From: Matthew Garrett <matthew.garrett@nebula.com>
To: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Kees Cook <keescook@chromium.org>,
Greg KH <gregkh@linuxfoundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-efi@vger.kernel.org" <linux-efi@vger.kernel.org>,
"hpa@zytor.com" <hpa@zytor.com>
Subject: Re: [PATCH V3 08/11] kexec: Disable at runtime if the kernel enforces module loading restrictions
Date: Sun, 8 Sep 2013 17:38:13 +0000 [thread overview]
Message-ID: <1378661893.2300.28.camel@x230> (raw)
In-Reply-To: <1378661576.2429.16.camel@dabdike.int.hansenpartnership.com>
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On Sun, 2013-09-08 at 10:32 -0700, James Bottomley wrote:
> On Sun, 2013-09-08 at 17:27 +0000, Matthew Garrett wrote:
> > > It's an argument that CAP_SYS_BOOT is too powerful yes, but if you
> > > recall, I said I keep that one. In the rather lame analogy, what I do
> > > by giving away CAP_SYS_MODULE and enforcing module signing while keeping
> > > CAP_SYS_BOOT is allow people into my conservatory to play with the
> > > plants but not into my house to steal the silver ... saying CAP_SYS_BOOT
> > > is too powerful doesn't affect that use case because I haven't given
> > > away CAP_SYS_BOOT.
> >
> > Ok, sorry, I had your meaning inverted. Yes, permitting the loading of
> > signed modules while preventing the use of kexec is a completely
> > reasonable configuration - so reasonable that it's what this patch
> > causes the kernel to do automatically.
>
> Well, no, it doesn't because with this patch, *I* can't use kexec ...
> you've just locked me out of my own house.
Hm. Ok, that's a more compelling argument than Greg's. Let me think
about whether there's a convenient way of supporting this.
--
Matthew Garrett <matthew.garrett@nebula.com>
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next prev parent reply other threads:[~2013-09-08 17:38 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-03 23:50 Matthew Garrett
2013-09-03 23:50 ` [PATCH V3 01/11] Add secure_modules() call Matthew Garrett
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
2013-09-04 0:45 ` James Morris
2013-09-04 16:57 ` David Woodhouse
2013-09-04 17:04 ` Matthew Garrett
2013-09-04 18:58 ` David Woodhouse
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
2013-09-05 3:52 ` H. Peter Anvin
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
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
2013-09-04 0:46 ` James Morris
2013-09-03 23:50 ` [PATCH V3 06/11] Restrict /dev/mem and /dev/kmem " Matthew Garrett
2013-09-04 0:47 ` James Morris
2013-09-03 23:50 ` [PATCH V3 07/11] acpi: Ignore acpi_rsdp kernel parameter " Matthew Garrett
2013-09-03 23:50 ` [PATCH V3 08/11] kexec: Disable at runtime if the kernel enforces module loading restrictions Matthew Garrett
2013-09-04 0:48 ` James Morris
2013-09-04 20:09 ` jerry.hoemann
2013-09-04 20:12 ` Matthew Garrett
2013-09-04 20:14 ` Josh Boyer
2013-09-08 6:40 ` Greg KH
2013-09-08 6:44 ` Matthew Garrett
2013-09-08 7:24 ` Greg KH
2013-09-08 14:40 ` Matthew Garrett
2013-09-08 15:51 ` Kees Cook
2013-09-08 16:18 ` Greg KH
2013-09-08 16:24 ` Matthew Garrett
2013-09-08 16:39 ` Greg KH
2013-09-08 16:59 ` Matthew Garrett
2013-09-08 17:22 ` Greg KH
2013-09-08 17:25 ` Matthew Garrett
2013-09-08 17:11 ` James Bottomley
2013-09-08 17:15 ` Matthew Garrett
2013-09-08 17:22 ` James Bottomley
2013-09-08 17:27 ` Matthew Garrett
2013-09-08 17:32 ` James Bottomley
2013-09-08 17:38 ` Matthew Garrett [this message]
2013-09-03 23:50 ` [PATCH V3 09/11] uswsusp: Disable when module loading is restricted Matthew Garrett
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
2013-09-04 0:49 ` James Morris
2013-09-03 23:50 ` [PATCH V3 11/11] Add option to automatically enforce module signatures when in Secure Boot mode Matthew Garrett
2013-09-04 1:42 ` James Morris
2013-09-04 1:42 ` Matthew Garrett
2013-09-05 3:13 ` joeyli
2013-09-05 8:24 ` joeyli
2013-09-05 10:16 ` Matt Fleming
2013-09-05 12:54 ` Matthew Garrett
2013-09-04 15:53 ` Kees Cook
2013-09-04 16:05 ` Re: Josh Boyer
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