Re: [PATCH v3 0/7] User namespace mount updates

Seth Forshee
2015-11-17T19:21:41Z

On Tue, Nov 17, 2015 at 08:12:31PM +0100, Richard Weinberger wrote:
> On Tue, Nov 17, 2015 at 7:34 PM, Seth Forshee
> <seth.forshee@canonical.com> wrote:
> > On Tue, Nov 17, 2015 at 05:55:06PM +0000, Al Viro wrote:
> >> On Tue, Nov 17, 2015 at 11:25:51AM -0600, Seth Forshee wrote:
> >>
> >> > Shortly after that I plan to follow with support for ext4. I've been
> >> > fuzzing ext4 for a while now and it has held up well, and I'm currently
> >> > working on hand-crafted attacks. Ted has commented privately (to others,
> >> > not to me personally) that he will fix bugs for such attacks, though I
> >> > haven't seen any public comments to that effect.
> >>
> >> _Static_ attacks, or change-image-under-mounted-fs attacks?
> >
> > Right now only static attacks, change-image-under-mounted-fs attacks
> > will be next.
>
> Do we *really* need to enable unprivileged mounting of kernel filesystems?
> What about just enabling fuse and implement ext4 and friends as fuse
> filesystems?
> Using the approaching Linux Kernel Libary[1] this is easy.

I haven't looked at this project, but I'm guessing that programs must be
written specifically to make use of it? I.e. you can't just use the
mount syscall, and thus all existing software still doesn't work?

> [1] https://lkml.org/lkml/2015/11/3/706
> --
> Thanks,
> //richard