From: "H. Peter Anvin" <hpa@zytor.com>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: Matthew Garrett <matthew.garrett@nebula.com>,
Rik van Riel <riel@redhat.com>, Kees Cook <keescook@chromium.org>,
"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
kexec@lists.infradead.org, LKML <linux-kernel@vger.kernel.org>,
Eric Biederman <ebiederm@xmission.com>,
Rob Landley <rob@landley.net>,
Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@kernel.org>, Mel Gorman <mgorman@suse.de>
Subject: Re: [PATCH v2] kexec: add sysctl to disable kexec
Date: Tue, 10 Dec 2013 10:54:00 -0800 [thread overview]
Message-ID: <52A76348.5080803@zytor.com> (raw)
In-Reply-To: <20131210183352.GD13909@redhat.com>
On 12/10/2013 10:33 AM, Vivek Goyal wrote:
> On Tue, Dec 10, 2013 at 08:32:38AM -0800, H. Peter Anvin wrote:
>> Of course it isn't.
>
> I am not sure what are you trying to say. This is too brief.
>
> Thanks
> Vivek
>
Of course it is not sufficient. Once you can get arbitrary code into
kernel space (CPL 0) you can do anything, and "disabling jump back" is
just a speed bump.
-hpa
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WARNING: multiple messages have this Message-ID (diff)
From: "H. Peter Anvin" <hpa@zytor.com>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: Kees Cook <keescook@chromium.org>,
LKML <linux-kernel@vger.kernel.org>,
Rik van Riel <riel@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Matthew Garrett <matthew.garrett@nebula.com>,
Rob Landley <rob@landley.net>,
Eric Biederman <ebiederm@xmission.com>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Mel Gorman <mgorman@suse.de>,
"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
kexec@lists.infradead.org
Subject: Re: [PATCH v2] kexec: add sysctl to disable kexec
Date: Tue, 10 Dec 2013 10:54:00 -0800 [thread overview]
Message-ID: <52A76348.5080803@zytor.com> (raw)
In-Reply-To: <20131210183352.GD13909@redhat.com>
On 12/10/2013 10:33 AM, Vivek Goyal wrote:
> On Tue, Dec 10, 2013 at 08:32:38AM -0800, H. Peter Anvin wrote:
>> Of course it isn't.
>
> I am not sure what are you trying to say. This is too brief.
>
> Thanks
> Vivek
>
Of course it is not sufficient. Once you can get arbitrary code into
kernel space (CPL 0) you can do anything, and "disabling jump back" is
just a speed bump.
-hpa
next prev parent reply other threads:[~2013-12-10 18:54 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-10 0:16 [PATCH v2] kexec: add sysctl to disable kexec Kees Cook
2013-12-10 0:16 ` Kees Cook
2013-12-10 0:34 ` H. Peter Anvin
2013-12-10 0:34 ` H. Peter Anvin
2013-12-10 1:06 ` Kees Cook
2013-12-10 1:06 ` Kees Cook
2013-12-10 14:35 ` Vivek Goyal
2013-12-10 14:35 ` Vivek Goyal
2013-12-10 14:38 ` Vivek Goyal
2013-12-10 14:38 ` Vivek Goyal
2013-12-10 16:32 ` H. Peter Anvin
2013-12-10 16:32 ` H. Peter Anvin
2013-12-10 18:33 ` Vivek Goyal
2013-12-10 18:33 ` Vivek Goyal
2013-12-10 18:54 ` H. Peter Anvin [this message]
2013-12-10 18:54 ` H. Peter Anvin
2013-12-10 19:14 ` Vivek Goyal
2013-12-10 19:14 ` Vivek Goyal
2013-12-10 19:33 ` Kees Cook
2013-12-10 19:33 ` Kees Cook
2013-12-11 17:52 ` Eric W. Biederman
2013-12-11 17:52 ` Eric W. Biederman
2013-12-11 21:13 ` Kees Cook
2013-12-11 21:13 ` Kees Cook
2013-12-11 23:15 ` Eric W. Biederman
2013-12-11 23:15 ` Eric W. Biederman
2013-12-11 23:22 ` Kees Cook
2013-12-11 23:22 ` Kees Cook
2013-12-12 1:14 ` Eric W. Biederman
2013-12-12 1:14 ` Eric W. Biederman
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