From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753019Ab2APAiN (ORCPT ); Sun, 15 Jan 2012 19:38:13 -0500 Received: from mail-iy0-f174.google.com ([209.85.210.174]:48333 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752904Ab2APAhw (ORCPT ); Sun, 15 Jan 2012 19:37:52 -0500 From: Andy Lutomirski To: Casey Schaufler , Linus Torvalds Cc: Jamie Lokier , Will Drewry , linux-kernel@vger.kernel.org, keescook@chromium.org, john.johansen@canonical.com, serge.hallyn@canonical.com, coreyb@linux.vnet.ibm.com, pmoore@redhat.com, eparis@redhat.com, djm@mindrot.org, segoon@openwall.com, rostedt@goodmis.org, jmorris@namei.org, scarybeasts@gmail.com, avi@redhat.com, penberg@cs.helsinki.fi, viro@zeniv.linux.org.uk, mingo@elte.hu, akpm@linux-foundation.org, khilman@ti.com, borislav.petkov@amd.com, amwang@redhat.com, oleg@redhat.com, ak@linux.intel.com, eric.dumazet@gmail.com, gregkh@suse.de, dhowells@redhat.com, daniel.lezcano@free.fr, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org, olofj@chromium.org, mhalcrow@google.com, dlaor@redhat.com, corbet@lwn.net, alan@lxorguk.ukuu.org.uk, Andy Lutomirski Subject: [PATCH v2 3/4] Allow unprivileged CLONE_NEWUTS and CLONE_NEWIPC with no_new_privs Date: Sun, 15 Jan 2012 16:37:20 -0800 Message-Id: <7b13e7dbe19369a01d2eee793b01df9da4ff100b.1326673414.git.luto@amacapital.net> X-Mailer: git-send-email 1.7.7.5 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org They are normally disallowed because they could be used to subvert setuid programs. But if setuid is disabled, then they are safe. Signed-off-by: Andy Lutomirski --- kernel/nsproxy.c | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-) diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index 9aeab4b..471f4a3 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -191,7 +191,13 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags, CLONE_NEWNET))) return 0; - if (!capable(CAP_SYS_ADMIN)) + /* We require either no_new_privs or CAP_SYS_ADMIN for all modes */ + if (!current->no_new_privs && !capable(CAP_SYS_ADMIN)) + return -EPERM; + + /* NEWNS and NEWNET always require CAP_SYS_ADMIN. */ + if ((unshare_flags & (CLONE_NEWNS | CLONE_NEWNET)) && + !capable(CAP_SYS_ADMIN)) return -EPERM; *new_nsp = create_new_namespaces(unshare_flags, current, -- 1.7.7.5