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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 DE044C07E9D for ; Mon, 19 Jul 2021 15:23:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C1FD66113E for ; Mon, 19 Jul 2021 15:23:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343716AbhGSOmu (ORCPT ); Mon, 19 Jul 2021 10:42:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:60798 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244082AbhGSOk0 (ORCPT ); Mon, 19 Jul 2021 10:40:26 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CA9C261002; Mon, 19 Jul 2021 15:21:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626708064; bh=9iYzRJWA9VUMjadf/f1wc5risnPUGVQ9g4tnOeVEqoY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gccV+7R6g35CiOh21sZDdE3Lh8iwo02Ix6llnHNNmCkXeOzfz7Rm/LKy4rrJ7MTNf 2yJurucfd3fyGcWTmX31Y5vSdfDx8VIfSSQn7ft1NXGBNBPVVBzh7g+uhGloiL9rre yAfp629yqZUBsIzT9CpCsm7t88dLPFMNti7W0/Lo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hulk Robot , Zou Wei , "David S. Miller" , Sasha Levin Subject: [PATCH 4.14 166/315] mISDN: fix possible use-after-free in HFC_cleanup() Date: Mon, 19 Jul 2021 16:50:55 +0200 Message-Id: <20210719144948.352823559@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144942.861561397@linuxfoundation.org> References: <20210719144942.861561397@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zou Wei [ Upstream commit 009fc857c5f6fda81f2f7dd851b2d54193a8e733 ] 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 Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/isdn/hardware/mISDN/hfcpci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/isdn/hardware/mISDN/hfcpci.c b/drivers/isdn/hardware/mISDN/hfcpci.c index d2e401a8090e..3e73cb5b8304 100644 --- a/drivers/isdn/hardware/mISDN/hfcpci.c +++ b/drivers/isdn/hardware/mISDN/hfcpci.c @@ -2349,7 +2349,7 @@ static void __exit HFC_cleanup(void) { if (timer_pending(&hfc_tl)) - del_timer(&hfc_tl); + del_timer_sync(&hfc_tl); pci_unregister_driver(&hfc_driver); } -- 2.30.2