From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Sakkinen Subject: Re: [PATCH v17 18/23] platform/x86: Intel SGX driver Date: Mon, 26 Nov 2018 14:16:49 -0800 Message-ID: <20181126221649.GE868@linux.intel.com> References: <20181120120442.GA22172@linux.intel.com> <20181122111253.GA31150@wind.enjellic.com> <20181124172114.GB32210@linux.intel.com> <20181125145329.GA5777@linux.intel.com> <0669C300-02CB-4EA6-BF88-5C4B4DDAD4C7@amacapital.net> <20181125185524.GA23224@wind.enjellic.com> <94154ECB-3EF7-4A37-9057-0B84DBCE650E@amacapital.net> <20181126110038.GA27609@wind.enjellic.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20181126110038.GA27609@wind.enjellic.com> Sender: linux-kernel-owner@vger.kernel.org To: "Dr. Greg" Cc: Andy Lutomirski , Andy Lutomirski , X86 ML , Platform Driver , linux-sgx@vger.kernel.org, Dave Hansen , "Christopherson, Sean J" , nhorman@redhat.com, npmccallum@redhat.com, "Ayoun, Serge" , shay.katz-zamir@intel.com, haitao.huang@linux.intel.com, Andy Shevchenko , Thomas Gleixner , "Svahn, Kai" , mark.shanahan@intel.com, Suresh Siddha , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Darren Hart , Andy Shevchenko List-Id: platform-driver-x86.vger.kernel.org On Mon, Nov 26, 2018 at 05:00:39AM -0600, Dr. Greg wrote: > We will be interested in your comments as to why the proposal is > insufficient in the real world of FLC. > > I believe the proposed architecture can be defended as being effective > in the real world, as it allows the root user to use cryptographic > protections of access to the PROVISION bit and to enclave execution in > general. On FLC that is the strongest guarantee that can be > delivered. > > When we speak of 'unauthorized' users I believe we are speaking in the > parlance of discretionary access controls which has a much wider TCB > scope then the cryptographic model we are proposing. The model we > propose allows the platform owner (root) to effectively implement the > same level of security over the PROVISION bit that current locked > platforms have, in a free and open fashion of course. > > We can certainly attempt to explain our position further. I think kernel controlled provision would in all cases lower the mitigations of thread scenarios (at least what you've presented so far) assuming that a compromissed kernel could be detected fairly quickly, wouldn't it? Even without SGX, having a compromissed kernel, you can anyhow stealth your malware in many ways. /Jarkko