Re: [RFC PATCH 5/8] KEYS: exec request-key within the requesting task's init namespace

[J. Bruce Fields]

On Fri, Feb 06, 2015 at 09:47:25AM +0800, Ian Kent wrote:
> On Thu, 2015-02-05 at 15:14 +0000, David Howells wrote:
> > 
> > > +	/* If running within a container use the container namespace */
> > > +	if (current->nsproxy->net_ns != &init_net)
> > 
> > Is that a viable check?  Is it possible to have a container that shares
> > networking details?
> 
> That's up for discussion.
> 
> I thought about it and concluded that the check is probably not
> sufficient for any of the cases.
> 
> I left it like that because I'm not sure exactly what the use cases are,
> hoping it promote discussion and here we are.
> 
> I also think the current container environments don't share net
> namespace with the root init net namspace, necessarily, because thy are
> containers, ;)
> 
> TBH I haven't looked at the user space container creation code but I
> expect it could be done that way if it was needed, so the answer is yes
> and no, ;)
> 
> The questions then are do we need to check anything else, and what
> environment should the callback use in the different cases, and what
> other cases might break if we change it?
> 
> For example, should the fs namespace also be checked for all of these
> cases, since we're executing a callback, or is whatever that's set to in
> the container always what's required for locating the executable.

What would be the disadvantage of setting UMH_USE_NS unconditionally
here?

--b.
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