[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAGXu5jKNKV2RaPCw+m3R-e7irmmP0eRBBq9RKY0mcH5A1Nsx6g@mail.gmail.com>
Date: Thu, 14 Apr 2016 13:14:07 -0700
From: Kees Cook <keescook@...omium.org>
To: Pavel Machek <pavel@...x.de>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>,
"Rafael J. Wysocki" <rafael@...nel.org>,
Ingo Molnar <mingo@...nel.org>,
James Morse <james.morse@....com>,
Ard Biesheuvel <ard.biesheuvel@...aro.org>,
Matt Redfearn <matt.redfearn@...tec.com>,
Yves-Alexis Perez <corsac@...ian.org>,
Emrah Demir <ed@...sec.com>, Jonathan Corbet <corbet@....net>,
"x86@...nel.org" <x86@...nel.org>, Len Brown <len.brown@...el.com>,
Borislav Petkov <bp@...e.de>,
Andy Lutomirski <luto@...nel.org>,
"linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
Linux PM list <linux-pm@...r.kernel.org>,
LKML <linux-kernel@...r.kernel.org>,
"kernel-hardening@...ts.openwall.com"
<kernel-hardening@...ts.openwall.com>
Subject: Re: [PATCH v2] kaslr: allow kASLR to be default over Hibernation
On Thu, Apr 14, 2016 at 1:01 PM, Pavel Machek <pavel@...x.de> wrote:
> Hi!
>
>> Since kASLR and Hibernation can not currently coexist at runtime
>> on x86, the default behavior was to disable kASLR by default when
>> CONFIG_HIBERNATION was present (to retain original behavior).
>>
>> The behavior of kASLR on arm64 (and soon MIPS) is to be enabled by
>> default when selected at build time. Since arm64 Hibernation does not
>> conflict with kASLR, this fixes the hibernation argument parsing to be
>> x86-specific. Additionally, since end users want to be able to select
>> kASLR on x86 by default at build time, create CONFIG_RANDOMIZE_BASE_ON
>> that is present only on x86.
>>
>> Signed-off-by: Kees Cook <keescook@...omium.org>
>
> I believe this is bad idea. arm64 shows that kaslr and hibernation can
> coexist, and hibernation is still useful when your battery runs out.
What? I'm confused -- this patch leaves the x86 behavior as-is by
default but allows hibernation to work with arm64. (For example, right
now, if you boot arm64 with "kaslr" kernel argument, hibernation will
get needlessly disabled.)
-Kees
--
Kees Cook
Chrome OS & Brillo Security
Powered by blists - more mailing lists