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 141F4C07E9B for ; Mon, 19 Jul 2021 15:00:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EEEA361002 for ; Mon, 19 Jul 2021 15:00:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242657AbhGSOUQ (ORCPT ); Mon, 19 Jul 2021 10:20:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:53904 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242363AbhGSOTI (ORCPT ); Mon, 19 Jul 2021 10:19:08 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0F8D0610D2; Mon, 19 Jul 2021 14:59:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626706787; bh=n8HH0ifXpBfgFOKff9LgCjq0R3YigGwqXA0aKClj30o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iIYsO0geHCLVMRkTGYaglTuof+8pBKNCMlXJB5pkS3LDvhxlwv27yQvXnATO3aFv6 G1L6albyDrkRbawyhBnX1ru1XinyXxlYUBBYDPqOMR/DtWC3j/giMorls9pmM7X/cc kpgqwqjFJPtHvxO8e/ImbsLe9ilyQm3u+nbgwyGs= 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 4.4 098/188] atm: nicstar: Fix possible use-after-free in nicstar_cleanup() Date: Mon, 19 Jul 2021 16:51:22 +0200 Message-Id: <20210719144935.964066937@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 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 49da83f87170..486d7a114031 100644 --- a/drivers/atm/nicstar.c +++ b/drivers/atm/nicstar.c @@ -298,7 +298,7 @@ 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