From patchwork Thu Jul 15 18:36:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 478165 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=-19.4 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 C392DC636CB for ; Thu, 15 Jul 2021 18:55:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE38C6100A for ; Thu, 15 Jul 2021 18:55:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241400AbhGOS6K (ORCPT ); Thu, 15 Jul 2021 14:58:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:34342 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241614AbhGOS5S (ORCPT ); Thu, 15 Jul 2021 14:57:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0B780613CC; Thu, 15 Jul 2021 18:54:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626375263; bh=9upz0cKdc/qYU4JjyOzTGWrs6l3cCYP97s9qfpHPtkc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=T3heFHEVwmRZpMSfPH63rklzbihZ5Nviq3TDb9WINEhexh7UDtgE4/hZGx+bzLaVh xRxj4Esnvtfe61DnvDj21GFWD68X874Y4yLhV6pXIG0GD5zcyMFLNSfj2sZi7jck8Y vOeRFpkMEcDLhEzQlJcdlmE5xkgphK1c7H2UochQ= 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 5.12 014/242] mISDN: fix possible use-after-free in HFC_cleanup() Date: Thu, 15 Jul 2021 20:36:16 +0200 Message-Id: <20210715182554.266053843@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210715182551.731989182@linuxfoundation.org> References: <20210715182551.731989182@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 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 56bd2e9db6ed..e501cb03f211 100644 --- a/drivers/isdn/hardware/mISDN/hfcpci.c +++ b/drivers/isdn/hardware/mISDN/hfcpci.c @@ -2342,7 +2342,7 @@ 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); }