Re: [PATCH][BUGFIX] cgroups: fix pid namespace bug

["Serge E. Hallyn" <serue@us.ibm.com>]

Quoting Paul Menage (menage@google.com):
> On Thu, Jul 2, 2009 at 9:37 AM, Serge E. Hallyn<serue@us.ibm.com> wrote:
> >
> >        1. the only way it won't outlive the open file is if the
> >                task opens the file, hands the open fd over a
> >                unix socket, then exits as the last task of its
> >                pidns
> 
> Right.
> 
> >        2. We don't dereference the pid_ns, so there is no actual
> >                safety issue.  So it would become a problem only
> >                if a new pidns gets created at that same address
> 
> Which is fairly likely given that pid_namespace is allocated from a
> specific cache.
> 
> Paul

The scenario as a whole is still pretty unlikely, but there's just
no reason to risk it.

-serge