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=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 B9883C4321A for ; Fri, 28 Jun 2019 21:37:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 94F892086D for ; Fri, 28 Jun 2019 21:37:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726586AbfF1VhB (ORCPT ); Fri, 28 Jun 2019 17:37:01 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:52230 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725783AbfF1VhB (ORCPT ); Fri, 28 Jun 2019 17:37:01 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::d71]) (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 EE26C13CB3060; Fri, 28 Jun 2019 14:37:00 -0700 (PDT) Date: Fri, 28 Jun 2019 14:37:00 -0700 (PDT) Message-Id: <20190628.143700.1074650648292410737.davem@davemloft.net> To: john.hurley@netronome.com Cc: netdev@vger.kernel.org, fw@strlen.de, jhs@mojatatu.com, simon.horman@netronome.com, jakub.kicinski@netronome.com, oss-drivers@netronome.com Subject: Re: [PATCH net-next 0/2] Track recursive calls in TC act_mirred From: David Miller In-Reply-To: <1561414416-29732-1-git-send-email-john.hurley@netronome.com> References: <1561414416-29732-1-git-send-email-john.hurley@netronome.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, 28 Jun 2019 14:37:01 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: John Hurley Date: Mon, 24 Jun 2019 23:13:34 +0100 > These patches aim to prevent act_mirred causing stack overflow events from > recursively calling packet xmit or receive functions. Such events can > occur with poor TC configuration that causes packets to travel in loops > within the system. > > Florian Westphal advises that a recursion crash and packets looping are > separate issues and should be treated as such. David Miller futher points > out that pcpu counters cannot track the precise skb context required to > detect loops. Hence these patches are not aimed at detecting packet loops, > rather, preventing stack flows arising from such loops. Series applied, thanks.