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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 C1F24C43219 for ; Sat, 4 May 2019 04:59:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 91176206DF for ; Sat, 4 May 2019 04:59:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726277AbfEDE7F (ORCPT ); Sat, 4 May 2019 00:59:05 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:56428 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725801AbfEDE7F (ORCPT ); Sat, 4 May 2019 00:59:05 -0400 Received: from localhost (unknown [75.104.87.19]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 1255314D99A6F; Fri, 3 May 2019 21:58:57 -0700 (PDT) Date: Sat, 04 May 2019 00:58:53 -0400 (EDT) Message-Id: <20190504.005853.22857057952226160.davem@davemloft.net> To: mcroce@redhat.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, jhs@mojatatu.com, xiyou.wangcong@gmail.com, jiri@resnulli.us, vladbu@mellanox.com Subject: Re: [PATCH net] cls_matchall: avoid panic when receiving a packet before filter set From: David Miller In-Reply-To: <20190502085105.2967-1-mcroce@redhat.com> References: <20190502085105.2967-1-mcroce@redhat.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Fri, 03 May 2019 21:59:04 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Matteo Croce Date: Thu, 2 May 2019 10:51:05 +0200 > When a matchall classifier is added, there is a small time interval in > which tp->root is NULL. If we receive a packet in this small time slice > a NULL pointer dereference will happen, leading to a kernel panic: ... > Fix this by adding a NULL check in mall_classify(). > > Fixes: ed76f5edccc9 ("net: sched: protect filter_chain list with filter_chain_lock mutex") > Signed-off-by: Matteo Croce Applied and queued up for -stable, thanks.