Re: kernel panic: corrupted stack end in wb_workfn

From: Dmitry Vyukov
Date: Wed Mar 20 2019 - 09:59:36 EST


On Wed, Mar 20, 2019 at 11:59 AM Tetsuo Handa
<penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On 2019/03/20 19:42, Dmitry Vyukov wrote:
> >> I mean, yes, I agree, kernel bug bisection won't be perfect. But do
> >> you see anything actionable here?
>
> Allow users to manually tell bisection range when
> automatic bisection found a wrong commit.
>
> Also, allow users to specify reproducer program
> when automatic bisection found a wrong commit.
>
> Yes, this is anti automation. But since automation can't become perfect,
> I'm suggesting manual adjustment. Even if we involve manual adjustment,
> the syzbot's plenty CPU resources for building/testing kernels is highly
> appreciated (compared to doing manual bisection by building/testing kernels
> on personal PC environments).

FTR: provided an extended answer here:
https://groups.google.com/d/msg/syzkaller-bugs/1BSkmb_fawo/DOcDxv_KAgAJ


> > I see the larger long term bisection quality improvement (for syzbot
> > and for everybody else) in doing some actual testing for each kernel
> > commit before it's being merged into any kernel tree, so that we have
> > less of these a single program triggers 3 different bugs, stray
> > unrelated bugs, broken release boots, etc. I don't see how reliable
> > bisection is possible without that.
> >
>
> syzbot currently cannot test kernels with custom patches (unless "#syz test:" requests).
> Are you saying that syzbot will become be able to test kernels with custom patches?

I mean if we start improving kernel quality over time so that we have
less of these a single program triggers 3 different bugs, stray
unrelated bugs, broken release boots, etc, it will improve bisection
quality for everybody (beside being hugely useful in itself).