From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: mail.toke.dk; spf=pass smtp.mailfrom=; dkim=pass header.d=trailofbits.com; arc=pass; dmarc=pass (Used From Domain Record) header.from=trailofbits.com policy.dmarc=reject Received: from mail-lf1-x12d.google.com (mail-lf1-x12d.google.com [IPv6:2a00:1450:4864:20::12d]) by mail.toke.dk (Postfix) with ESMTPS id 4AD2812A1FE0 for ; Mon, 29 Jun 2026 19:25:10 +0200 (CEST) Received: by mail-lf1-x12d.google.com with SMTP id 2adb3069b0e04-5aeba1a36dfso949767e87.2 for ; Mon, 29 Jun 2026 10:25:10 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1782753908; cv=none; d=google.com; s=arc-20260327; b=jncrGgvNrstkRHtCZ4irMj9RUR7HNFo5ar4FdcUF3qPE8jJWDjQOH+6LMRIsuPY25a p0LDlXPbRmVWhDjVHkVKPL8mx+C4Y2H5DonTtYpHP+OOhYuwQQKtgz6V88ebsEZtD5KC glnVpU7D/EpR0XHNgr04nPAyAaK/AIqep+w+m/fR/PxCZ1sY51QvZA3/fBvOsSrOwJQt omiQSFBMSGMpBiUBY6kN286AnHtmYRi6B+KqnhI0wczFKt3oNBTKfYKq8V36USAFIBDC J0VZEDDiIwjpJzpd93NLQUYReiOy6qA70U140X2NSzIE9RaV/FK5NTLYmOK+Gn7tB1Ls gCrQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20260327; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:dkim-signature; bh=RNVxrOq7hCihwcX755hqKJJxRSsbZ+NdSq43Nnq6gMU=; fh=HehW/q989Nl6cv0eg/HEVLJeViLRj9p3b8k8X6Xv7uU=; b=W6Ohel1q+556kocRcjxt+7j33hA4wOqDTpWF34Ey0whDPsRv+Ai9zHtiRuVMR86biy pJyB66osnw5rFMPBWlGUGgizkLA2Mq3597+K66GMwuLe+Pd2Gs7M+JjBbUn7gS0LUwZA sAnnRuZi1ixNzFoifkJ/W4Iatfxx+rgvg72+GkgP//HaLkA7gtf7NGdbaklkXCBmAJo/ QHE1BuvZ1lNLM36DL8FVzXOneN2l8Ix2TP3TQbKGNkZPZMBh+of+PH5b1rgFCQ2LJ77N 51hRbIpdN154DIOKzGTPFEZox4FmYA4cMHWAub3ZCwDWKtAfjimvh8uUG1rSEBXK00bt gwIw==; darn=lists.bufferbloat.net ARC-Authentication-Results: i=1; mx.google.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=trailofbits.com; s=google; t=1782753908; x=1783358708; darn=lists.bufferbloat.net; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=RNVxrOq7hCihwcX755hqKJJxRSsbZ+NdSq43Nnq6gMU=; b=hDR53EwMDcBEVXgb2IexnjxZs5HEAbrTkQFoYhhF/+2TzdSWADSDOFlUa5Sew77qrp I9UCmNnIKD5t9gEviNc47u8ZxI1flHJjKHQPKTHeaHeHSHKJ4mwYBuPBHWeB2johGXkn YCZT0Nj4FlCITIpWqlBUFL3tHTXDLMvamKNFDW4nxbvJEzJ52IuVr/KTj5nEMNkkQV17 pqB5YK/fmclmtgmv0FdsioCbmtIttj4pG90L0Q4mBAuLfoyDQ6uiHeb3cc0EPTOIGm8b qJTA0SzDwJ5jWp9cAeAPxjHMHvsV6uiuHzsnPiU1eg7Ohu01Scqave4JOj/2WofikZys mljA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782753908; x=1783358708; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=RNVxrOq7hCihwcX755hqKJJxRSsbZ+NdSq43Nnq6gMU=; b=ovv0iJ3nhh0K7bXUtOxQmmEgeIFmfx5fSGMlJBgVzt6xQwTT2+Tw9MLAIzo4vpagOm fo5+osQ29kKHO1855NYKFtTLro459greZhYMEViHXFyMdm7f6yxACDRAdnvJ8HQVsoZk eRuZO0Dsh4PzRWEdHTfx5AF6QG1CFU1eF+fj9HhIkiBcF8K5H8m7eiRANXFfpmiZPK5N OinZOSzsN28YD95AY+vBipf/X6HXxDBCtx6ekTUeZccBsr0oQstxk1/SXL2GEfz/wSD5 Dc2ttKBjs+M+mrH6ZRX25xz5MjTfUZlriuHboSjgve9XcLix5F9BVHzMz34YeB+TkETY vrow== X-Forwarded-Encrypted: i=1; AHgh+RrI6e4LN2HzziYycj30G4DU+eLdvBurBtHqUenisDt3V+ILKUKrXqmOeVSw1v03leqhcSam@lists.bufferbloat.net X-Gm-Message-State: AOJu0YyA9hCPIxBN8rHkNpJOn2SfuRdrqlzevzk2L9rOpo7r/6U+cbrY flGeGBxBGOcLrcUf9KzHhMrCRVTPL9gKt7SHXSwcU1bfBptAj0sRoFt+cXkIJjtnP1DxYqELfTv pnK9MOQjsfPjyDwRKE3Mr/1Uaih/4rR3VrlievYYUng== X-Gm-Gg: AfdE7cknShPGcGSml5Bip18+hF835LRuWwwrtrA70+NoyWFqFw8LH7goy3RTgx8dbzj ksMUubXYb1EPqV88IEkz0huDRuhjZKrGiabsGym6ftDoW9xtbFV+37nSur++YYwduvnFR0RMLpv vCifjRwn/ya6jzsxKBBNNS3koN4fcr5P/jFYv+lAJtaCRTrUJZCpDlX37pVdCV8iAwJKpwiLJxy Ih3MbXYHYPuZEb5NRqHhwgFHiCsquKgxgq6GuHhU67Rbr8NKkE4ypaXdwhmNK19Q9+9ocY= X-Received: by 2002:a05:6512:a354:b0:5ae:9d0f:19f2 with SMTP id 2adb3069b0e04-5aebdb7d486mr43047e87.3.1782753907646; Mon, 29 Jun 2026 10:25:07 -0700 (PDT) MIME-Version: 1.0 References: <20260609232935.1602659.8545fdb04fbe.cake-overhead-underflow@trailofbits.com> <20260613142626.1b2183eb@kernel.org> In-Reply-To: <20260613142626.1b2183eb@kernel.org> From: Samuel Moelius Date: Mon, 29 Jun 2026 13:24:56 -0400 X-Gm-Features: AVVi8CehuZasSGDM7tdu5ZNnK7k4rkh3SCVj8V71oPROccnLp1Vsy7jEK2VpmsU Message-ID: To: Jakub Kicinski Cc: =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= , Jamal Hadi Salim , Jiri Pirko , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , "moderated list:CAKE QDISC" , "open list:TC subsystem" , open list Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-MailFrom: sam.moelius@trailofbits.com X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation Message-ID-Hash: LEY4X6NECD3A7YQAFTYWRE5VIP6Z6PRO X-Message-ID-Hash: LEY4X6NECD3A7YQAFTYWRE5VIP6Z6PRO X-Mailman-Approved-At: Tue, 30 Jun 2026 11:43:19 +0200 X-Mailman-Version: 3.3.10 Precedence: list Subject: [Cake] Re: [PATCH net v2] net/sched: cake: reject overhead values that underflow length List-Id: Cake - FQ_codel the next generation Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On Sat, Jun 13, 2026 at 5:26=E2=80=AFPM Jakub Kicinski wr= ote: > > On Tue, 9 Jun 2026 23:29:36 +0000 Samuel Moelius wrote: > > +static const struct netlink_range_validation_signed cake_overhead_rang= e =3D { > > + .min =3D -64, > > + .max =3D 256, > > Both Sashiko's complain - these values are neither safe nor sufficient. > > How was the -64 chosen? It looks suspiciously close the min ethernet > frame length. That's how it was chosen. But as you've shown, it was not a good choice. I would like to submit a revised patch that does the check on the datapath, as you suggested. Should I send that patch? Or would you prefer to wait for a response from Toke?