From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cyrill Gorcunov <gorcunov@gmail.com>
Subject: Re: [RFC] fs, proc: Introduce the /proc/<pid>/map_files/ directory v2
Date: Thu, 25 Aug 2011 18:30:04 +0400
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Cc: Pavel Emelyanov <xemul@parallels.com>, Zan Lynx <zlynx@acm.org>,
	Nathan Lynch <ntl@pobox.com>,
	Oren Laadan <orenl@cs.columbia.edu>,
	Daniel Lezcano <dlezcano@fr.ibm.com>,
	Tejun Heo <tj@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
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	"containers@lists.osdl.org" <containers@lists.osdl.org>,
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	Serge Hallyn <serge.hallyn@canonical.com>,
	LINUXFS-ML <linux-fsdevel@vger.kernel.org>,
	James Bottomley <jbottomley@parallels.com>
To: Andi Kleen <andi@firstfloor.org>
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On Thu, Aug 25, 2011 at 04:04:35PM +0200, Andi Kleen wrote:
...
> > > 
> > > For example if I pass a file descriptor into a chroot process for
> > > reading, and with this interface you can open it for writing too.
> > > I could see this causing problems.
> > 
> > How does it differ from the /proc/pid/fd links?
> 
> Those cannot be opened I thought.
> -Andi
> 

We have ptrace_may_access in lookup so I don't think you'll be
able to open it from another namespace or/and if you have not
enough credentials to.

	Cyrill