From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760282AbXGQTeG (ORCPT ); Tue, 17 Jul 2007 15:34:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964801AbXGQTda (ORCPT ); Tue, 17 Jul 2007 15:33:30 -0400 Received: from e32.co.us.ibm.com ([32.97.110.150]:55311 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964790AbXGQTd2 (ORCPT ); Tue, 17 Jul 2007 15:33:28 -0400 Date: Tue, 17 Jul 2007 14:33:27 -0500 From: "Serge E. Hallyn" To: Sukadev Bhattiprolu , Pavel Emelianov Cc: lkml , Andrew Morton , containers@lists.osdl.org, Cedric Le Goater Subject: [PATCH 1/1] user namespace: fix copy_user_ns return value Message-ID: <20070717193327.GA9101@sergelap.austin.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >>From 32f86740d27ef77160e438cd7dc4fcd5df159dd0 Mon Sep 17 00:00:00 2001 From: Serge E. Hallyn Date: Tue, 17 Jul 2007 15:28:17 -0400 Subject: [PATCH 1/1] user namespace: fix copy_user_ns return value When a CONFIG_USER_NS=n and a user tries to unshare some namespace other than the user namespace, the dummy copy_user_ns returns NULL rather than the old_ns. This value then gets assigned to task->nsproxy->user_ns, so that a subsequent setuid, which uses task->nsproxy->user_ns, causes a NULL pointer deref. Fix this by returning old_ns. I believe this is a bug both in -mm and mainline. Signed-off-by: Serge E. Hallyn --- include/linux/user_namespace.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index bb32057..1101b0c 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -49,7 +49,7 @@ static inline struct user_namespace *copy_user_ns(int flags, if (flags & CLONE_NEWUSER) return ERR_PTR(-EINVAL); - return NULL; + return old_ns; } static inline void put_user_ns(struct user_namespace *ns) -- 1.5.1.1.GIT