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 39967C07E95 for ; Sun, 11 Jul 2021 00:00:23 +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 E1A7360234 for ; Sun, 11 Jul 2021 00:00:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E1A7360234 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=czqbtzXZPm4Eu6ooUyQ9qM01V64M7xZwCS2HJk+PT3k=; b=LQtzOaa2eni9L6 PC7NcwGXV+eLdcJHQDs/nm7e8ZSPr4BCuelk0f5Xr38mQs8j3VRmljNNqy9ePA0OsLHX0o0hgUaWh O2Jkj3lUlnyTG8ywq/C7juMWJS7ECQUyo4CTIJ7ax3qTVJNoIAe7DFxkM6/TH+hWUNWfI1ha/JvNC HZm4dbvmfDAHcf7OdlBpCXcO8IcjYxkJ7N1D9RHRRuFB+KizUd57gXauAnybXtPYilm/i6wojghLh 2wml6Hjbqoa9NKjzhJZp8BgTqvbyvRXCOtARliBkTZDZYl5j/yyYqxQJircH7ZODnlXhzYoAnhjaQ N5O71VYjcZgwuPdKYv3w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m2Mrh-004MWs-0b; Sat, 10 Jul 2021 23:58:34 +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 1m2MmB-004JVP-5k for linux-arm-kernel@lists.infradead.org; Sat, 10 Jul 2021 23:52:52 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id C3E6E61428; Sat, 10 Jul 2021 23:52:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625961170; bh=zsX6P8+wsgbmqJgIM2hsJSHm4Qlrw2k1kf5DeSgcSvU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GvZa2XTTMcz72H7HcLbwBE3bw43LcRmeqMQXojKWP05Ru7uJz04OEcxJ1lbdqOQ+z sVWtEX9ZaTVFn9hsNGvAS2FFnivZ7oP7Fe6kNEl0EW2aL8w0d1nDwx4FJP1JvQju5i Jr8iyeQzdlnB7hRhdMDj0VZ4bzPCe6VoJRKHkEk0L/iNiSybh2XAn5RQ9ALCBkhX/o 3HP8R8uDP3SbfPC9jmWkNQsE+nFu8tfgQuM1/LgRaxDgkVxoFFEXFrzTjiCD1wW9I2 GCS5CYjo07srAKWH+CcWHINfF80FQ52RW/sbblBV7LWU/6W+fc8qnyW1m+GfqUjRc8 p5Ifxpkdh+sRg== 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 4.9 07/16] watchdog: Fix possible use-after-free by calling del_timer_sync() Date: Sat, 10 Jul 2021 19:52:31 -0400 Message-Id: <20210710235240.3222618-7-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210710235240.3222618-1-sashal@kernel.org> References: <20210710235240.3222618-1-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_165251_353231_E314A53C 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 fd171e6caa16..1b63d1d85aa0 100644 --- a/drivers/watchdog/lpc18xx_wdt.c +++ b/drivers/watchdog/lpc18xx_wdt.c @@ -300,7 +300,7 @@ 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 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