27lrQa6oPmGO+g4buNggrY1kjNv5BneNZ0KfztlLB+CF/q53ZD9bVuS iZobHp/cGemLChsc2YWGeeHuw28zsO6CiPt1seCNhy0hsqC3UOoQtHCMLqnhohP0Zu +LQvnlHQvKLfsm0LGbuBMhNapSnmP9xFW5pwI9JArC7MORmiafrkxeZXsEK9shPe8a peOs5lqSMZDHMNUjrGaNvsdrULje7CpGtJ7PZV2DAiwTswQKmhCmEaf4+ZOzTIGiw6 TE14GGGIsPgCY/TyFF6UEhlUzuGghoIuxIDUnD/k1iDE3jHl2D9Mo/ilucgkMEfzIJ PBhdb2Ecctxsg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zou Wei , Hulk Robot , Guenter Roeck , Vladimir Zapolskiy , Wim Van Sebroeck , Sasha Levin , linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 4.19 08/22] watchdog: Fix possible use-after-free by calling del_timer_sync() Date: Sat, 10 Jul 2021 19:51:29 -0400 Message-Id: <20210710235143.3222129-8-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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210710_165155_207430_ED6489BF X-CRM114-Status: GOOD ( 12.98 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Zou Wei [ Upstream commit d0212f095ab56672f6f36aabc605bda205e1e0bf ] This driver'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 Acked-by: Vladimir Zapolskiy Link: https://lore.kernel.org/r/1620802676-19701-1-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/lpc18xx_wdt.c | 2 +- drivers/watchdog/w83877f_wdt.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/watchdog/lpc18xx_wdt.c b/drivers/watchdog/lpc18xx_wdt.c index 331cadb459ac..48580b6406c2 100644 --- a/drivers/watchdog/lpc18xx_wdt.c +++ b/drivers/watchdog/lpc18xx_wdt.c @@ -301,7 +301,7 @@ static int lpc18xx_wdt_remove(struct platform_device *pdev) struct lpc18xx_wdt_dev *lpc18xx_wdt = platform_get_drvdata(pdev); dev_warn(&pdev->dev, "I quit now, hardware will probably reboot!\n"); - del_timer(&lpc18xx_wdt->timer); + del_timer_sync(&lpc18xx_wdt->timer); watchdog_unregister_device(&lpc18xx_wdt->wdt_dev); clk_disable_unprepare(lpc18xx_wdt->wdt_clk); diff --git a/drivers/watchdog/w83877f_wdt.c b/drivers/watchdog/w83877f_wdt.c index 05658ecc0aa4..ec4641fc2d21 100644 --- a/drivers/watchdog/w83877f_wdt.c +++ b/drivers/watchdog/w83877f_wdt.c @@ -170,7 +170,7 @@ static void wdt_startup(void) static void wdt_turnoff(void) { /* Stop the timer */ - del_timer(&timer); + del_timer_sync(&timer); wdt_change(WDT_DISABLE); -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel