[kernel-hardening] Re: [PATCH] Prefer kASLR over Hibernation

[Ingo Molnar <mingo@kernel.org>]

* Kees Cook <keescook@chromium.org> wrote:

> >> I don't think this is a good idea, as it turns off emergency hibernation of 
> >> laptops - many desktop distros support it by default.
> >
> > Right, I forgot about this one.
> 
> When I last checked Ubuntu doesn't enable hibernation by default any more: 
> https://help.ubuntu.com/16.04/ubuntu-help/power-hibernate.html
> 
> And it seems like Fedora either doesn't either, or has a lot of people
> for whom it doesn't work:
> https://bugzilla.redhat.com/show_bug.cgi?id=1206936
> https://bugzilla.redhat.com/show_bug.cgi?id=1224151
> http://blog.kriptonium.com/2015/12/fedora-23-hibernate.html

Ok, that's a relatively recent development, I distinctly remember my laptop being 
hibernated in such a fashion fairly recently.

That makes it easier to hack around the kASLR incompatibility by making 
hibernation less useful. Personally I think that conceptually user space 
persistency (CRIU et al) is superior to kernel level hibernation - but
user-space save/restore is nowhere near as complete as kernel hibernation,
so it's still somewhat sad that it doesn't work ...

Thanks,

	Ingo