Re: [patch 0/8] unprivileged mount syscall

Miklos Szeredi
2007-04-09T20:15:18Z

> > One thing that is missing from this series is the ability to restrict
> > user mounts to private namespaces. The reason is that private
> > namespaces have still not gained the momentum and support needed for
> > painless user experience. So such a feature would not yet get enough
> > attention and testing. However adding such an optional restriction
> > can be done with minimal changes in the future, once private
> > namespaces have matured.
>
> What is the main reason for that feature? Would it be to prevent things
> like login from being tricked by user mounts? Isn't it sufficient, in
> fact, better, to require that the target of the mount be owned by the
> user doing the mount?

It's been discussed later in that thread. Basically you can fool a
lot of system programs (like backup) with mounting/binding in the
global namespace. Restricting the destination doesn't always help.

Miklos