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=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 E0A78C12002 for ; Mon, 19 Jul 2021 15:02:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA9B76120A for ; Mon, 19 Jul 2021 15:02:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241879AbhGSOVX (ORCPT ); Mon, 19 Jul 2021 10:21:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:54960 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242340AbhGSOTF (ORCPT ); Mon, 19 Jul 2021 10:19:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B777661073; Mon, 19 Jul 2021 14:59:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626706785; bh=zGOVYjwyMffJLWfigNL2olJxhT7aPhNmZaFHOVgs7cA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hmNgUw5Z/FKZ9ln8Nh7bP5ImVrsU6ToGlqQMDpkjW8fNzQdaO/HLpab4fp3h8cRog ZekqYRMbp7GNi9V/F1L56hRhEQ1eq8qHuCW8kq/QNYRxS3grL//OTo+/n7V8QnBrKE oJ/AQ7PeHqoKK3tmZBqiSXs1jNBaGkFUUJFgMgtk= 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 4.4 097/188] mISDN: fix possible use-after-free in HFC_cleanup() Date: Mon, 19 Jul 2021 16:51:21 +0200 Message-Id: <20210719144935.739756396@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144913.076563739@linuxfoundation.org> References: <20210719144913.076563739@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: linux-kernel@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 ff48da61c94c..89cf1d695a01 100644 --- a/drivers/isdn/hardware/mISDN/hfcpci.c +++ b/drivers/isdn/hardware/mISDN/hfcpci.c @@ -2352,7 +2352,7 @@ 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