From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH] Prefer kASLR over Hibernation Date: Wed, 6 Apr 2016 22:17:16 +0200 Message-ID: <20160406201716.GA14241@amd> References: <20160406194404.GA11150@www.outflux.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20160406194404.GA11150@www.outflux.net> Sender: linux-doc-owner@vger.kernel.org To: Kees Cook Cc: Linus Torvalds , Ard Biesheuvel , Matt Redfearn , Yves-Alexis Perez , Emrah Demir , Jonathan Corbet , x86@kernel.org, "Rafael J. Wysocki" , Len Brown , Borislav Petkov , Andy Lutomirski , linux-doc@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com List-Id: linux-pm@vger.kernel.org Hi! > 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. I must say I don't exactly like this patch. Why is kASLR incompatible with hibernation? We can hibernate have 4.3 kernel resume hibernation image of 4.2 kernel (on x86-64, and I have patches for x86). Resuming kernel with different randomization does not look that much different... Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html