Messages in this thread | | | From | (Eric W. Biederman) | Date | Mon, 25 Jul 2016 10:17:15 -0500 | Subject | Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces |
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"Serge E. Hallyn" <serge@hallyn.com> writes:
> Quoting Michael Kerrisk (man-pages) (mtk.manpages@gmail.com): >> Hi Eric, >> >> On 07/25/2016 03:18 PM, Eric W. Biederman wrote: >> >"Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com> writes: >> > >> >>Hi Andrey, >> >> >> >>On 07/22/2016 08:25 PM, Andrey Vagin wrote: >> >>Perhaps add "and the caller does not have CAP_SYS_ADMIN" in the initial >> >>user namespace"? >> > >> >Having looked at that bit of code I don't think capabilities really >> >have a role to play. >> >> Yes, I caught up with that now. I await to see how this plays out >> in the next patch version. > > Thanks - that had caught my eye but I hadn't had time to look into the > justification for this. Hiding this kind of thing indeed seems wrong to > me, unless there is a really good justification for it, i.e. a way > to use that info in an exploit.
To avoid breaking checkpoint/restart we need to limit information to the namespaces the caller is a member of for the user and pid namespaces.
This roughly duplicates the parentage checks in ns_capable.
Conceptually this is the same as limiting .. in a chroot environment.
Eric
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