Re: [REGRESSION][BISECTED] erroneous buffer overflow detected in bch2_xattr_validate

From: Kees Cook
Date: Thu Oct 03 2024 - 17:23:32 EST


On Wed, Oct 02, 2024 at 11:18:57AM +0200, Thorsten Blum wrote:
> On 28. Sep 2024, at 22:34, Kees Cook <kees@xxxxxxxxxx> wrote:
> > [...]
> >
> > Sorry, I've been out of commission with covid. Globally disabling this
> > macro for clang is not the right solution (way too big a hammer).
> >
> > Until Bill has a fix, we can revert commit
> > 86e92eeeb23741a072fe7532db663250ff2e726a, as the problem is limited to
> > certain situations where 'counted_by' is in use.
>
> I already encountered two other related __counted_by() issues [1][2]
> that are now being reverted. Would it be an option to disable it
> globally, but only for Clang < v19 (where it looks like it'll be fixed)?

Yeah, once we have a solid fix (so we have a known Clang version to
target), I'll want counted_by disabled in versions prior to that.

--
Kees Cook