From owner-freebsd-security@freebsd.org Tue Apr 21 22:15:44 2020 Return-Path: Delivered-To: freebsd-security@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id CDB202BC859 for ; Tue, 21 Apr 2020 22:15:44 +0000 (UTC) (envelope-from carpeddiem@gmail.com) Received: from mail-il1-f177.google.com (mail-il1-f177.google.com [209.85.166.177]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 496HvM2whPz4JSt; Tue, 21 Apr 2020 22:15:43 +0000 (UTC) (envelope-from carpeddiem@gmail.com) Received: by mail-il1-f177.google.com with SMTP id s10so14194028iln.11; Tue, 21 Apr 2020 15:15:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=03oNog6XlhRcwYfJMPSbjY+IOgVjToTo2SQdB3JEuJE=; b=CN8zA1FRmJ6Od20RrveUJLQLTNPitDmz11JnFts8biBBtWpS5sreoXnnLzgBVDxiSg kHiLMJB37vbHTeIve4wc78GIxkgdt7YReoIqN+h1EsqwBmIDmDi73Mvj1D9Q1+L5N6XR bSJ3IuqNFd4fBnCrpL5+rTfLoahNmPRrqFNNP3KQmTC/Pfvqfyg5bUywzWJWRRkltvWa 2CXcBK3iumxW/KMNZp6ABjKtCY6cZ1K6IUBu3dTeIClgXrveJEvsDB5YHWNfP9xbYRNg Vo01CqBAQNCCvxWjWy0OaAlPJfCSIl0kBfXZNSxOSIMO3gvRKyZ5Jmfkg8HBlD9qVTY4 U3zQ== X-Gm-Message-State: AGi0PuYBzrTbDSwAqkKbpHKMeRo43ODqDp77j28r4Srob4/xpFBeWmEW iinsqhW01Vk+vSNoiDizY5XhLdpmodD6o5J/rFhsVAtu X-Google-Smtp-Source: APiQypIuixYjDIEpmVLXHV7oyb7FCidet3seJfg5LzFHxCrUokLdhlh7MKCX/7/Utxpw/RrX7Y4JSiy9ijc5kzSXuE4= X-Received: by 2002:a92:2910:: with SMTP id l16mr21116500ilg.256.1587507342281; Tue, 21 Apr 2020 15:15:42 -0700 (PDT) MIME-Version: 1.0 References: <20200421165514.C676C1CB78@freefall.freebsd.org> <54bfc0f6-be4c-349d-df87-8ba507803a04@grosbein.net> In-Reply-To: <54bfc0f6-be4c-349d-df87-8ba507803a04@grosbein.net> From: Ed Maste Date: Tue, 21 Apr 2020 18:15:29 -0400 Message-ID: Subject: Re: [FreeBSD-Announce] FreeBSD Security Advisory FreeBSD-SA-20:10.ipfw To: Eugene Grosbein , "Andrey V. Elsukov" Cc: freebsd-security@freebsd.org Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 496HvM2whPz4JSt X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of carpeddiem@gmail.com designates 209.85.166.177 as permitted sender) smtp.mailfrom=carpeddiem@gmail.com X-Spamd-Result: default: False [-3.55 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; RCVD_TLS_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; R_SPF_ALLOW(-0.20)[+ip4:209.85.128.0/17]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[freebsd.org]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[177.166.85.209.list.dnswl.org : 127.0.5.0]; IP_SCORE(-1.55)[ip: (-6.87), ipnet: 209.85.128.0/17(-0.40), asn: 15169(-0.43), country: US(-0.05)]; FORGED_SENDER(0.30)[emaste@freebsd.org,carpeddiem@gmail.com]; RWL_MAILSPIKE_POSSIBLE(0.00)[177.166.85.209.rep.mailspike.net : 127.0.0.17]; MIME_TRACE(0.00)[0:+]; R_DKIM_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:209.85.128.0/17, country:US]; FROM_NEQ_ENVFROM(0.00)[emaste@freebsd.org,carpeddiem@gmail.com]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Security issues \[members-only posting\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 21 Apr 2020 22:15:44 -0000 On Tue, 21 Apr 2020 at 15:29, Eugene Grosbein wrote: > > 21.04.2020 23:55, FreeBSD Security Advisories wrote: > > ============================================================================= > > FreeBSD-SA-20:10.ipfw Security Advisory > > The FreeBSD Project > > > > Topic: ipfw invalid mbuf handling > > [skip] > > > IV. Workaround > > > > No workaround is available. Systems not using the ipfw firewall are > > not vulnerable. > > This is not true. The problem affects only seldom used rules matching TCP packets > by list of TCP options (rules with "tcpoptions" keyword) and/or by TCP MSS size > (rules with matching "tcpmss" keyword, don't mix with "tcp-setmss" action keyword). I believe this is correct; what about this statement: No workaround is available. Systems not using the ipfw firewall, and systems that use the ipfw firewall but without any rules using "tcpoptions" or "tcpmss" keywords, are not affected.