Re: [RESEND PATCH 3/3] x86/sgx: Add xa_store_range() return value check in sgx_setup_epc_section()

[Huang, Kai]

On Wed, 2022-10-05 at 01:21 +0300, Jarkko Sakkinen wrote:
> On Tue, Oct 04, 2022 at 11:04:29AM +1300, Kai Huang wrote:
> > In sgx_setup_epc_section(), xa_store_range() is called to store EPC
> > pages' owner section to an Xarray using physical addresses of those EPC
> > pages as index.  Currently, the return value of xa_store_range() is not
> > checked, but actually it can fail (i.e. due to -ENOMEM).
> > 
> > Not checking the return value of xa_store_range() would result in the
> > EPC section being used by SGX driver (and KVM SGX guests), but part or
> > all of its EPC pages not being handled by the memory failure handling of
> > EPC page.  Such inconsistency should be avoided, even at the cost that
> > this section won't be used by the kernel.
> > 
> > Add the missing check of the return value of xa_store_range(), and when
> > it fails, clean up and fail to initialize the EPC section.
> > 
> > Fixes: 40e0e7843e23 ("x86/sgx: Add infrastructure to identify SGX EPC pages")
> > Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx>
> 
> Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> 
> This needs:
> 
> Cc: stable@xxxxxxxxxxxxxxx # v5.17+
> 
> Dave, can you pick this independently of rest of the patch set
> (unless ofc you have change suggestions)?
> 
> BR, Jarkko

Thanks Jarkko.  I will add the "Cc stable" part if I need to send out a new
version.
 
-- 
Thanks,
-Kai