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=-4.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 B93C5C433B4 for ; Tue, 20 Apr 2021 04:27:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 92999613AB for ; Tue, 20 Apr 2021 04:27:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229616AbhDTE1u (ORCPT ); Tue, 20 Apr 2021 00:27:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229516AbhDTE1t (ORCPT ); Tue, 20 Apr 2021 00:27:49 -0400 Received: from mail-ot1-x335.google.com (mail-ot1-x335.google.com [IPv6:2607:f8b0:4864:20::335]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78748C061763 for ; Mon, 19 Apr 2021 21:27:17 -0700 (PDT) Received: by mail-ot1-x335.google.com with SMTP id c8-20020a9d78480000b0290289e9d1b7bcso20640929otm.4 for ; Mon, 19 Apr 2021 21:27:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=a6ri1YBEsbxl4sCS/8ACK27mxPbtgmS0w+6VGuB6PD4=; b=F737NdZhHiHZWR+h5TCxK/UBSVO1FgSc4EVLzNlW98bMTw7y0T53ZTCZZRL6yO48qT MBkK14hRUP1dxQ3MYNQT+XAWjkk+c64YYuAMSqDBiAm4vTBuBGmQvi3SqNgUtmNrkC2A VIeMthluKhIDoT7tqbnihgqcxHeUa8GQMY7l+xgeb4ff229nP2GeMxeJzUVyRI2QTyjG XppAyoPr638vD/VdzCKqyDG79Y+Vl28LPH7H1c+1VjNZzDdBKReMYQcYcqnyRI7kxyIQ YQrvDlpyt/3mE6H2NaYFUSbnDYA0Z5atrpOtIydLnVgQVKZOmSYmLiVYk3pxZ6xENOoa +Yaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=a6ri1YBEsbxl4sCS/8ACK27mxPbtgmS0w+6VGuB6PD4=; b=pu4qhRZUQy4RjEAX+okvf6p/+yMBfrpCGk4h4DYrQLBcHSEtAfkCAM0MDRY4hLSzSy zirzyKdEwAZgoiN4xsRlcd6kSod+xoYTygP3C+ZLFoUjANUtI62Ur3jRjpFdHbaV93Xn hF2dKhehaHQleEEFkXDa69UOA6xcKD4k57mci65KkypKTJIPYRHlIEugRkL3NZHYBVeh M3lDSHbHUHkbnsYp1BcuVp+csCavh7zyiNKTMo9dpHZsuo9aBwsZOAHIo5KFgC1XOXrc poOyswyFxkJnM78kaWv7v9V9hmoSryQkrT+oNEvNhWXCkJp18RuhZi4ujHbTViLqVwmn Fj3w== X-Gm-Message-State: AOAM532sdNiktEjiSj3DUw280EGpo0+0NRekubwIez5oMDgJtKEe/V4n 1Y8awTWxA3YSnYJhKUP3B6m/maKwYOg= X-Google-Smtp-Source: ABdhPJzQePJ9GUntN+GABu4o2yGyk1KSmIEOQ0QK9yV5WdOVz0PbUX3Hx4Vbeb5zN7vsWSgmwaUK7A== X-Received: by 2002:a9d:3a3:: with SMTP id f32mr9577381otf.205.1618892836930; Mon, 19 Apr 2021 21:27:16 -0700 (PDT) Received: from Davids-MacBook-Pro.local ([8.45.42.15]) by smtp.googlemail.com with ESMTPSA id c65sm3648083oia.47.2021.04.19.21.27.15 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 19 Apr 2021 21:27:16 -0700 (PDT) Subject: Re: [PATCH 2/2] neighbour: allow NUD_NOARP entries to be forced GCed To: Kasper Dupont Cc: netdev@vger.kernel.org, Thadeu Lima de Souza Cascardo , davem@davemloft.net, kuba@kernel.org, dsahern@kernel.org, Kasper Dupont References: <20210317185320.1561608-1-cascardo@canonical.com> <20210317185320.1561608-2-cascardo@canonical.com> <20210419164429.GA2295190@sniper.kasperd.net> <0b502406-1a86-faec-ff46-c530145b90cf@gmail.com> <20210419175205.GA2375672@sniper.kasperd.net> From: David Ahern Message-ID: <71ea409d-7065-821a-f958-1736d015e4ff@gmail.com> Date: Mon, 19 Apr 2021 21:27:13 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.9.1 MIME-Version: 1.0 In-Reply-To: <20210419175205.GA2375672@sniper.kasperd.net> Content-Type: text/plain; charset=UTF-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 4/19/21 10:52 AM, Kasper Dupont wrote: > On 19/04/21 10.10, David Ahern wrote: >> On 4/19/21 9:44 AM, Kasper Dupont wrote: >>> >>> Is there any update regarding this change? >>> >>> I noticed this regression when it was used in a DoS attack on one of >>> my servers which I had upgraded from Ubuntu 18.04 to 20.04. >>> >>> I have verified that Ubuntu 18.04 is not subject to this attack and >>> Ubuntu 20.04 is vulnerable. I have also verified that the one-line >>> change which Cascardo has provided fixes the vulnerability on Ubuntu >>> 20.04. >>> >> >> your testing included both patches or just this one? > > I applied only this one line change on top of the kernel in Ubuntu > 20.04. The behavior I observed was that without the patch the kernel > was vulnerable and with that patch I was unable to reproduce the > problem. This patch should be re-submitted standalone for -net > > The other longer patch is for a different issue which Cascardo > discovered while working on the one I had reported. I don't have an > environment set up where I can reproduce the issue addressed by that > larger patch. > The first patch is the one I have concerns about.