Re: [PATCH v2] efi_64: Fix a missing-check bug in arch/x86/platform/efi/efi_64.c

From: Gen Zhang
Date: Sat May 25 2019 - 05:44:24 EST


On Sat, May 25, 2019 at 11:18:36AM +0200, Ard Biesheuvel wrote:
> On Sat, 25 May 2019 at 04:36, Gen Zhang <blackgod016574@xxxxxxxxx> wrote:
> >
> > On Fri, May 24, 2019 at 06:07:10PM +0200, Ard Biesheuvel wrote:
> > > Apologies for only spotting this now, but I seem to have given some bad advice.
> > >
> > > efi_call_phys_prolog() in efi_64.c will also return NULL if
> > > (!efi_enabled(EFI_OLD_MEMMAP)), but this is not an error condition. So
> > > that occurrence has to be updated: please return efi_mm.pgd instead.
> > Thanks for your reply, Ard. You mean that we should return efi_mm.pgd
> > when allcoation fails? And we should delete return EFI_ABORTED on the
> > caller site, right? In that case, how should we handle the NULL pointer
> > returned by condition if(!efi_enabled(EFI_OLD_MEMMAP)) on the caller
> > site?
> >
>
> No, the other way around. I have already updated the patch, so don't
> worry about it.
>
> https://git.kernel.org/pub/scm/linux/kernel/git/efi/efi.git/commit/?h=urgent&id=d2dc2bc7b60b936b95da4b04c2912c02974c3e9f
Thanks for your reply and update, Ard! That's really nice of you.

Thanks
Gen