Date: Mon, 11 Apr 2016 11:47:14 -0700 From: Kees Cook <keescook@...omium.org> To: Geert Uytterhoeven <geert@...ux-m68k.org> Cc: James Morse <james.morse@....com>, Linus Torvalds <torvalds@...ux-foundation.org>, 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>, "Rafael J. Wysocki" <rjw@...ysocki.net>, Len Brown <len.brown@...el.com>, Pavel Machek <pavel@....cz>, 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] Prefer kASLR over Hibernation On Mon, Apr 11, 2016 at 11:21 AM, Geert Uytterhoeven <geert@...ux-m68k.org> wrote: > On Mon, Apr 11, 2016 at 8:03 PM, Kees Cook <keescook@...omium.org> wrote: >> On Mon, Apr 11, 2016 at 1:00 AM, James Morse <james.morse@....com> wrote: >>> On 06/04/16 20:44, Kees Cook 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. >>> >>> While hibernate isn't yet merged for arm64, it does work with kASLR in v4.6-rc*, >>> it would be a shame to have to choose at boot time, (but that's my problem to >>> fix if/when its merged). >> >> Ah, interesting, so they work together on arm64? (i.e. you've actually >> tested a boot loader that provides the seed for kASLR to operate?) > > Probably the PS3 people can provide us with a good tool to generate a > seed that makes hibernation work all the time ;-) > > https://xkcd.com/221/ :) http://assets.amuniversal.com/321a39e06d6401301d80001dd8b71c47 -Kees -- Kees Cook Chrome OS & Brillo Security
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.