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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 70CEDC04A6B for ; Wed, 8 May 2019 14:58:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 37EBF20989 for ; Wed, 8 May 2019 14:58:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="rDQOPtuM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726956AbfEHO6b (ORCPT ); Wed, 8 May 2019 10:58:31 -0400 Received: from mail-pf1-f195.google.com ([209.85.210.195]:35555 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726614AbfEHO6a (ORCPT ); Wed, 8 May 2019 10:58:30 -0400 Received: by mail-pf1-f195.google.com with SMTP id t87so10060203pfa.2; Wed, 08 May 2019 07:58:30 -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=yEQ3QDmG4J4aCqR8TE4zPyewDF8Wu8jUX8cEw4gcVRM=; b=rDQOPtuMVcCa51KDjmVzZagDYZSJ7KpqkKLxG2aJAO67+Y2O0k/47H5A71Q4eOMDOj /cpoNEZB5y+nLbzQ07zHdoyiBOAkA0U5Ku6iUXF+Sb5JCO0w984LdjQ9M8Ll42tq04jO V2TBLFo54V07e8iPelizoBjbldJxs81qzR+m+bhy+VzckVkvLaWWqMjqBtBFRP5nPfCr LZk90P0U2vNIInaVJ2nLlrUB+QRgarTVeisfP2uvlnmohAdiLzuM2sennX9t9qoHCOAn 268/ABq1HO20belSNgZGHvJE8WMCbzTtmBv/1bMzHZYDLal/IdAQjJx1N1GUcrt5uCqP ck6Q== 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=yEQ3QDmG4J4aCqR8TE4zPyewDF8Wu8jUX8cEw4gcVRM=; b=sWtzw0cg/rsbzoKgxmbl6DpzAJAIRiSIh5R0HDFkE7B1Pspih4xF2DSJcZkO0qPqFR zZ3dCFZVKzQlp1WywTjYFEs12glq64eXtIwq4IytSW6KoxZFPPtS2Bad11/0IgY3TkGN +qREnmen+8gw2ZAubsCfWogTIYhPMJcwPgz6mhjueuSvuLhirZe3dlUxqcrviTICGaU+ 24TtQto1zNcSaYQUB4r28ALw2oLCZDolNj+xW8CH31dGA3nrzCxkeJ5PdpwtWb13OzgZ de2tUwYNIomwXnXyHjxxGqdesTIOKw9NeY+7OA7JDnSBUt7b/NL4AfwdHiFSrjQglcs/ uk2Q== X-Gm-Message-State: APjAAAWtnfxNxPKAqDhe47Nuxkj7ZAv1LT/tofLZ5XbK98m/nRjoM4HV GspPHw2oFUW4nwpPZuGJFhc= X-Google-Smtp-Source: APXvYqzX9tfEM2lwPbl+tJ2jnH/8uKb0388ddWRDbaD3EtJA24j7l+BR6W/1NtQSeMBgWSe/SSUWEw== X-Received: by 2002:a63:2b0d:: with SMTP id r13mr47971764pgr.400.1557327510091; Wed, 08 May 2019 07:58:30 -0700 (PDT) Received: from [192.168.84.92] (207.sub-166-167-102.myvzw.com. [166.167.102.207]) by smtp.gmail.com with ESMTPSA id h6sm11452931pfk.188.2019.05.08.07.58.27 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Wed, 08 May 2019 07:58:29 -0700 (PDT) Subject: Re: [PATCH v2] netfilter: xt_owner: Add supplementary groups option To: Lukasz Pawelczyk , Pablo Neira Ayuso , Jozsef Kadlecsik , Florian Westphal , "David S. Miller" , netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Lukasz Pawelczyk References: <20190508141211.4191-1-l.pawelczyk@samsung.com> From: Eric Dumazet Message-ID: <98f71c64-3887-b715-effb-894224a71ef9@gmail.com> Date: Wed, 8 May 2019 07:58:25 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190508141211.4191-1-l.pawelczyk@samsung.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 5/8/19 10:12 AM, Lukasz Pawelczyk wrote: > The XT_SUPPL_GROUPS flag causes GIDs specified with XT_OWNER_GID to > be also checked in the supplementary groups of a process. > > Signed-off-by: Lukasz Pawelczyk > --- > include/uapi/linux/netfilter/xt_owner.h | 1 + > net/netfilter/xt_owner.c | 23 ++++++++++++++++++++--- > 2 files changed, 21 insertions(+), 3 deletions(-) > > diff --git a/include/uapi/linux/netfilter/xt_owner.h b/include/uapi/linux/netfilter/xt_owner.h > index fa3ad84957d5..d646f0dc3466 100644 > --- a/include/uapi/linux/netfilter/xt_owner.h > +++ b/include/uapi/linux/netfilter/xt_owner.h > @@ -8,6 +8,7 @@ enum { > XT_OWNER_UID = 1 << 0, > XT_OWNER_GID = 1 << 1, > XT_OWNER_SOCKET = 1 << 2, > + XT_SUPPL_GROUPS = 1 << 3, > }; > > struct xt_owner_match_info { > diff --git a/net/netfilter/xt_owner.c b/net/netfilter/xt_owner.c > index 46686fb73784..283a1fb5cc52 100644 > --- a/net/netfilter/xt_owner.c > +++ b/net/netfilter/xt_owner.c > @@ -91,11 +91,28 @@ owner_mt(const struct sk_buff *skb, struct xt_action_param *par) > } > > if (info->match & XT_OWNER_GID) { > + unsigned int i, match = false; > kgid_t gid_min = make_kgid(net->user_ns, info->gid_min); > kgid_t gid_max = make_kgid(net->user_ns, info->gid_max); > - if ((gid_gte(filp->f_cred->fsgid, gid_min) && > - gid_lte(filp->f_cred->fsgid, gid_max)) ^ > - !(info->invert & XT_OWNER_GID)) > + struct group_info *gi = filp->f_cred->group_info; > + > + if (gid_gte(filp->f_cred->fsgid, gid_min) && > + gid_lte(filp->f_cred->fsgid, gid_max)) > + match = true; > + > + if (!match && (info->match & XT_SUPPL_GROUPS) && gi) { > + for (i = 0; i < gi->ngroups; ++i) { > + kgid_t group = gi->gid[i]; > + > + if (gid_gte(group, gid_min) && > + gid_lte(group, gid_max)) { > + match = true; > + break; > + } > + } > + } > + > + if (match ^ !(info->invert & XT_OWNER_GID)) > return false; > } > > How can this be safe on SMP ?