From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753879AbcGUQzB (ORCPT ); Thu, 21 Jul 2016 12:55:01 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:37863 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753694AbcGUQyG (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 11:40:12 -0500 Message-Id: <20160721164014.17534-8-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=1bQHEX-0000M2-Ao;;;mid=<20160721164014.17534-8-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=67.3.204.119;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX18BFute9eaWOACh16RJ0yJJmI86uPeOu+M= 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 * 0.7 XMSubLong Long Subject * 0.0 TVD_RCVD_IP Message was received from an IP address * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa06 1397; Body=1 Fuz1=1] X-Spam-DCC: XMission; sa06 1397; Body=1 Fuz1=1 X-Spam-Combo: ;Linux Containers X-Spam-Relay-Country: X-Spam-Timing: total 299 ms - load_scoreonly_sql: 0.10 (0.0%), signal_user_changed: 4.5 (1.5%), b_tie_ro: 3.1 (1.0%), parse: 1.02 (0.3%), extract_message_metadata: 13 (4.3%), get_uri_detail_list: 1.48 (0.5%), tests_pri_-1000: 6 (2.2%), tests_pri_-950: 1.33 (0.4%), tests_pri_-900: 1.10 (0.4%), tests_pri_-400: 20 (6.6%), check_bayes: 19 (6.2%), b_tokenize: 6 (2.2%), b_tok_get_all: 6 (2.0%), b_comp_prob: 1.46 (0.5%), b_tok_touch_all: 2.6 (0.9%), b_finish: 0.68 (0.2%), tests_pri_0: 244 (81.6%), check_dkim_signature: 0.54 (0.2%), check_dkim_adsp: 2.9 (1.0%), tests_pri_500: 4.5 (1.5%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH v2 08/10] cgroupns: Add a limit on the number of cgroup 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/cgroup.c | 15 +++++++++++++++ kernel/user_namespace.c | 1 + 3 files changed, 17 insertions(+) diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index 367cf08ff63d..1a3a9cb93277 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_CGROUP_NAMESPACES, UCOUNT_COUNTS, }; diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 86cb5c6e8932..240eec43390b 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -6260,6 +6260,16 @@ void cgroup_sk_free(struct sock_cgroup_data *skcd) /* cgroup namespaces */ +static bool inc_cgroup_namespaces(struct user_namespace *ns) +{ + return inc_ucount(ns, UCOUNT_CGROUP_NAMESPACES); +} + +static void dec_cgroup_namespaces(struct user_namespace *ns) +{ + dec_ucount(ns, UCOUNT_CGROUP_NAMESPACES); +} + static struct cgroup_namespace *alloc_cgroup_ns(void) { struct cgroup_namespace *new_ns; @@ -6281,6 +6291,7 @@ static struct cgroup_namespace *alloc_cgroup_ns(void) void free_cgroup_ns(struct cgroup_namespace *ns) { put_css_set(ns->root_cset); + dec_cgroup_namespaces(ns->user_ns); put_user_ns(ns->user_ns); ns_free_inum(&ns->ns); kfree(ns); @@ -6305,6 +6316,9 @@ struct cgroup_namespace *copy_cgroup_ns(unsigned long flags, if (!ns_capable(user_ns, CAP_SYS_ADMIN)) return ERR_PTR(-EPERM); + if (!inc_cgroup_namespaces(user_ns)) + return ERR_PTR(-ENFILE); + mutex_lock(&cgroup_mutex); spin_lock_bh(&css_set_lock); @@ -6317,6 +6331,7 @@ struct cgroup_namespace *copy_cgroup_ns(unsigned long flags, new_ns = alloc_cgroup_ns(); if (IS_ERR(new_ns)) { put_css_set(cset); + dec_cgroup_namespaces(user_ns); return new_ns; } diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 060d3e099f87..1cf074cb47e2 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_cgroup_namespaces"), { } }; #endif /* CONFIG_SYSCTL */ -- 2.8.3