From patchwork Thu Jul 21 16:40:13 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 9242019 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id BD41060574 for ; Thu, 21 Jul 2016 16:57:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AE65E22380 for ; Thu, 21 Jul 2016 16:57:39 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A2EF21FF27; Thu, 21 Jul 2016 16:57:39 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E0B4822380 for ; Thu, 21 Jul 2016 16:57:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753564AbcGUQ4E (ORCPT ); Thu, 21 Jul 2016 12:56:04 -0400 Received: from out03.mta.xmission.com ([166.70.13.233]:40974 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753687AbcGUQyG (ORCPT ); Thu, 21 Jul 2016 12:54:06 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]) by out03.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1bQHEa-0000TL-Pr; Thu, 21 Jul 2016 10:54:04 -0600 Received: from 67-3-204-119.omah.qwest.net ([67.3.204.119] helo=x220.int.ebiederm.org) by in02.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1bQHEa-0000M2-0D; Thu, 21 Jul 2016 10:54:04 -0600 From: "Eric W. Biederman" To: Linux Containers Cc: Andy Lutomirski , Jann Horn , Kees Cook , Nikolay Borisov , "Serge E. Hallyn" , Seth Forshee , linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, "Eric W. Biederman" Date: Thu, 21 Jul 2016 11:40:13 -0500 Message-Id: <20160721164014.17534-9-ebiederm@xmission.com> X-Mailer: git-send-email 2.8.3 In-Reply-To: <20160721164014.17534-1-ebiederm@xmission.com> References: <87d1m754jc.fsf@x220.int.ebiederm.org> <20160721164014.17534-1-ebiederm@xmission.com> X-XM-SPF: eid=1bQHEa-0000M2-0D; ; ; mid=<20160721164014.17534-9-ebiederm@xmission.com>; ; ; hst=in02.mta.xmission.com; ; ; ip=67.3.204.119; ; ; frm=ebiederm@xmission.com; ; ; spf=neutral X-XM-AID: U2FsdGVkX1+kUS5U8bqhO2MUj48gyG8jYEYlqQjutEY= X-SA-Exim-Connect-IP: 67.3.204.119 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 09/10] netns: Add a limit on the number of net namespaces X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Signed-off-by: "Eric W. Biederman" Acked-by: Serge Hallyn --- include/linux/user_namespace.h | 1 + kernel/user_namespace.c | 1 + net/core/net_namespace.c | 15 +++++++++++++++ 3 files changed, 17 insertions(+) diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index 1a3a9cb93277..f86afa536baf 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -27,6 +27,7 @@ enum ucounts { UCOUNT_PID_NAMESPACES, UCOUNT_UTS_NAMESPACES, UCOUNT_IPC_NAMESPACES, + UCOUNT_NET_NAMESPACES, UCOUNT_CGROUP_NAMESPACES, UCOUNT_COUNTS, }; diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 1cf074cb47e2..e326ca722ae0 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -80,6 +80,7 @@ static struct ctl_table userns_table[] = { UCOUNT_ENTRY("max_pid_namespaces"), UCOUNT_ENTRY("max_uts_namespaces"), UCOUNT_ENTRY("max_ipc_namespaces"), + UCOUNT_ENTRY("max_net_namespaces"), UCOUNT_ENTRY("max_cgroup_namespaces"), { } }; diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 2c2eb1b629b1..a489f192d619 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -266,6 +266,16 @@ struct net *get_net_ns_by_id(struct net *net, int id) return peer; } +static bool inc_net_namespaces(struct user_namespace *ns) +{ + return inc_ucount(ns, UCOUNT_NET_NAMESPACES); +} + +static void dec_net_namespaces(struct user_namespace *ns) +{ + dec_ucount(ns, UCOUNT_NET_NAMESPACES); +} + /* * setup_net runs the initializers for the network namespace object. */ @@ -276,6 +286,9 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns) int error = 0; LIST_HEAD(net_exit_list); + if (!inc_net_namespaces(user_ns)) + return -ENFILE; + atomic_set(&net->count, 1); atomic_set(&net->passive, 1); net->dev_base_seq = 1; @@ -372,6 +385,7 @@ struct net *copy_net_ns(unsigned long flags, } mutex_unlock(&net_mutex); if (rv < 0) { + dec_net_namespaces(user_ns); put_user_ns(user_ns); net_drop_ns(net); return ERR_PTR(rv); @@ -444,6 +458,7 @@ static void cleanup_net(struct work_struct *work) /* Finally it is safe to free my network namespace structure */ list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) { list_del_init(&net->exit_list); + dec_net_namespaces(net->user_ns); put_user_ns(net->user_ns); net_drop_ns(net); }