{"id":2224704,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2224704/?format=json","web_url":"http://patchwork.ozlabs.org/project/netfilter-devel/patch/ao4yv2o0cv8dPaKxuSYQGhLvUbSEyoqb0s32In5v6LNK1DLu9OWdQFFMZ_tuc1i-CcOLr1MXZYgpOBZcGQTBuI1swdQGygi24_RtIZ9sHbo=@protonmail.com/","project":{"id":26,"url":"http://patchwork.ozlabs.org/api/1.1/projects/26/?format=json","name":"Netfilter Development","link_name":"netfilter-devel","list_id":"netfilter-devel.vger.kernel.org","list_email":"netfilter-devel@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null},"msgid":"","date":"2026-04-17T19:41:32","name":"doc: note meta cgroup returns zero on cgroupv2-only hosts","commit_ref":null,"pull_url":null,"state":"accepted","archived":true,"hash":"4cc0d6bd136273672c7f2d94d3b84eeb890740c9","submitter":{"id":93180,"url":"http://patchwork.ozlabs.org/api/1.1/people/93180/?format=json","name":"Avinash H. Duduskar","email":"avinashhd@protonmail.com"},"delegate":{"id":11902,"url":"http://patchwork.ozlabs.org/api/1.1/users/11902/?format=json","username":"strlen","first_name":"Florian","last_name":"Westphal","email":"fw@strlen.de"},"mbox":"http://patchwork.ozlabs.org/project/netfilter-devel/patch/ao4yv2o0cv8dPaKxuSYQGhLvUbSEyoqb0s32In5v6LNK1DLu9OWdQFFMZ_tuc1i-CcOLr1MXZYgpOBZcGQTBuI1swdQGygi24_RtIZ9sHbo=@protonmail.com/mbox/","series":[{"id":500396,"url":"http://patchwork.ozlabs.org/api/1.1/series/500396/?format=json","web_url":"http://patchwork.ozlabs.org/project/netfilter-devel/list/?series=500396","date":"2026-04-17T19:41:32","name":"doc: note meta cgroup returns zero on cgroupv2-only hosts","version":1,"mbox":"http://patchwork.ozlabs.org/series/500396/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2224704/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2224704/checks/","tags":{},"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","netfilter-devel@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n secure) header.d=protonmail.com header.i=@protonmail.com header.a=rsa-sha256\n header.s=protonmail3 header.b=RyRKmu/F;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c0a:e001:db::12fc:5321; helo=sea.lore.kernel.org;\n envelope-from=netfilter-devel+bounces-12008-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=protonmail.com header.i=@protonmail.com\n header.b=\"RyRKmu/F\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=109.224.244.30","smtp.subspace.kernel.org;\n dmarc=pass (p=quarantine dis=none) header.from=protonmail.com","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=protonmail.com"],"Received":["from sea.lore.kernel.org (sea.lore.kernel.org\n [IPv6:2600:3c0a:e001:db::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fy4yT4k51z1yD3\n\tfor ; Sat, 18 Apr 2026 05:41:53 +1000 (AEST)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sea.lore.kernel.org (Postfix) with ESMTP id B558A30226BE\n\tfor ; Fri, 17 Apr 2026 19:41:48 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 9550031B810;\n\tFri, 17 Apr 2026 19:41:47 +0000 (UTC)","from mail-24430.protonmail.ch (mail-24430.protonmail.ch\n [109.224.244.30])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id E22CB27E056\n\tfor ; Fri, 17 Apr 2026 19:41:44 +0000 (UTC)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1776454907; cv=none;\n b=MfK/3OD0r3YGkvLQbQxsijTGWxMu3tqnf6KCaoOl5xuVmD4SupnX4BkUVPl/vXKJaTLhkdCid+Wh49xR2OeKxaQNx1XTamZlApL0/ls37poWk7eQFHibf+dNl2SyfWA1/d0/a6XDq/xC3cffY/b6XRFg3D7X2O4pyY7X7700svY=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1776454907; c=relaxed/simple;\n\tbh=qCPCvrhkOsGPGd3amlDjI5jADwpOQxEPgs5CVKAAYR8=;\n\th=Date:To:From:Cc:Subject:Message-ID:MIME-Version:Content-Type;\n b=Gd9nfuA0AFqh86WJSwxTdZz97wuN9J3//4AiR4/0zPTkVP6VrxAQvtZ/WMDkODSqIC30UMUEuliNCZwNM/pAkFAN86wPORRqoNl6HfwIZ5bSUGiu/BhvySwHYhHlE/CHnggjaOl0KR4rb+f9CYrJfPuBNRP1lkjU328OICjRUBs=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=pass (p=quarantine dis=none) header.from=protonmail.com;\n spf=pass smtp.mailfrom=protonmail.com;\n dkim=pass (2048-bit key) header.d=protonmail.com header.i=@protonmail.com\n header.b=RyRKmu/F; arc=none smtp.client-ip=109.224.244.30","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com;\n\ts=protonmail3; t=1776454896; x=1776714096;\n\tbh=qCPCvrhkOsGPGd3amlDjI5jADwpOQxEPgs5CVKAAYR8=;\n\th=Date:To:From:Cc:Subject:Message-ID:Feedback-ID:From:To:Cc:Date:\n\t Subject:Reply-To:Feedback-ID:Message-ID:BIMI-Selector;\n\tb=RyRKmu/FHHNf3GEVB2TKbX8Gns+/hXpYAeAH30UxAHVvnC5+gf7J9DrbF37MAEDFO\n\t WKYgf7YN06vA0Dow78z2fk4D+OXohuAR9pDJZyVo4vpBVQ4DxTUWEhiIDJYGJdeX6S\n\t MNN+fsI2D1jSD3iKRp7KD15T42jFWoTX7+nZu4iNv9LSC/R8YXst6k4rwhNUZh7S1f\n\t 0DJSyKlI62jYKmjDm5xKIlH1JKd8GfkANbHHjCOJdRFIJKUPaWx7pPhl7nwSIDrSxm\n\t v06brqe5bj/zSuK2sZmISop/brrtPpclUF/8zctZJrn+LyYMJ9Iz5Pj7pcDHTdvWPF\n\t j+vl4i2HSmvGw==","Date":"Fri, 17 Apr 2026 19:41:32 +0000","To":"\"netfilter-devel@vger.kernel.org\" ","From":"\"Avinash H. Duduskar\" ","Cc":"\"pablo@netfilter.org\" ,\n \"mkoutny@suse.com\" ","Subject":"[PATCH] doc: note meta cgroup returns zero on cgroupv2-only hosts","Message-ID":"\n ","Feedback-ID":"10914616:user:proton","X-Pm-Message-ID":"5d500efda6956afbf749d93dff5fe27c4fe85851","Precedence":"bulk","X-Mailing-List":"netfilter-devel@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Transfer-Encoding":"quoted-printable"},"content":"Commit 2ff29969 (\"doc: Clarify cgroup meta variable\") corrected the\nterminology and pointed readers to socket cgroupv2. The man page still\ngives no indication that meta cgroup silently returns zero on\ncgroupv2-only hosts with CONFIG_CGROUP_NET_CLASSID=y (the distribution\ndefault) and no active net_cls hierarchy, the common configuration\non modern systems. Rules load without error and match nothing.\n\nMake the behaviour explicit in the meta expression types table.\n\nScript to reproduce the issue: https://gist.github.com/Strykar/512e08f9fc2e7ccdcac971fd1719489a\n\nSigned-off-by: Avinash H. Duduskar \n---\n doc/primary-expression.txt | 3 ++-\n 1 file changed, 2 insertions(+), 1 deletion(-)","diff":"diff --git a/doc/primary-expression.txt b/doc/primary-expression.txt\nindex bd80cd7f..f09817fe 100644\n--- a/doc/primary-expression.txt\n+++ b/doc/primary-expression.txt\n@@ -117,7 +117,8 @@ devgroup\n outgoing device group|\n devgroup\n |cgroup|\n-control group net_cls.classid (for matching on cgroupv2, see *socket cgroupv2*)|\n+control group net_cls.classid; reads zero on cgroupv2-only hosts without an\n+active net_cls hierarchy (for matching on cgroupv2, see *socket cgroupv2*)|\n integer (32 bit)\n |random|\n pseudo-random number|\n","prefixes":[]}