Re: [syzbot] [bpf?] WARNING: ODEBUG bug in tcx_uninstall

[Martin KaFai Lau]

On 7/26/23 10:01 AM, Leon Romanovsky wrote:
> On Wed, Jul 26, 2023 at 08:23:12AM -0700, Jakub Kicinski wrote:
> > On Wed, 26 Jul 2023 10:12:54 +0300 Leon Romanovsky wrote:
> > > > Thanks, I'll take a look this evening.
> > >
> > > Did anybody post a fix for that?
> > >
> > > We are experiencing the following kernel panic in netdev commit
> > > b57e0d48b300 (net-next/main) Merge branch '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue
> >
> > Not that I know, looks like this is with Daniel's previous fix already
> > present, and syzbot is hitting it, too :(
>
> My naive workaround which restored our regression runs is:
>
> diff --git a/kernel/bpf/tcx.c b/kernel/bpf/tcx.c
> index 69a272712b29..10c9ab830702 100644
> --- a/kernel/bpf/tcx.c
> +++ b/kernel/bpf/tcx.c
> @@ -111,6 +111,7 @@ void tcx_uninstall(struct net_device *dev, bool ingress)
>                          bpf_prog_put(tuple.prog);
>                  tcx_skeys_dec(ingress);
>          }
> -       WARN_ON_ONCE(tcx_entry(entry)->miniq_active);
> +       tcx_miniq_set_active(entry, false);

Thanks for the report. I will look into it.

>          tcx_entry_free(entry);
>   }