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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 5A516C43460 for ; Wed, 5 May 2021 12:07:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 287C0613BA for ; Wed, 5 May 2021 12:07:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233664AbhEEMIY (ORCPT ); Wed, 5 May 2021 08:08:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:47482 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231995AbhEEMHg (ORCPT ); Wed, 5 May 2021 08:07:36 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 519B1610A2; Wed, 5 May 2021 12:06:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620216399; bh=jfsNba7U9iA8JZj5ycsqVMIeZBeB2IQaEFt7ctlUEek=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fkBT7OhZ3iCUiG9jJQYEiknRiHXmqOuIshnCHLBV8cprMe1SrXE6ruy4hlvWz7IfU IMqO5MnJeK921l9ci8mnmSkxeTmn4iwX7bgOtIBuoXJb7XihzAV7p+gMYfeeWW+Ixq ZLG1A/8nN+02zkH1kWhSDBlJ9AN0G7kCxq2487xc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jonathon Reinhart , "David S. Miller" Subject: [PATCH 5.10 02/29] netfilter: conntrack: Make global sysctls readonly in non-init netns Date: Wed, 5 May 2021 14:05:05 +0200 Message-Id: <20210505112326.279633427@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210505112326.195493232@linuxfoundation.org> References: <20210505112326.195493232@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jonathon Reinhart commit 2671fa4dc0109d3fb581bc3078fdf17b5d9080f6 upstream. These sysctls point to global variables: - NF_SYSCTL_CT_MAX (&nf_conntrack_max) - NF_SYSCTL_CT_EXPECT_MAX (&nf_ct_expect_max) - NF_SYSCTL_CT_BUCKETS (&nf_conntrack_htable_size_user) Because their data pointers are not updated to point to per-netns structures, they must be marked read-only in a non-init_net ns. Otherwise, changes in any net namespace are reflected in (leaked into) all other net namespaces. This problem has existed since the introduction of net namespaces. The current logic marks them read-only only if the net namespace is owned by an unprivileged user (other than init_user_ns). Commit d0febd81ae77 ("netfilter: conntrack: re-visit sysctls in unprivileged namespaces") "exposes all sysctls even if the namespace is unpriviliged." Since we need to mark them readonly in any case, we can forego the unprivileged user check altogether. Fixes: d0febd81ae77 ("netfilter: conntrack: re-visit sysctls in unprivileged namespaces") Signed-off-by: Jonathon Reinhart Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/netfilter/nf_conntrack_standalone.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -1060,16 +1060,10 @@ static int nf_conntrack_standalone_init_ nf_conntrack_standalone_init_dccp_sysctl(net, table); nf_conntrack_standalone_init_gre_sysctl(net, table); - /* Don't allow unprivileged users to alter certain sysctls */ - if (net->user_ns != &init_user_ns) { + /* Don't allow non-init_net ns to alter global sysctls */ + if (!net_eq(&init_net, net)) { table[NF_SYSCTL_CT_MAX].mode = 0444; table[NF_SYSCTL_CT_EXPECT_MAX].mode = 0444; - table[NF_SYSCTL_CT_HELPER].mode = 0444; -#ifdef CONFIG_NF_CONNTRACK_EVENTS - table[NF_SYSCTL_CT_EVENTS].mode = 0444; -#endif - table[NF_SYSCTL_CT_BUCKETS].mode = 0444; - } else if (!net_eq(&init_net, net)) { table[NF_SYSCTL_CT_BUCKETS].mode = 0444; }