Re: SGX vs LSM (Re: [PATCH v20 00/28] Intel SGX1 support)
From: Andy Lutomirski <luto@kernel.org>
Date: 2019-05-24 19:30:59
Also in:
lkml, selinux
On Fri, May 24, 2019 at 12:13 PM Sean Christopherson [off-list ref] wrote:
On Fri, May 24, 2019 at 11:34:32AM -0700, Xing, Cedric wrote:quoted
quoted
From: linux-sgx-owner@vger.kernel.org [mailto:linux-sgx- owner@vger.kernel.org] On Behalf Of Sean Christopherson Sent: Friday, May 24, 2019 10:55 AM
I don't see a fundamental difference between having RWX in an enclave and RWX in normal memory, either way the process can execute arbitrary code, i.e. PROCESS__EXECMEM is appropriate. Yes, an enclave will #UD on certain instructions, but that's easily sidestepped by having a trampoline in the host (marked RX) and piping arbitrary code into the enclave. Or using EEXIT to do a bit of ROP.
There's a difference, albeit a somewhat weak one, if sigstructs are whitelisted. FILE__EXECMOD on either /dev/sgx/enclave or on the sigstruct is not an entirely crazy way to express this.