Re: [PATCH 1/2] bpf: deduce_bounds_64_from_32 tightening with circular range logic

Eduard Zingerman
2026-04-14T18:32:25Z

On Tue, 2026-04-14 at 13:25 -0300, Helen Koike wrote:
> Hi Shung-Hsi Yu,
>
>
> Thanks for your reply,
>
> On 4/14/26 5:26 AM, Shung-Hsi Yu wrote:
> > Hi Helen,
> >
> > On Fri, Apr 10, 2026 at 09:40:27AM -0300, Helen Koike wrote:
> > ...
> > > This is a follow-up from discussion:
> > > https://lore.kernel.org/all/7fb97184-baaa-4639-a0b9-ac289bf2e54d@igalia.com/
> >
> > Base on the original thread, I see that motivation of the patchset came
> > from a Syzkaller reported issue[1]. Can you try to run the reproducer
> > again and see if you can still get it to reproduce on the bpf-next tree?
>
> I just tested on bpf-next/master ("71b500afd2f7") and I couldn't
> reproduce the issue from Syzbot anymore. It seems that the branch
> causing the issue is pruned now, fixing the error in that case.
>
> But I still get the failures of the kselftests from patch 2/2:
>
> * verifier_bounds/deduce64_from_32_block_change:FAIL
> * verifier_bounds/deduce64_from_32_block_change_signed:FAIL
> *
> verifier_bounds/deduce64_from_32_block_change_conservative_signed:FAIL
> * verifier_bounds/deduce64_from_32_wrapping_32bit:FAIL
>
>
> How do you suggest we should proceed?
>

I still want this for the sake of improved value tracking.
Please give me a bit more time for review.