Messages in this thread | | | Date | Tue, 16 Jul 2013 14:33:01 -0700 | From | Andy Lutomirski <> | Subject | Re: [PATCH RFC] allow some kernel filesystems to be mounted in a user namespace |
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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.
--Andy
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