Messages in this thread |  | | Date | Fri, 08 Feb 2013 17:22:20 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] x86: Lock down MSR writing in secure boot |
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On 02/08/2013 03:26 PM, Matthew Garrett wrote: > On Sat, 2013-02-09 at 00:06 +0100, Borislav Petkov wrote: >> On Fri, Feb 08, 2013 at 02:30:52PM -0800, H. Peter Anvin wrote: >>> Also, keep in mind that there is a very simple way to deny MSR access >>> completely, which is to not include the driver in your kernel (and not >>> allow module loading, but if you can load modules you can just load a >>> module to muck with whatever MSR you want.) >> >> I was contemplating that too. What is the use case of having >> msr.ko in a secure boot environment? Isn't that an all-no-tools, >> you-can't-do-sh*t-except-what-you're-explicitly-allowed-to environment which >> simply doesn't need to write MSRs in the first place? > > Well, sure, distributions could build every kernel twice. That seems a > little excessive, though. >
You don't have to build the kernel twice to exclude a loadable module.
-hpa
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