Re: [PATCH] Prefer kASLR over Hibernation

From: Rafael J. Wysocki
Date: Wed Apr 06 2016 - 18:05:08 EST


On Wed, Apr 6, 2016 at 11:56 PM, Ingo Molnar <mingo@xxxxxxxxxx> wrote:
>
> * 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.

Right, I forgot about this one.

Thanks,
Rafael