Messages in this thread | | | Subject | Re: [PATCH] exit: PR_SET_ANCHOR for marking processes as reapers for child processes | From | (Eric W. Biederman) | Date | Wed, 10 Mar 2010 20:14:55 -0800 |
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Lennart Poettering <mzxreary@0pointer.de> writes:
> On Thu, 04.03.10 15:08, Oleg Nesterov (oleg@redhat.com) wrote: > >> Should we clear ->child_anchor flags when the "sub-init" execs? Or, >> at least, when the task changes its credentials? Probably not, but >> dunno. > > Since this flag is only useful for a very well defined type of processes > (i.e. session managers, supervising daemons, init systems) it might make > sense to reset it automatically when privs are dropped or we exec > something. After all, I don't see how we'd gain any useful functionality > when we allow this flag to continue to be set. However we would > certainly be on the safer side when we reset it, because that way it can > never leak it to processes that are differently privileged or do not > expect it. > > So, for the sake of being on the safe side, I think we should reset the > flag on exec()/setuid(). > >> It is a bit strange that PR_SET_ANCHOR acts per-thread, not per >> process. > > Yes, I agree, this should be per-process indeed.
Have you take a look at the pid namespace?
Except for the fact it requires privilege to create it seems to do what you want. It is certainly what I have been using when I want an inescapable environment.
If nothing else I get the feeling that what you are after is a generalization of the child_reaper feature in the pid namespace and yet you haven't touched any of that code.
Eric
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