From: Matthew Garrett <matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org>
To: Greg KH <gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>
Cc: Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>,
"linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org"
<hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
Subject: Re: [PATCH V3 08/11] kexec: Disable at runtime if the kernel enforces module loading restrictions
Date: Sun, 8 Sep 2013 16:24:47 +0000 [thread overview]
Message-ID: <1378657487.2300.10.camel@x230> (raw)
In-Reply-To: <20130908161859.GA18946-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
On Sun, 2013-09-08 at 09:18 -0700, Greg KH wrote:
> I want both, but I don't need signed kexec support because I want to use
> kexec for a program that I "know" is correct because I validated the
> disk image it was on before I mounted it. We already have other ways to
> "verify" things without having to add individual verification of
> specific pieces.
The kernel has no way to know that your kexec payload is coming from a
verified image. It'll just as happily take something from an unverified
image. If you've ensured that there's no way an attacker can call
kexec_load() on an unverified image, then you don't need signed modules.
--
Matthew Garrett <matthew.garrett@nebula.com>
next prev parent reply other threads:[~2013-09-08 16:24 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-03 23:50 (unknown), Matthew Garrett
2013-09-03 23:50 ` [PATCH V3 01/11] Add secure_modules() call Matthew Garrett
[not found] ` <1378252218-18798-2-git-send-email-matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org>
2013-09-04 0:45 ` James Morris
2013-09-05 2:14 ` joeyli
2013-09-03 23:50 ` [PATCH V3 02/11] PCI: Lock down BAR access when module security is enabled Matthew Garrett
[not found] ` <1378252218-18798-3-git-send-email-matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org>
2013-09-04 0:45 ` James Morris
2013-09-04 16:57 ` David Woodhouse
[not found] ` <1378313861.4210.39.camel-W2I5cNIroUsVm/YvaOjsyQ@public.gmane.org>
2013-09-04 17:04 ` Matthew Garrett
2013-09-04 18:58 ` David Woodhouse
[not found] ` <1378321109.2627.9.camel-Fexsq3y4057IgHVZqg5X0TlWvGAXklZc@public.gmane.org>
2013-09-04 19:01 ` Matthew Garrett
2013-09-04 19:31 ` David Woodhouse
2013-09-03 23:50 ` [PATCH V3 03/11] x86: Lock down IO port " Matthew Garrett
2013-09-04 0:45 ` James Morris
[not found] ` <1378252218-18798-4-git-send-email-matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org>
2013-09-05 3:52 ` H. Peter Anvin
[not found] ` <5227FFE8.5050102-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
2013-09-05 3:58 ` Matthew Garrett
2013-09-05 15:36 ` H. Peter Anvin
2013-09-03 23:50 ` [PATCH V3 04/11] ACPI: Limit access to custom_method Matthew Garrett
[not found] ` <1378252218-18798-5-git-send-email-matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org>
2013-09-04 0:46 ` James Morris
2013-09-03 23:50 ` [PATCH V3 05/11] asus-wmi: Restrict debugfs interface when module loading is restricted Matthew Garrett
[not found] ` <1378252218-18798-6-git-send-email-matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org>
2013-09-04 0:46 ` James Morris
2013-09-03 23:50 ` [PATCH V3 06/11] Restrict /dev/mem and /dev/kmem " Matthew Garrett
[not found] ` <1378252218-18798-7-git-send-email-matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org>
2013-09-04 0:47 ` James Morris
2013-09-03 23:50 ` [PATCH V3 08/11] kexec: Disable at runtime if the kernel enforces module loading restrictions Matthew Garrett
[not found] ` <1378252218-18798-9-git-send-email-matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org>
2013-09-04 0:48 ` James Morris
2013-09-04 20:09 ` jerry.hoemann-VXdhtT5mjnY
[not found] ` <20130904200959.GE8540-dMAi7lA+vBPDUbYHzcRnttBPR1lH4CV8@public.gmane.org>
2013-09-04 20:12 ` Matthew Garrett
2013-09-04 20:14 ` Josh Boyer
2013-09-08 6:40 ` Greg KH
[not found] ` <20130908064027.GA3587-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2013-09-08 6:44 ` Matthew Garrett
2013-09-08 7:24 ` Greg KH
[not found] ` <20130908072408.GA5092-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2013-09-08 14:40 ` Matthew Garrett
2013-09-08 15:51 ` Kees Cook
[not found] ` <CAGXu5jLwCt6RtQC+kxcUC69tMydx8DO2QWDv3jK6_mOyT_iNbA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-09-08 16:18 ` Greg KH
[not found] ` <20130908161859.GA18946-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2013-09-08 16:24 ` Matthew Garrett [this message]
2013-09-08 16:39 ` Greg KH
[not found] ` <20130908163926.GA19665-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2013-09-08 16:59 ` Matthew Garrett
2013-09-08 17:22 ` Greg KH
[not found] ` <20130908172249.GB20959-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2013-09-08 17:25 ` Matthew Garrett
2013-09-08 17:11 ` James Bottomley
[not found] ` <1378660284.2429.11.camel-sFMDBYUN5F8GjUHQrlYNx2Wm91YjaHnnhRte9Li2A+AAvxtiuMwx3w@public.gmane.org>
2013-09-08 17:15 ` Matthew Garrett
2013-09-08 17:22 ` James Bottomley
[not found] ` <1378660975.2429.14.camel-sFMDBYUN5F8GjUHQrlYNx2Wm91YjaHnnhRte9Li2A+AAvxtiuMwx3w@public.gmane.org>
2013-09-08 17:27 ` Matthew Garrett
2013-09-08 17:32 ` James Bottomley
[not found] ` <1378661576.2429.16.camel-sFMDBYUN5F8GjUHQrlYNx2Wm91YjaHnnhRte9Li2A+AAvxtiuMwx3w@public.gmane.org>
2013-09-08 17:38 ` Matthew Garrett
2013-09-03 23:50 ` [PATCH V3 09/11] uswsusp: Disable when module loading is restricted Matthew Garrett
[not found] ` <1378252218-18798-10-git-send-email-matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org>
2013-09-04 0:48 ` James Morris
2013-09-05 3:20 ` joeyli
2013-09-03 23:50 ` [PATCH V3 10/11] x86: Restrict MSR access " Matthew Garrett
[not found] ` <1378252218-18798-11-git-send-email-matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org>
2013-09-04 0:49 ` James Morris
[not found] ` <1378252218-18798-1-git-send-email-matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org>
2013-09-03 23:50 ` [PATCH V3 07/11] acpi: Ignore acpi_rsdp kernel parameter " Matthew Garrett
2013-09-03 23:50 ` [PATCH V3 11/11] Add option to automatically enforce module signatures when in Secure Boot mode Matthew Garrett
[not found] ` <1378252218-18798-12-git-send-email-matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org>
2013-09-04 1:42 ` James Morris
2013-09-04 1:42 ` Matthew Garrett
2013-09-05 8:24 ` joeyli
2013-09-05 10:16 ` Matt Fleming
[not found] ` <20130905101649.GL28598-HNK1S37rvNbeXh+fF434Mdi2O/JbrIOy@public.gmane.org>
2013-09-05 12:54 ` Matthew Garrett
2013-09-05 3:13 ` joeyli
2013-09-04 15:53 ` Kees Cook
[not found] ` <CAGXu5jLCTU1MG4fYDzpT=TAP9DRAUuRuhZNB+edJsOzN4iXbDw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-09-04 16:05 ` Re: Josh Boyer
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