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 242E5C636C9 for ; Mon, 19 Jul 2021 16:24:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0FFEE6128A for ; Mon, 19 Jul 2021 16:24:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348480AbhGSPn7 (ORCPT ); Mon, 19 Jul 2021 11:43:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:53798 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343861AbhGSO7X (ORCPT ); Mon, 19 Jul 2021 10:59:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 727F66128D; Mon, 19 Jul 2021 15:37:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626709053; bh=QxMsqh2Dtak9GW1fH42izSg9EdwGEWoPHdlqZYEFBgo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eifdSgjoNcRcVgLnMjlU3noDpeLtAMPawVbcseRuy0jqXsiuOixO8gq1aXRxKXyVG zokkcxiSnjSNJGw0fhRUXxMUhxFychbgXiO0jJ5Z7kIK1kI3+jOLMGMiguLCLqgXOJ fsijpwwg5B5KOzV5GLHtqBnHVzZCkste1dWDsj7A= 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 4.19 235/421] atm: nicstar: Fix possible use-after-free in nicstar_cleanup() Date: Mon, 19 Jul 2021 16:50:46 +0200 Message-Id: <20210719144954.566056631@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144946.310399455@linuxfoundation.org> References: <20210719144946.310399455@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 34e7434ba4e97f4b85c1423a59b2922ba7dff2ea ] 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/atm/nicstar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/atm/nicstar.c b/drivers/atm/nicstar.c index 0d3754a4ac20..5281db3d6783 100644 --- a/drivers/atm/nicstar.c +++ b/drivers/atm/nicstar.c @@ -296,7 +296,7 @@ static void __exit nicstar_cleanup(void) { XPRINTK("nicstar: nicstar_cleanup() called.\n"); - del_timer(&ns_timer); + del_timer_sync(&ns_timer); pci_unregister_driver(&nicstar_driver); -- 2.30.2