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From: Kees Cook <keescook@chromium.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: "kernel-hardening@lists.openwall.com" 
	<kernel-hardening@lists.openwall.com>,
	Ingo Molnar <mingo@redhat.com>,
	LKML <linux-kernel@vger.kernel.org>,
	"x86@kernel.org" <x86@kernel.org>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	Jeremy Fitzhardinge <jeremy@goop.org>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	Alex Shi <alex.shi@intel.com>,
	Borislav Petkov <borislav.petkov@amd.com>,
	Alexander Duyck <alexander.h.duyck@intel.com>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
	"virtualization@lists.linux-foundation.org" 
	<virtualization@lists.linux-foundation.org>,
	Dan Rosenberg <drosenberg@vsecurity.com>,
	Julien Tinnes <jln@google.com>, Will Drewry <wad@chromium.org>,
	Eric Northup <digitaleric@google.com>
Subject: Re: [kernel-hardening] Re: [PATCH] x86: make IDT read-only
Date: Tue, 9 Apr 2013 11:53:02 -0700	[thread overview]
Message-ID: <CAGXu5j+_sSVsB-D+zYyzBkj0HKzyVfJOBRAxMRmge2t=sSrTAg@mail.gmail.com> (raw)
In-Reply-To: <51646302.2030608@zytor.com>

On Tue, Apr 9, 2013 at 11:50 AM, H. Peter Anvin <hpa@zytor.com> wrote:
> On 04/09/2013 11:46 AM, Kees Cook wrote:
>>
>> Ah-ha! Yes, I see now when comparing the debug/kernel_page_tables
>> reports. It's just the High Kernel Mapping that we care about.
>> Addresses outside that range are less of a leak. Excellent, then GDT
>> may not be a problem. Whew.
>>
>
> It does beg the question if we need to randomize kmalloc... which could
> have issues by itself.

Agreed, but this should be a separate issue. As is the fact that GDT
is writable and a discoverable target.

-Kees

--
Kees Cook
Chrome OS Security

  reply	other threads:[~2013-04-09 18:53 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-08 22:43 [PATCH] x86: make IDT read-only Kees Cook
2013-04-08 22:47 ` H. Peter Anvin
2013-04-08 22:55   ` Kees Cook
2013-04-08 22:48 ` H. Peter Anvin
2013-04-09  9:23   ` Thomas Gleixner
2013-04-09 18:22     ` [kernel-hardening] " Kees Cook
2013-04-09 18:26       ` H. Peter Anvin
2013-04-09 18:31         ` Kees Cook
2013-04-09 18:39           ` H. Peter Anvin
2013-04-09 18:46             ` Kees Cook
2013-04-09 18:50               ` H. Peter Anvin
2013-04-09 18:53                 ` Kees Cook [this message]
2013-04-09 18:54               ` Eric Northup
2013-04-09 18:59                 ` H. Peter Anvin
2013-04-10  0:43                 ` Readonly GDT H. Peter Anvin
2013-04-10  0:53                   ` Steven Rostedt
2013-04-10  0:58                     ` H. Peter Anvin
2013-04-10  9:42                   ` [Xen-devel] " Jan Beulich
2013-04-10 14:16                     ` H. Peter Anvin
2013-04-10 18:28                     ` H. Peter Anvin
2013-04-10  9:41               ` [kernel-hardening] Re: [PATCH] x86: make IDT read-only Ingo Molnar
2013-04-10  0:03       ` H. Peter Anvin
2013-04-10  9:52         ` Ingo Molnar
2013-04-09  9:45   ` Eric W. Biederman
2013-04-10  9:57     ` Ingo Molnar
2013-04-10 10:40       ` Eric W. Biederman
2013-04-10 16:31         ` Eric Northup
2013-04-10 16:48           ` H. Peter Anvin
2013-04-08 22:56 ` Maciej W. Rozycki
2013-04-08 23:00   ` Kees Cook
2013-04-08 23:05   ` Kees Cook
2013-04-08 23:42     ` Maciej W. Rozycki

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