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 6F5DCC07E9B for ; Sat, 10 Jul 2021 23:51:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 543C961362 for ; Sat, 10 Jul 2021 23:51:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233257AbhGJXyB (ORCPT ); Sat, 10 Jul 2021 19:54:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:41268 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232827AbhGJXxX (ORCPT ); Sat, 10 Jul 2021 19:53:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7059C613FE; Sat, 10 Jul 2021 23:50:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625961037; bh=xWCCHaF5NQH3bwlPXq7cZGPq7DcVswBFm6vzcPVvN44=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ausojwp/os5x0zEOFg3oxGMqivSkRggxBkFgP4KKxVeQvghVPqS8qcMgpGzLhUB8S Nvpn2jGtDVYLixU0j26iSt18/qG8Rjq7mdr5rh9Iwzqmem1Y36fT7wKCkLwwsAGAeJ cDTk3YVHhW5OYbUu3Wzkn39mHnQZpqdVbryXQeUfM7v7rsoGFezVgU5ziAjJfHElTJ zhe6J8N5YycAV4CVBPkuUDzsOtX1T2IzsGxB1vWeWoTyX5iARhAMOZLALA9X1ocaat kzaca6pGBz5e/OQ6MqvPUNJafYnlykfhVAB9yGffSk/cyqhY3iB9ndqOb9dFnfJk2M cn1Stc2N67wYg== 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 15/37] watchdog: sc520_wdt: Fix possible use-after-free in wdt_turnoff() Date: Sat, 10 Jul 2021 19:49:53 -0400 Message-Id: <20210710235016.3221124-15-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 90b7c141132244e8e49a34a4c1e445cce33e07f4 ] 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/1620716691-108460-1-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/sc520_wdt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/watchdog/sc520_wdt.c b/drivers/watchdog/sc520_wdt.c index e66e6b905964..ca65468f4b9c 100644 --- a/drivers/watchdog/sc520_wdt.c +++ b/drivers/watchdog/sc520_wdt.c @@ -186,7 +186,7 @@ static int wdt_startup(void) static int wdt_turnoff(void) { /* Stop the timer */ - del_timer(&timer); + del_timer_sync(&timer); /* Stop the watchdog */ wdt_config(0); -- 2.30.2