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
Thread-Topic: [PATCH V3 08/11] kexec: Disable at runtime if the kernel
 enforces module loading restrictions
Thread-Index: AQHOqQBlTgRtcELUZ0K5HxHj5bQ8FZm7apqAgACzh7qAAAFEAA==
Date: Sun, 8 Sep 2013 17:27:32 +0000
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> 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. 

-- 
Matthew Garrett <matthew.garrett@nebula.com>
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