From patchwork Thu May 20 09:22:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 444374 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=-19.1 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, USER_AGENT_GIT autolearn=ham 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 A6FD9C433B4 for ; Thu, 20 May 2021 10:11:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8D35061D8E for ; Thu, 20 May 2021 10:11:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235957AbhETKNQ (ORCPT ); Thu, 20 May 2021 06:13:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:46110 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235286AbhETKLQ (ORCPT ); Thu, 20 May 2021 06:11:16 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8317D61965; Thu, 20 May 2021 09:43:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621503814; bh=SnlLtt0XASlW4bHj5v4Rk5vDUK47wB4CKjWPBGbXPEY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y+zj6zK1L+cQOew3szOVWSNP7NwgZvJP/xP8K8YTupOg/xZKdCMBJ7XGNwReTGJ+q lk2sFK5TpJ+6H1zlnqHJNSrNgTVS9yKgysd6l9RMHBKDsz+Sb6uD1JtI8LVvpDCSUn 5biWr8xD/Cy+Qv0Pf+X31lhPhQSUje3V0+8Fcgso= 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 4.19 391/425] netfilter: conntrack: Make global sysctls readonly in non-init netns Date: Thu, 20 May 2021 11:22:40 +0200 Message-Id: <20210520092144.251440663@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092131.308959589@linuxfoundation.org> References: <20210520092131.308959589@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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 | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -594,8 +594,11 @@ static int nf_conntrack_standalone_init_ if (net->user_ns != &init_user_ns) table[0].procname = NULL; - if (!net_eq(&init_net, net)) + if (!net_eq(&init_net, net)) { + table[0].mode = 0444; table[2].mode = 0444; + table[5].mode = 0444; + } net->ct.sysctl_header = register_net_sysctl(net, "net/netfilter", table); if (!net->ct.sysctl_header)