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Date: Tue, 9 Mar 2010 22:49:41 +0000
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: ebiederm@xmission.com (Eric W. Biederman)
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
       Ingo Molnar <mingo@elte.hu>, James Morris <jmorris@namei.org>,
       linux-kernel@vger.kernel.org, Kyle McMartin <kyle@mcmartin.ca>,
       Alexander Viro <viro@ftp.linux.org.uk>
Subject: Re: Upstream first policy
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> time.  If pathnames were not fundamentally important we could apply
> a patch like the one below and allow unprivileged users to unshare
> the mount namespace and mount filesystems wherever.  There is nothing
> fundamental about those operations that require root privileges except
> that you are manipulating the pathnames of objects.

And in a purely SELinux enviromnment your patch would work out because
you could use labels to control this stuff.
 

> -	if (!capable(CAP_SYS_ADMIN))
> -		return -EPERM;
> -

It does raise the question about whether you can do it if you had a
namespace property of "ignore suidness". I'm not sure thats enough
however.