On Mon, Oct 05, 2020 at 03:46:26PM -0700, Sean Christopherson wrote: > On Mon, Oct 05, 2020 at 02:38:40PM +0300, Jarkko Sakkinen wrote: > > On Sun, Oct 04, 2020 at 11:00:28PM -0500, Haitao Huang wrote: > > > On Sun, 04 Oct 2020 21:08:19 -0500, Jarkko Sakkinen > > > <jarkko.sakkinen@xxxxxxxxxxxxxxx> wrote: > > > > > > > Remove from sgx_validate_secs(): > > > > > > > > if (secs->miscselect & sgx_misc_reserved_mask || > > > > secs->attributes & sgx_attributes_reserved_mask || > > > > secs->xfrm & sgx_xfrm_reserved_mask) > > > > return -EINVAL; > > > > > > > > SECS can surpass the platform limits because it's the SIGSTRUCT that > > > > defines the limits that are used at run-time. > > > > > > > > What SECS does is that it defines the overall limits that must apply for > > > > any platform, i.e. SECS limits and platform limits are orthogonal. They > > > > are not dependent. > > > > > > > > Cc: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > > > > Cc: Jethro Beekman <jethro@xxxxxxxxxxxx> > > > > Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > > > > Suggested-by: Haitao Huang <haitao.huang@xxxxxxxxxxxxxxx> > > > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> > > > > --- > > > > arch/x86/kernel/cpu/sgx/ioctl.c | 5 ----- > > > > 1 file changed, 5 deletions(-) > > > > > > > > diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c > > > > b/arch/x86/kernel/cpu/sgx/ioctl.c > > > > index 6b3cc8483008..008752cb54f0 100644 > > > > --- a/arch/x86/kernel/cpu/sgx/ioctl.c > > > > +++ b/arch/x86/kernel/cpu/sgx/ioctl.c > > > > @@ -86,11 +86,6 @@ static int sgx_validate_secs(const struct sgx_secs > > > > *secs) > > > > if (secs->base & (secs->size - 1)) > > > > return -EINVAL; > > > > - if (secs->miscselect & sgx_misc_reserved_mask || > > > > - secs->attributes & sgx_attributes_reserved_mask || > > > > - secs->xfrm & sgx_xfrm_reserved_mask) > > > > - return -EINVAL; > > > > - > > > > if (secs->size > max_size) > > > > return -EINVAL; > > > > > > > > > > Looks good to me. > > > Thanks > > > Haitao > > > > Thanks, I'll merge it then. > > You can't remove this wholesale, the kernel should still disallow access to > features that are unknown to the kernel and/or are explicitly disallowed by > the kernel. E.g. see SGX_ATTR_RESERVED_MASK and SGX_MISC_RESERVED_MASK. > > Dropping sgx_xfrm_reserved_mask is ok because the CPU explicitly checks that > XFRM is a strict subset of the current XCR0, though that makes me wonder what > it does with XSS... If possible send a patch so I can get a changelog reference. Only thing you need to put as long description is permlink to my response in this thread. Thank you. /Jarkko
