Re: [RFC PATCH 7/9] x86/sgx: Enforce noexec filesystem restriction for enclaves

From: Andy Lutomirski
Date: Tue Jun 04 2019 - 16:36:26 EST


On Tue, Jun 4, 2019 at 9:26 AM Jarkko Sakkinen
<jarkko.sakkinen@xxxxxxxxxxxxxxx> wrote:
>
> On Fri, May 31, 2019 at 04:31:57PM -0700, Sean Christopherson wrote:
> > Do not allow an enclave page to be mapped with PROT_EXEC if the source
> > page is backed by a file on a noexec file system.
> >
> > Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
>
> Why don't you just check in sgx_encl_add_page() that whether the path
> comes from noexec and deny if SECINFO contains X?
>

SECINFO seems almost entirely useless for this kind of thing because
of SGX2. I'm thinking that SECINFO should be completely ignored for
anything other than its required architectural purpose.