Re: [RESEND PATCH v4 0/3] proc: Relax check of mount visibility

2021-03-10 Thread Alexey Gladkov
On Mon, Feb 22, 2021 at 09:44:40AM -0600, Eric W. Biederman wrote:
> Alexey Gladkov  writes:
> 
> > If only the dynamic part of procfs is mounted (subset=pid), then there is no
> > need to check if procfs is fully visible to the user in the new user
> > namespace.
> 
> 
> A couple of things.
> 
> 1) Allowing the mount should come in the last patch.  So we don't have a
> bisect hazard.
> 
> 2) We should document that we still require a mount of proc to match on
> atime and readonly mount attributes.

Ok. I will try to do it in v5.

> 3) If we can find a way to safely not require a previous mount of proc
> this will be much more valuable.

True, but for now I have no idea how to do it. I would prefer to move in
small steps.

-- 
Rgrds, legion



Re: [RESEND PATCH v4 0/3] proc: Relax check of mount visibility

2021-02-22 Thread Eric W. Biederman
Alexey Gladkov  writes:

> If only the dynamic part of procfs is mounted (subset=pid), then there is no
> need to check if procfs is fully visible to the user in the new user
> namespace.


A couple of things.

1) Allowing the mount should come in the last patch.  So we don't have a
bisect hazard.

2) We should document that we still require a mount of proc to match on
atime and readonly mount attributes.

3) If we can find a way to safely not require a previous mount of proc
this will be much more valuable.

Eric