Messages in this thread |  | | From | Matthew Garrett <> | Subject | Re: [PATCH] x86: Lock down MSR writing in secure boot | Date | Fri, 8 Feb 2013 19:27:09 +0000 |
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On Fri, 2013-02-08 at 11:21 -0800, Kees Cook wrote: > On Fri, Feb 8, 2013 at 11:17 AM, Matthew Garrett > <matthew.garrett@nebula.com> wrote: > > On Fri, 2013-02-08 at 11:12 -0800, Kees Cook wrote: > >> Writing to MSRs should not be allowed unless CAP_COMPROMISE_KERNEL is > >> set since it could lead to execution of arbitrary code in kernel mode. > > > > Willing to buy this, but do you have a description of one potential > > approach? We should probably also figure out what's writing to MSRs at > > the moment (anything other than energy_perf_bias?) and decide what the > > best thing to do there is. > > Yes, change the SYSENTER entry point to where-ever you like. There are > examples already written: > http://grsecurity.net/~spender/msr32.c
Cool. Yup, this sounds like a good plan.
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