From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753961AbcGUQ4E (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 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 X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 TVD_RCVD_IP Message was received from an IP address * 0.7 XMSubLong Long Subject * 1.2 LotsOfNums_01 BODY: Lots of long strings of numbers * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa07 1397; Body=1 Fuz1=1] X-Spam-DCC: XMission; sa07 1397; Body=1 Fuz1=1 X-Spam-Combo: *;Linux Containers X-Spam-Relay-Country: X-Spam-Timing: total 293 ms - load_scoreonly_sql: 0.04 (0.0%), signal_user_changed: 5 (1.7%), b_tie_ro: 4.0 (1.4%), parse: 0.69 (0.2%), extract_message_metadata: 12 (4.0%), get_uri_detail_list: 1.46 (0.5%), tests_pri_-1000: 6 (1.9%), tests_pri_-950: 1.08 (0.4%), tests_pri_-900: 0.96 (0.3%), tests_pri_-400: 22 (7.4%), check_bayes: 21 (7.0%), b_tokenize: 6 (2.0%), b_tok_get_all: 6 (2.0%), b_comp_prob: 1.53 (0.5%), b_tok_touch_all: 2.8 (0.9%), b_finish: 0.64 (0.2%), tests_pri_0: 240 (82.1%), check_dkim_signature: 0.47 (0.2%), check_dkim_adsp: 3.1 (1.0%), tests_pri_500: 3.3 (1.1%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH v2 09/10] netns: Add a limit on the number of net namespaces X-Spam-Flag: No 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-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Signed-off-by: "Eric W. Biederman" --- 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); } -- 2.8.3