From: "H. Peter Anvin" <hpa@zytor.com>
To: Kees Cook <keescook@chromium.org>
Cc: linux-kernel@vger.kernel.org,
kernel-hardening@lists.openwall.com,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, Jarkko Sakkinen <jarkko.sakkinen@intel.com>,
Matthew Garrett <mjg@redhat.com>,
Matt Fleming <matt.fleming@intel.com>,
Eric Northup <digitaleric@google.com>,
Dan Rosenberg <drosenberg@vsecurity.com>,
Julien Tinnes <jln@google.com>, Will Drewry <wad@chromium.org>
Subject: [kernel-hardening] Re: [PATCH 3/3] x86: kernel base offset ASLR
Date: Thu, 04 Apr 2013 13:21:29 -0700 [thread overview]
Message-ID: <515DE0C9.3030709@zytor.com> (raw)
In-Reply-To: <1365106055-22939-4-git-send-email-keescook@chromium.org>
I have to admit to being somewhat skeptical toward KASLR with only 8
bits of randomness. There are at least two potential ways of
dramatically increasing the available randomness:
1. actually compose the kernel of multiple independently relocatable
pieces (maybe chunk it on 2M boundaries or something.)
2. compile the kernel as one of the memory models which can be executed
anywhere in the 64-bit address space. The cost of this would have
to be quantified, of course.
The latter is particularly something that should be considered for the
LPF JIT, to defend against JIT spray attacks.
-hpa
WARNING: multiple messages have this Message-ID (diff)
From: "H. Peter Anvin" <hpa@zytor.com>
To: Kees Cook <keescook@chromium.org>
Cc: linux-kernel@vger.kernel.org,
kernel-hardening@lists.openwall.com,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, Jarkko Sakkinen <jarkko.sakkinen@intel.com>,
Matthew Garrett <mjg@redhat.com>,
Matt Fleming <matt.fleming@intel.com>,
Eric Northup <digitaleric@google.com>,
Dan Rosenberg <drosenberg@vsecurity.com>,
Julien Tinnes <jln@google.com>, Will Drewry <wad@chromium.org>
Subject: Re: [PATCH 3/3] x86: kernel base offset ASLR
Date: Thu, 04 Apr 2013 13:21:29 -0700 [thread overview]
Message-ID: <515DE0C9.3030709@zytor.com> (raw)
In-Reply-To: <1365106055-22939-4-git-send-email-keescook@chromium.org>
I have to admit to being somewhat skeptical toward KASLR with only 8
bits of randomness. There are at least two potential ways of
dramatically increasing the available randomness:
1. actually compose the kernel of multiple independently relocatable
pieces (maybe chunk it on 2M boundaries or something.)
2. compile the kernel as one of the memory models which can be executed
anywhere in the 64-bit address space. The cost of this would have
to be quantified, of course.
The latter is particularly something that should be considered for the
LPF JIT, to defend against JIT spray attacks.
-hpa
next prev parent reply other threads:[~2013-04-04 20:21 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-04 20:07 [kernel-hardening] [PATCH 0/3] kernel ASLR Kees Cook
2013-04-04 20:07 ` Kees Cook
2013-04-04 20:07 ` [kernel-hardening] [PATCH 1/3] x86: routines to choose random kernel base offset Kees Cook
2013-04-04 20:07 ` Kees Cook
2013-04-05 7:24 ` [kernel-hardening] " Ingo Molnar
2013-04-05 7:24 ` Ingo Molnar
2013-04-05 7:36 ` [kernel-hardening] " Ingo Molnar
2013-04-05 7:36 ` Ingo Molnar
2013-04-05 18:15 ` [kernel-hardening] " H. Peter Anvin
2013-04-05 18:15 ` H. Peter Anvin
2013-04-08 5:35 ` [kernel-hardening] " Hasinoliva MIARIMANJATO
2013-04-08 5:35 ` Hasinoliva MIARIMANJATO
2013-04-04 20:07 ` [kernel-hardening] [PATCH 2/3] x86: build reloc tool for both 64 and 32 bit Kees Cook
2013-04-04 20:07 ` Kees Cook
2013-04-05 7:13 ` [kernel-hardening] " Ingo Molnar
2013-04-05 7:13 ` Ingo Molnar
2013-04-04 20:07 ` [kernel-hardening] [PATCH 3/3] x86: kernel base offset ASLR Kees Cook
2013-04-04 20:07 ` Kees Cook
2013-04-04 20:12 ` [kernel-hardening] " H. Peter Anvin
2013-04-04 20:12 ` H. Peter Anvin
2013-04-04 20:19 ` [kernel-hardening] " Julien Tinnes
2013-04-04 20:19 ` Julien Tinnes
2013-04-04 20:23 ` [kernel-hardening] " Julien Tinnes
2013-04-04 20:23 ` Julien Tinnes
2013-04-04 20:27 ` [kernel-hardening] " H. Peter Anvin
2013-04-04 20:27 ` H. Peter Anvin
2013-04-04 20:48 ` [kernel-hardening] " Julien Tinnes
2013-04-04 20:48 ` Julien Tinnes
2013-04-05 7:05 ` [kernel-hardening] " Ingo Molnar
2013-04-05 7:05 ` Ingo Molnar
2013-04-04 20:54 ` [kernel-hardening] " Kees Cook
2013-04-04 20:54 ` Kees Cook
2013-04-04 20:58 ` [kernel-hardening] " H. Peter Anvin
2013-04-04 20:58 ` H. Peter Anvin
2013-04-04 21:00 ` [kernel-hardening] " Kees Cook
2013-04-04 21:00 ` Kees Cook
2013-04-04 21:01 ` [kernel-hardening] " H. Peter Anvin
2013-04-04 21:01 ` H. Peter Anvin
2013-04-04 21:04 ` [kernel-hardening] " Eric Northup
2013-04-04 21:04 ` Eric Northup
2013-04-04 21:06 ` [kernel-hardening] " Kees Cook
2013-04-04 21:06 ` Kees Cook
2013-04-04 21:00 ` [kernel-hardening] " Julien Tinnes
2013-04-04 21:00 ` Julien Tinnes
2013-04-04 21:01 ` [kernel-hardening] " Eric Northup
2013-04-04 21:01 ` Eric Northup
2013-04-05 7:55 ` [kernel-hardening] " Ingo Molnar
2013-04-05 7:55 ` Ingo Molnar
2013-04-04 20:21 ` H. Peter Anvin [this message]
2013-04-04 20:21 ` H. Peter Anvin
2013-04-04 20:47 ` [kernel-hardening] " Eric Northup
2013-04-04 20:47 ` Eric Northup
2013-04-05 1:08 ` [kernel-hardening] " H. Peter Anvin
2013-04-05 1:08 ` H. Peter Anvin
2013-04-05 8:04 ` [kernel-hardening] " Ingo Molnar
2013-04-05 8:04 ` Ingo Molnar
2013-04-05 15:30 ` [kernel-hardening] " H. Peter Anvin
2013-04-05 15:30 ` H. Peter Anvin
2013-04-08 11:58 ` [kernel-hardening] " Ingo Molnar
2013-04-08 11:58 ` Ingo Molnar
2013-04-08 14:58 ` [kernel-hardening] " H. Peter Anvin
2013-04-08 14:58 ` H. Peter Anvin
2013-04-05 18:17 ` [kernel-hardening] " H. Peter Anvin
2013-04-05 18:17 ` H. Peter Anvin
2013-04-05 20:01 ` [kernel-hardening] " Yinghai Lu
2013-04-05 20:01 ` Yinghai Lu
2013-04-05 20:05 ` [kernel-hardening] " H. Peter Anvin
2013-04-05 20:05 ` H. Peter Anvin
2013-04-05 20:19 ` [kernel-hardening] " Yinghai Lu
2013-04-05 20:19 ` Yinghai Lu
2013-04-05 20:29 ` [kernel-hardening] " H. Peter Anvin
2013-04-05 20:29 ` H. Peter Anvin
2013-04-05 7:11 ` [kernel-hardening] " Ingo Molnar
2013-04-05 7:11 ` Ingo Molnar
2013-04-05 22:06 ` [kernel-hardening] " Julien Tinnes
2013-04-05 22:06 ` Julien Tinnes
2013-04-05 22:08 ` [kernel-hardening] " H. Peter Anvin
2013-04-05 22:08 ` H. Peter Anvin
2013-04-05 22:13 ` [kernel-hardening] " Julien Tinnes
2013-04-05 22:13 ` Julien Tinnes
2013-04-05 7:34 ` [kernel-hardening] " Ingo Molnar
2013-04-05 7:34 ` Ingo Molnar
2013-04-05 12:12 ` [kernel-hardening] " Jiri Kosina
2013-04-05 12:12 ` Jiri Kosina
2013-04-05 14:49 ` [kernel-hardening] " Borislav Petkov
2013-04-05 14:49 ` Borislav Petkov
2013-04-05 20:19 ` [kernel-hardening] " Julien Tinnes
2013-04-05 20:19 ` Julien Tinnes
2013-04-05 20:43 ` [kernel-hardening] " Borislav Petkov
2013-04-05 20:43 ` Borislav Petkov
2013-04-05 23:18 ` [kernel-hardening] " Kees Cook
2013-04-05 23:18 ` Kees Cook
2013-04-06 10:10 ` [kernel-hardening] " Borislav Petkov
2013-04-06 10:10 ` Borislav Petkov
2013-04-08 5:34 ` [kernel-hardening] " Hasinoliva MIARIMANJATO
2013-04-08 12:13 ` Ingo Molnar
2013-04-08 12:13 ` Ingo Molnar
2013-04-08 5:34 ` [kernel-hardening] [PATCH 0/3] kernel ASLR Hasinoliva MIARIMANJATO
2013-04-11 20:52 ` [kernel-hardening] " H. Peter Anvin
2013-04-11 20:52 ` H. Peter Anvin
2013-04-11 21:28 ` [kernel-hardening] " Kees Cook
2013-04-11 21:28 ` Kees Cook
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