Re: [PATCH 1/1] ACPI: fix acpi table use after free

[David Hildenbrand]

> > > Memory gets allocated and used in a different order, which seems to have
> > > exposed (yet another) latent BUG.
> >
> > Well, you can call it that, or you can say that things worked under
> > certain assumptions regarding the memory allocation order which are
> > not met any more.
> >
> > > The same could be reproduced via zone shuffling with a little luck.
> >
> > But nobody does that in practice.

Dan will most certainly object. And I don't know what makes you speak in 
absolute words here.

> > This would be relatively straightforward to address if ACPICA was not
> > involved in it, but unfortunately that's not the case.
> >
> > Changing this part of ACPICA is risky, because such changes may affect
> > other OSes using it, so that requires some serious consideration.
> > Alternatively, the previous memory allocation order in Linux could be
> > restored.
>
> Of course, long-term this needs to be addressed in the ACPI
> initialization code, because it clearly is not robust enough, but in
> the meantime there's practical breakage observable in the field, so
> what can be done about that?

*joke* enable zone shuffling.

No seriously, fix the latent BUG. What again is problematic about 
excluding these pages from the page allcoator, for example, via 
memblock_reserve()?

@Mike?

--
Thanks,

David / dhildenb