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 12874C07E9C for ; Sun, 11 Jul 2021 00:02:09 +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 DB7726113D for ; Sun, 11 Jul 2021 00:02:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DB7726113D 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=OrUbWvRuESQaTZrDfmpvwlMhSylPjyRJbG/LVCgdu/A=; b=UEbQ5VB6UZU3l0 dfQ1PHqaNlKWfLUsu7PISOQtGt6FJX2cIxF7vAs7hfn/jUcTm8vYk78Hl2Mh+OkYS7XtS53bgv+lF e4LVR5LMtHn1EpmU721y4RT+a6Z+lPcMSf3hCf7E+4xfSRQq35ytVEIBRFawFgGKIFztAZ+VaX/9c RwfsM5DvcxVG9fDTDEgkdxk0JXPVyNBwX6ystVHdVmx4GzE9TDqXsXv/aiOwQWp7mi4yTtvKsp22s 57LkOaWby3wAWsCeuD0GukCMT4emWxPLliFrpOB8HFltGMTfhKqa5EOcGkIqAW1OuznSkMCmQIJeX T3ano/r+B1pqqWm/FTLA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m2Mtk-004NUy-P4; Sun, 11 Jul 2021 00:00:41 +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 1m2MmX-004JkE-GC for linux-arm-kernel@lists.infradead.org; Sat, 10 Jul 2021 23:53:16 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id B5D9E613E5; Sat, 10 Jul 2021 23:53:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625961192; bh=hkADfCiMoQJ+risbIzZYtyX+fRNEebwVd2J4+7NsjoQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K+473WzxsJVlMlI//5oz5nzQQNOxdhQGKBoJNNY//jdtvWq4DTNwPt0D28QWlg1Tj /JYyCnVVdB3W5huPFWyomPPOC8L940caP6iSYMq937iEaXfAkumnUfAED0PoiHF/kE 8u+KgFBUUUvJH/E4BXU9Myzl3r56TNmBEne4Qpsk3SR41GhJopQZ1skiJDZ8BragOA dkkGqN20bQCLxd1g9fNKGrM6TE2d2rawFBknjUJPI8BiZ1LcI8bFu6nJV/y12nlb38 umQ7pS6ngTCeo/5jc9QXsKdcjhBs2RrI/LJI3sr/HrXPfxGqx8s36z+bwqzI7nn0hm 0+kO4yYtJkaXQ== 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 4.4 07/12] watchdog: Fix possible use-after-free by calling del_timer_sync() Date: Sat, 10 Jul 2021 19:52:57 -0400 Message-Id: <20210710235302.3222809-7-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210710235302.3222809-1-sashal@kernel.org> References: <20210710235302.3222809-1-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_165313_627848_5A1A099D X-CRM114-Status: GOOD ( 12.87 ) 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 ab7b8b185d99..fbdc0f32e666 100644 --- a/drivers/watchdog/lpc18xx_wdt.c +++ b/drivers/watchdog/lpc18xx_wdt.c @@ -309,7 +309,7 @@ static int lpc18xx_wdt_remove(struct platform_device *pdev) unregister_restart_handler(&lpc18xx_wdt->restart_handler); 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 f0483c75ed32..4b52cf321747 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