Messages in this thread | | | Date | Fri, 27 Oct 2017 12:02:19 -0700 | From | Ricardo Neri <> | Subject | Re: [PATCH v9 02/29] x86/boot: Relocate definition of the initial state of CR0 |
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On Thu, Oct 26, 2017 at 02:55:13PM +0200, Borislav Petkov wrote: > On Thu, Oct 26, 2017 at 02:02:02AM -0700, Andy Lutomirski wrote: > > I'm assuming that UMIP_REPORTED_CR0 will never change. If CR0 gets a > > new field that we set some day, then I assume that CR0_STATE would add > > that bit but UMIP_REPORTED_CR0 would not. > > Yeah, let's do that when it is actually needed.
Thanks Andy! I reasoned that for UMIP could report CR0_STATE a value that is already revealed in the source code. Thus, if CR0 ever changes at run time, an attacker could only see what is set programmatically.
BR,
Ricardo
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