Re: [RFC][PATCH] Fix cap_capable to only allow owners in the parent user namespace to have caps.

[Eric W. Biederman]

"Serge E. Hallyn" <serge@xxxxxxxxxx> writes:

> Quoting Eric W. Biederman (ebiederm@xxxxxxxxxxxx):
>> 
>> Andy Lutomirski pointed out that the current behavior of allowing the
>> owner of a user namespace to have all caps when that owner is not in a
>> parent user namespace is wrong.
>
> To make sure I understand right, the issue is when a uid is mapped
> into multiple namespaces.

Yes.

i.e. uid 1000 in ns1 may own ns2, but uid 1000 in ns3 does not?

I am not certain of your example.

The simple case is:

init_user_ns:
     child_user_ns1 (owned by uid == 0 [in all user namespaces])
           child_user_ns2 (owned by uid == 0 [ in all user namespaces])


root (uid == 0) in child_user_ns2 has all rights over anything in
child_user_ns1.


Thank you for looking.

Eric
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/