Re: [PATCH] x86: Lock down MSR writing in secure boot

[Matthew Garrett]

On Wed, 2013-02-13 at 09:51 -0800, Casey Schaufler wrote:
> On 2/13/2013 9:26 AM, Matthew Garrett wrote:
> > Admit that CAP_SYS_RAWIO is fucked up beyond rescue. Add a new
> > capability with well-defined semantics.
> 
> You can't add a new capability where there is an existing capability
> that can be remotely argued to be appropriate.

CAP_SYS_RAWIO can't be argued to be appropriate. It covers a range of
functionality that doesn't permit the running kernel to be modified and
which is required to provide a functional Linux system. Using it would
require redefining its existing usage, which would break existing
userspace.

-- 
Matthew Garrett | mjg59@xxxxxxxxxxxxx
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