From: Vivek Goyal <vgoyal@redhat.com>
To: "H. Peter Anvin" <hpa@zytor.com>, Kees Cook <keescook@chromium.org>
Cc: 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 14:14:09 -0500 [thread overview]
Message-ID: <20131210191409.GE13909@redhat.com> (raw)
In-Reply-To: <52A76348.5080803@zytor.com>
On Tue, Dec 10, 2013 at 10:54:00AM -0800, H. Peter Anvin wrote:
> 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.
Agreed that disabling jump back is only a speed bump.
Kees, so how would be use this knob?
- If I put it in some init script, then root will permission to modify
and remove it.
- Can one specify sysctl parameters on command line? If yes, then one
can disable this using kernel command line and in that case kdump will
be disabled too.
Thanks
Vivek
next prev parent reply other threads:[~2013-12-10 19:15 UTC|newest]
Thread overview: 15+ 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 0:34 ` H. Peter Anvin
2013-12-10 1:06 ` Kees Cook
2013-12-10 14:35 ` Vivek Goyal
2013-12-10 14:38 ` Vivek Goyal
2013-12-10 16:32 ` H. Peter Anvin
2013-12-10 18:33 ` Vivek Goyal
2013-12-10 18:54 ` H. Peter Anvin
2013-12-10 19:14 ` Vivek Goyal [this message]
2013-12-10 19:33 ` Kees Cook
2013-12-11 17:52 ` Eric W. Biederman
2013-12-11 21:13 ` Kees Cook
2013-12-11 23:15 ` Eric W. Biederman
2013-12-11 23:22 ` Kees Cook
2013-12-12 1:14 ` Eric W. Biederman
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