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

[Jarkko Sakkinen]

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