Re: [syzbot] WARNING in __nf_unregister_net_hook (4)

[Dmitry Vyukov]

On Thu, May 13, 2021 at 2:56 AM Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> wrote:
>
> On Sat, May 08, 2021 at 04:46:57PM +0200, Florian Westphal wrote:
> > Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
> > > > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > > > Reported-by: syzbot+154bd5be532a63aa778b@xxxxxxxxxxxxxxxxxxxxxxxxx
> > >
> > > Is this also fixed by "netfilter: arptables: use pernet ops struct
> > > during unregister"?
> > > The warning is the same, but the stack is different...
> >
> > No, this is a different bug.
> >
> > In both cases the caller attempts to unregister a hook that the core
> > can't find, but in this case the caller is nftables, not arptables.
>
> I see no reproducer for this bug. Maybe I broke the dormant flag handling?
>
> Or maybe syzbot got here after the arptables bug has been hitted?

syzbot always stops after the first bug to give you perfect "Not
tainted" oopses.