Messages in this thread | | | Date | Tue, 16 Jul 2013 21:39:00 +0000 | From | "Serge E. Hallyn" <> | Subject | Re: [PATCH RFC] allow some kernel filesystems to be mounted in a user namespace |
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Quoting Serge E. Hallyn (serge@hallyn.com): > Quoting Andy Lutomirski (luto@amacapital.net): > > On 07/16/2013 12:50 PM, Serge E. Hallyn wrote: > > > Quoting Al Viro (viro@ZenIV.linux.org.uk): > > >> On Tue, Jul 16, 2013 at 02:29:20PM -0500, Serge Hallyn wrote: > > >>> All the files will be owned by host root, so there's no security > > >>> concern in allowing this. > > >> > > >> Files owned by root != very bad things can't be done by non-root. > > >> Especially for debugfs, which is very much a "don't even think about > > >> mounting that on a production box" thing... > > > > > > I would prefer it not be mounted. But near as I can tell there > > > should be no regression security-wise whether an unprivileged > > > user on the host has access to it, or whether a user in a > > > non-init user ns is allowed to mount it. (Obviously I could very > > > well be wrong) > > > > I would argue that either (a) debugfs denies everything to non-root, so > > mounting it in a (rootless) userns is useless or (b) it doesn't, in > > which case it's dangerous. > > > > In neither case does it make sense to me to allow the mount. > > It makes sense from the POV of having sane user-space. I can obviously > work around this by tweaking a stock container rootfs to be different > from a stock host rootfs. It is undesirable.
(s/It/But that/)
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