From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753749AbcGUQyK (ORCPT ); Thu, 21 Jul 2016 12:54:10 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:49750 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753483AbcGUQxz (ORCPT ); Thu, 21 Jul 2016 12:53:55 -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 11:40:09 -0500 Message-Id: <20160721164014.17534-5-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=1bQHEO-0000M2-Eb;;;mid=<20160721164014.17534-5-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=67.3.204.119;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX19bzy8sybx1pk4Er5j5f0sg1a+hMYoBgaE= 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 * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa03 1397; Body=1 Fuz1=1] X-Spam-DCC: XMission; sa03 1397; Body=1 Fuz1=1 X-Spam-Combo: ;Linux Containers X-Spam-Relay-Country: X-Spam-Timing: total 610 ms - load_scoreonly_sql: 0.05 (0.0%), signal_user_changed: 7 (1.2%), b_tie_ro: 6 (1.0%), parse: 1.37 (0.2%), extract_message_metadata: 26 (4.3%), get_uri_detail_list: 3.0 (0.5%), tests_pri_-1000: 11 (1.7%), tests_pri_-950: 2.0 (0.3%), tests_pri_-900: 1.67 (0.3%), tests_pri_-400: 33 (5.4%), check_bayes: 31 (5.1%), b_tokenize: 13 (2.2%), b_tok_get_all: 7 (1.2%), b_comp_prob: 3.5 (0.6%), b_tok_touch_all: 3.6 (0.6%), b_finish: 0.84 (0.1%), tests_pri_0: 517 (84.7%), check_dkim_signature: 1.15 (0.2%), check_dkim_adsp: 5 (0.9%), tests_pri_500: 6 (1.0%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH v2 05/10] pidns: Add a limit on the number of pid 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/pid_namespace.c | 22 ++++++++++++++++++---- kernel/user_namespace.c | 1 + 3 files changed, 20 insertions(+), 4 deletions(-) diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index f74a0facc696..47733637741a 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -24,6 +24,7 @@ struct uid_gid_map { /* 64 bytes -- 1 cache line */ enum ucounts { UCOUNT_USER_NAMESPACES, + UCOUNT_PID_NAMESPACES, UCOUNT_COUNTS, }; diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index a65ba137fd15..049cc14ae37a 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -79,6 +79,16 @@ static void proc_cleanup_work(struct work_struct *work) /* MAX_PID_NS_LEVEL is needed for limiting size of 'struct pid' */ #define MAX_PID_NS_LEVEL 32 +static bool inc_pid_namespaces(struct user_namespace *ns) +{ + return inc_ucount(ns, UCOUNT_PID_NAMESPACES); +} + +static void dec_pid_namespaces(struct user_namespace *ns) +{ + dec_ucount(ns, UCOUNT_PID_NAMESPACES); +} + static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns, struct pid_namespace *parent_pid_ns) { @@ -87,15 +97,16 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns int i; int err; - if (level > MAX_PID_NS_LEVEL) { - err = -EINVAL; + err = -EINVAL; + if (level > MAX_PID_NS_LEVEL) + goto out; + if (!inc_pid_namespaces(user_ns)) goto out; - } err = -ENOMEM; ns = kmem_cache_zalloc(pid_ns_cachep, GFP_KERNEL); if (ns == NULL) - goto out; + goto out_dec; ns->pidmap[0].page = kzalloc(PAGE_SIZE, GFP_KERNEL); if (!ns->pidmap[0].page) @@ -129,6 +140,8 @@ out_free_map: kfree(ns->pidmap[0].page); out_free: kmem_cache_free(pid_ns_cachep, ns); +out_dec: + dec_pid_namespaces(user_ns); out: return ERR_PTR(err); } @@ -146,6 +159,7 @@ static void destroy_pid_namespace(struct pid_namespace *ns) ns_free_inum(&ns->ns); for (i = 0; i < PIDMAP_ENTRIES; i++) kfree(ns->pidmap[i].page); + dec_pid_namespaces(ns->user_ns); put_user_ns(ns->user_ns); call_rcu(&ns->rcu, delayed_free_pidns); } diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 728d7e4995ff..02a03ead7afc 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -77,6 +77,7 @@ static int count_max = COUNT_MAX; } static struct ctl_table userns_table[] = { UCOUNT_ENTRY("max_user_namespaces"), + UCOUNT_ENTRY("max_pid_namespaces"), { } }; #endif /* CONFIG_SYSCTL */ -- 2.8.3