Re: [RCF] [PATCH] unprivileged mount/umount

[Eric Van Hensbergen <ericvh@gmail.com>]

On 5/11/05, Jamie Lokier <jamie@shareable.org> wrote:
> 
> Please read carefully: I've described what _current_ kernels do.
> 

I guess I misread when you wrote:

>>
>>You can't do a lot with the new namespace, because of the security
>>restrictions on mount() on a foreign namespace.  That's what I meant
>>about the "small fixes" - get rid of the current->namespace checks and
>>it'll be usable.
>>
>>I don't see the purpose of current->namespace and the associated mount
>>restrictions at all.  I asked Al Viro what it's for, but haven't seen
>>a reply :(  IMHO current->namespace should simply be removed, because the
>>"current namespace" is represented just fine by
>>current->fs->rootmnt->mnt_namespace.
>>

That sounds an awful lot like you want to make changes to the current
support in the kernel.

> It's a poorly understood area of the kernel, and I'm attempting to
> clarify it.  This talk of new system calls for entering a namespace
> makes no sense when you can _already_ do some things that people
> haven't realised the kernel does.
> 

IMHO part of the reason its so poorly understood is that people aren't
using it.  That's why I suggest we use some of the proposed patches
which open up name space operations to common users.  There are some
security checks (like the one brought up justifying the CAP_SYS_ADMIN
permissions on CLONE_NS) that need to be added, before we start
removing others -- and I'm quite concerned that Viro hasn't weighed in
on any of these new patches, I wonder if its because this thread seems
to have gone off the deep end.

          -eric