From patchwork Thu Jul 21 16:40:11 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: 9242013 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 ADF3160574 for ; Thu, 21 Jul 2016 16:57:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9DDFC1FF60 for ; Thu, 21 Jul 2016 16:57:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 92E9627F8C; Thu, 21 Jul 2016 16:57:38 +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=ham 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 0F13827F54 for ; Thu, 21 Jul 2016 16:57:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753984AbcGUQ4d (ORCPT ); Thu, 21 Jul 2016 12:56:33 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:37843 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753652AbcGUQyA (ORCPT ); Thu, 21 Jul 2016 12:54:00 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]) by out02.mta.xmission.com with esmtps (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.82) (envelope-from ) id 1bQHEV-0000tX-B8; Thu, 21 Jul 2016 10:53:59 -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 1bQHEU-0000M2-Np; Thu, 21 Jul 2016 10:53:59 -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 11:40:11 -0500 Message-Id: <20160721164014.17534-7-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=1bQHEU-0000M2-Np; ; ; mid=<20160721164014.17534-7-ebiederm@xmission.com>; ; ; hst=in02.mta.xmission.com; ; ; ip=67.3.204.119; ; ; frm=ebiederm@xmission.com; ; ; spf=neutral X-XM-AID: U2FsdGVkX1/yut5kAOPuhaxrq/i3ezruWnqRNQsHIOU= X-SA-Exim-Connect-IP: 67.3.204.119 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 07/10] ipcns: Add a limit on the number of ipc 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 + ipc/namespace.c | 42 +++++++++++++++++++++++++++++++----------- kernel/user_namespace.c | 1 + 3 files changed, 33 insertions(+), 11 deletions(-) diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index bed2506081fe..367cf08ff63d 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -26,6 +26,7 @@ enum ucounts { UCOUNT_USER_NAMESPACES, UCOUNT_PID_NAMESPACES, UCOUNT_UTS_NAMESPACES, + UCOUNT_IPC_NAMESPACES, UCOUNT_COUNTS, }; diff --git a/ipc/namespace.c b/ipc/namespace.c index 04cb07eb81f1..3996a1e41a1d 100644 --- a/ipc/namespace.c +++ b/ipc/namespace.c @@ -16,33 +16,42 @@ #include "util.h" +static bool inc_ipc_namespaces(struct user_namespace *ns) +{ + return inc_ucount(ns, UCOUNT_IPC_NAMESPACES); +} + +static void dec_ipc_namespaces(struct user_namespace *ns) +{ + dec_ucount(ns, UCOUNT_IPC_NAMESPACES); +} + static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns, struct ipc_namespace *old_ns) { struct ipc_namespace *ns; int err; + err = -ENFILE; + if (!inc_ipc_namespaces(user_ns)) + goto fail; + + err = -ENOMEM; ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL); if (ns == NULL) - return ERR_PTR(-ENOMEM); + goto fail_dec; err = ns_alloc_inum(&ns->ns); - if (err) { - kfree(ns); - return ERR_PTR(err); - } + if (err) + goto fail_free; ns->ns.ops = &ipcns_operations; atomic_set(&ns->count, 1); ns->user_ns = get_user_ns(user_ns); err = mq_init_ns(ns); - if (err) { - put_user_ns(ns->user_ns); - ns_free_inum(&ns->ns); - kfree(ns); - return ERR_PTR(err); - } + if (err) + goto fail_put; atomic_inc(&nr_ipc_ns); sem_init_ns(ns); @@ -50,6 +59,16 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns, shm_init_ns(ns); return ns; + +fail_put: + put_user_ns(ns->user_ns); + ns_free_inum(&ns->ns); +fail_free: + kfree(ns); +fail_dec: + dec_ipc_namespaces(user_ns); +fail: + return ERR_PTR(err); } struct ipc_namespace *copy_ipcs(unsigned long flags, @@ -98,6 +117,7 @@ static void free_ipc_ns(struct ipc_namespace *ns) shm_exit_ns(ns); atomic_dec(&nr_ipc_ns); + dec_ipc_namespaces(ns->user_ns); put_user_ns(ns->user_ns); ns_free_inum(&ns->ns); kfree(ns); diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 6b205c24e888..060d3e099f87 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -79,6 +79,7 @@ static struct ctl_table userns_table[] = { UCOUNT_ENTRY("max_user_namespaces"), UCOUNT_ENTRY("max_pid_namespaces"), UCOUNT_ENTRY("max_uts_namespaces"), + UCOUNT_ENTRY("max_ipc_namespaces"), { } }; #endif /* CONFIG_SYSCTL */