Re: [RFC][PATCH] rbind across namespaces

Jamie Lokier
2005-05-24T21:51:27Z

Mike Waychison wrote:
> > 1. Deny access to /proc/NNN/fd/, /proc/NNN/cwd, /proc/NNN/root
> > if task NNN cannot be ptraced.
> >
> > 3. Allow entry to /proc/NNN/fd/, /proc/NNN/cwd, /proc/NNN/root
> > if ptrace is allowed; the namespace being irrelevant.
> >
> > 3. Use _exactly_ the same condition as for ptracing,
> > i.e. MAY_PTRACE in fs/proc/base.c. Ensure that condition is
> > consistent with the tests in kernel/ptrace.c, possibly putting
> > the condition in a common header file to keep it consistent in
> > future.
> >
> > 4. If further restrictions are desired, to make namespaces more
> > strict, those should be implemented by further restrictions on
> > which tasks are allowed to ptrace other tasks.
> >
>
> Indeed. A combination of MAY_PTRACE ||ed with a check against current
> sounds reasonable to me.

Note that MAY_PTRACE already includes a check against current.

-- Jamie