Re: [PATCH] Prefer kASLR over Hibernation

From: Ingo Molnar
Date: Wed Apr 06 2016 - 17:56:46 EST



* Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote:

> On Wed, Apr 6, 2016 at 9:44 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> > When building with both CONFIG_HIBERNATION and CONFIG_RANDOMIZE_BASE,
> > one or the other must be chosen at boot-time. Until now, hibernation
> > was selected when no choice was made on the command line.
> >
> > To make the security benefits of kASLR more widely available to end
> > users (since the use of hibernation is becoming more rare and kASLR,
> > already available on x86, will be available on arm64 and MIPS soon),
> > this changes the default to preferring kASLR over hibernation. Users
> > wanting hibernation can turn off kASLR by adding "nokaslr" to the kernel
> > command line.
> >
> > Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
>
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> Or do you want me to apply it?

I don't think this is a good idea, as it turns off emergency hibernation of
laptops - many desktop distros support it by default.

Thanks,

Ingo