From: Mimi Zohar <zohar@linux.vnet.ibm.com>
To: J Freyensee <why2jjj.linux@gmail.com>, linux-integrity@vger.kernel.org
Cc: linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org, David Howells <dhowells@redhat.com>,
"Luis R . Rodriguez" <mcgrof@kernel.org>,
Eric Biederman <ebiederm@xmission.com>,
kexec@lists.infradead.org, Andres Rodriguez <andresx7@gmail.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH v5 3/8] ima: based on policy require signed kexec kernel images
Date: Tue, 03 Jul 2018 09:07:39 -0400 [thread overview]
Message-ID: <1530623259.3452.28.camel@linux.vnet.ibm.com> (raw)
In-Reply-To: <840dae63-5a90-1327-437e-1ed92e165754@gmail.com>
On Mon, 2018-07-02 at 11:31 -0700, J Freyensee wrote:
>
> On 7/2/18 7:37 AM, Mimi Zohar wrote:
> > The original kexec_load syscall can not verify file signatures, nor can
> > the kexec image be measured. Based on policy, deny the kexec_load
> > syscall.
>
>
> Curiosity question: I thought kexec_load() syscall was used to load a
> crashdump?
kexec is used to collect the memory used to analyze the crash dump.
> If this is true, how would this work if kexec_load() is
> being denied? I don't think I'd want to be hindered in cases where I'm
> trying to diagnose a crash.
For trusted & secure boot, we need a full measurement list and
signature chain of trust rooted in HW. Permitting kexec_load would
break these chains of trust.
Permitting/denying kexec_load is based on a runtime IMA policy. Patch
6/8 "ima: add build time policy", in this patch set, introduces the
concept of a build time policy. With these patches, you could
configure your kernel and/or load an IMA policy permitting kexec_load.
Mimi
next prev parent reply other threads:[~2018-07-03 13:08 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-02 14:37 [PATCH v5 0/8] kexec/firmware: support system wide policy requiring signatures Mimi Zohar
2018-07-02 14:37 ` [PATCH v5 1/8] security: define new LSM hook named security_kernel_load_data Mimi Zohar
2018-07-02 18:45 ` J Freyensee
2018-07-03 12:35 ` Mimi Zohar
2018-07-02 14:37 ` [PATCH v5 2/8] kexec: add call to LSM hook in original kexec_load syscall Mimi Zohar
2018-07-10 20:26 ` Mimi Zohar
2018-07-02 14:37 ` [PATCH v5 3/8] ima: based on policy require signed kexec kernel images Mimi Zohar
2018-07-02 18:31 ` J Freyensee
2018-07-03 13:07 ` Mimi Zohar [this message]
2018-07-02 14:37 ` [PATCH v5 4/8] firmware: add call to LSM hook before firmware sysfs fallback Mimi Zohar
2018-07-03 12:04 ` kbuild test robot
2018-07-02 14:38 ` [PATCH v5 5/8] ima: based on policy require signed firmware (sysfs fallback) Mimi Zohar
2018-07-02 14:38 ` [PATCH v5 6/8] ima: add build time policy Mimi Zohar
2018-07-02 14:38 ` [PATCH v5 7/8] ima: based on policy warn about loading firmware (pre-allocated buffer) Mimi Zohar
2018-07-02 15:30 ` Ard Biesheuvel
2018-07-09 19:41 ` Mimi Zohar
2018-07-10 6:51 ` Ard Biesheuvel
2018-07-10 6:56 ` Ard Biesheuvel
2018-07-10 18:47 ` Mimi Zohar
2018-07-10 19:19 ` Bjorn Andersson
2018-07-11 6:24 ` Ard Biesheuvel
2018-07-12 20:03 ` Mimi Zohar
2018-07-12 20:37 ` Bjorn Andersson
2018-07-02 14:38 ` [PATCH v5 8/8] module: replace the existing LSM hook in init_module Mimi Zohar
2018-07-03 9:35 ` kbuild test robot
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