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From: Al Viro <viro@ZenIV.linux.org.uk>
To: Andrey Vagin <avagin@openvz.org>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-api@vger.kernel.org, Andrey Vagin <avagin@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Cyrill Gorcunov <gorcunov@openvz.org>,
	Pavel Emelyanov <xemul@parallels.com>,
	Serge Hallyn <serge.hallyn@canonical.com>,
	Rob Landley <rob@landley.net>
Subject: Re: [PATCH] [RFC] mnt: add ability to clone mntns starting with the current root
Date: Tue, 7 Oct 2014 14:30:40 +0100	[thread overview]
Message-ID: <20141007133039.GG7996@ZenIV.linux.org.uk> (raw)
In-Reply-To: <1412683977-29543-1-git-send-email-avagin@openvz.org>

On Tue, Oct 07, 2014 at 04:12:57PM +0400, Andrey Vagin wrote:
> Another problem is that rootfs can't be hidden from a container, because
> rootfs can't be moved or umounted.

... which is a bug in mntns_install(), AFAICS.

> Here is an example how to get access to rootfs:
> fd = open("/proc/self/ns/mnt", O_RDONLY)
> umount2("/", MNT_DETACH);
> setns(fd, CLONE_NEWNS)
> 
> rootfs may contain data, which should not be avaliable in CT-s.

Indeed.

> I suggest to add ability to create a mount namespace with specified
> mount points. A current task root can be used as a root for the new
> mount namespace.

Yecchh...  Frankly, you are opening a big can of worms - having rootfs
as absolute root of all namespaces simplifies a lot of things in there.

  reply	other threads:[~2014-10-07 13:30 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-07 12:12 [PATCH] [RFC] mnt: add ability to clone mntns starting with the current root Andrey Vagin
2014-10-07 13:30 ` Al Viro [this message]
     [not found]   ` <20141007133039.GG7996-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org>
2014-10-07 13:33     ` Al Viro
     [not found]       ` <20141007133339.GH7996-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org>
2014-10-07 19:44         ` Andrew Vagin
2014-10-07 20:30         ` Eric W. Biederman
2014-10-07 20:46           ` Serge Hallyn
2014-10-07 20:52             ` Eric W. Biederman
     [not found]               ` <87wq8bvbzg.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2014-10-07 21:32                 ` Serge Hallyn
2014-10-07 21:42                   ` Eric W. Biederman
     [not found]                     ` <87zjd7r1z9.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2014-10-07 22:19                       ` Andy Lutomirski
2014-10-07 22:42                         ` Eric W. Biederman
     [not found]                           ` <87h9zfpkm3.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2014-10-07 22:44                             ` Andy Lutomirski
2014-10-07 23:42                               ` Eric W. Biederman
2014-10-07 23:44                                 ` Andy Lutomirski
2014-10-08  0:20                                   ` Eric W. Biederman
     [not found]                                     ` <87vbnvif9e.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2014-10-08  0:25                                       ` Andy Lutomirski
     [not found]           ` <87r3yjy64e.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2014-10-07 21:02             ` Andy Lutomirski
     [not found]               ` <CALCETrXgssZfi3BirQ=K7-vrPyEh5AzFX2pF+yj76Ngi0sf7Yw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-10-07 21:26                 ` Eric W. Biederman
     [not found]                   ` <87siizshav.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2014-10-07 21:38                     ` Andy Lutomirski
     [not found]                       ` <CALCETrWfZwbGCxnUAg0PnM=tN8MGRQkHrJVC42bVF7sdJKXLmw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-10-07 21:50                         ` Eric W. Biederman
     [not found]                           ` <87zjd7pn0o.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2014-10-07 21:52                             ` Andy Lutomirski
2014-10-07 21:33                 ` Serge Hallyn
     [not found] ` <1412683977-29543-1-git-send-email-avagin-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
2014-10-07 20:45   ` Eric W. Biederman
     [not found]     ` <87mw97wqvx.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2014-10-08 11:08       ` Andrew Vagin
     [not found]         ` <20141008110829.GC24908-yYYamFZzV1regbzhZkK2zA@public.gmane.org>
2014-10-08 15:35           ` Andy Lutomirski
     [not found]             ` <CALCETrX4XrgbQNZZa7=1009KqhJ2gT+VBUkC15+59K9yEiTSbQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-10-08 19:23               ` Eric W. Biederman
2014-10-08 19:31                 ` Andy Lutomirski
     [not found]                   ` <CALCETrVSxYr=Oa29qHNL-GoifS26U8TfpreGY+KN7g926YgHUw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-10-08 21:36                     ` Rob Landley
2014-10-08 22:01                       ` Andy Lutomirski
     [not found]                         ` <CALCETrXapWTiFw2CC1m43fs9yuHuesXxXtmHh-5F3J_bUYeRxg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-10-08 23:38                           ` Serge Hallyn
2014-10-08 23:41                             ` Andy Lutomirski
     [not found]                 ` <87vbnue56f.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2014-10-08 21:23                   ` Rob Landley
2014-10-09 10:29                   ` Andrew Vagin

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