From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934647Ab3BNO14 (ORCPT ); Thu, 14 Feb 2013 09:27:56 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:59847 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933950Ab3BNO1y (ORCPT ); Thu, 14 Feb 2013 09:27:54 -0500 Date: Thu, 14 Feb 2013 08:27:45 -0600 From: Serge Hallyn To: Glauber Costa Cc: linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, "Eric W. Biederman" , Andrew Morton Subject: Re: [PATCH] kernel: allow reboots from user_ns Message-ID: <20130214142745.GA4470@sergelap> References: <1360843000-31228-1-git-send-email-glommer@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1360843000-31228-1-git-send-email-glommer@parallels.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Quoting Glauber Costa (glommer@parallels.com): > Reboot support for pid namespaces is already implemented and it works > well. However, in most containers the tasks will join all namespaces, > including the now supported user namespace. In that situation, we will > fail the "capable" test and won't be able to reboot. > > The proposed solution is to allow reboots for CAP_SYS_BOOT processes > in the user namespace that owns the pid namespace. > > Signed-off-by: Glauber Costa Note Li Zefan sent this identical patch last year. It's in my own built userns kernel, and definately required :) In any case, Acked-by: Serge E. Hallyn > Cc: Eric W. Biederman > Cc: Andrew Morton > --- > kernel/sys.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/kernel/sys.c b/kernel/sys.c > index 265b376..3b0958e 100644 > --- a/kernel/sys.c > +++ b/kernel/sys.c > @@ -435,9 +435,10 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, > { > char buffer[256]; > int ret = 0; > + struct pid_namespace *curr_pidns = task_active_pid_ns(current); > > /* We only trust the superuser with rebooting the system. */ > - if (!capable(CAP_SYS_BOOT)) > + if (!ns_capable(curr_pidns->user_ns, CAP_SYS_BOOT)) > return -EPERM; > > /* For safety, we require "magic" arguments. */ > @@ -453,7 +454,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, > * pid_namespace, the command is handled by reboot_pid_ns() which will > * call do_exit(). > */ > - ret = reboot_pid_ns(task_active_pid_ns(current), cmd); > + ret = reboot_pid_ns(curr_pidns, cmd); > if (ret) > return ret; > > -- > 1.8.1.2 > > _______________________________________________ > Containers mailing list > Containers@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/containers