[PATCH] userns,pidns: Verify the userns for new pid namespaces
Eric W. Biederman
ebiederm at xmission.com
Sun Apr 30 04:42:17 UTC 2017
ebiederm at xmission.com (Eric W. Biederman) writes:
> "Serge E. Hallyn" <serge at hallyn.com> writes:
>> Quoting Eric W. Biederman (ebiederm at xmission.com):
>>> It is pointless and confusing to allow a pid namespace hierarchy and
>>> the user namespace hierarchy to get out of sync. The owner of a child
>>> pid namespace should be the owner of the parent pid namespace or
>>> a descendant of the owner of the parent pid namespace.
>>> Otherwise it is possible to construct scenarios where it is legal to
>>> do something in a parent pid namespace but in a child pid namespace.
>> did you mean 'but not in a child...' above?
> Actually I believe I meant:
>>> Otherwise it is possible to construct scenarios where it is not legal
>>> to do something in a parent pid namespace but it is legal a child pid
> I definitely need to fix that wording thank you.
Looking at some more I mean:
Otherwise it is possible to construct scenarios where a process has a
capability in a over a parent pid namespace but does not have the
capability over a child pid namespace. Which confusingly makes
permission checks non-transitive.
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