Re: [Intel-wired-lan] bug with rx-udp-gro-forwarding offloading?

[Ian Kumlien]

On Tue, Jul 4, 2023 at 3:41 PM Paolo Abeni <pabeni@xxxxxxxxxx> wrote:
>
> On Tue, 2023-07-04 at 15:23 +0200, Ian Kumlien wrote:
> > On Tue, Jul 4, 2023 at 2:54 PM Paolo Abeni <pabeni@xxxxxxxxxx> wrote:
> > >
> > > On Tue, 2023-07-04 at 13:36 +0200, Ian Kumlien wrote:
> > > > Propper bug this time:
> > > > cat bug.txt | ./scripts/decode_stacktrace.sh vmlinux
> > >
> > > To be sure, is this with the last patch I shared? this one I mean:
> >
> > The current modifications I have, on top of v6.4.1, is:
> > diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> > index cea28d30abb5..8552caa197f9 100644
> > --- a/net/core/skbuff.c
> > +++ b/net/core/skbuff.c
> > @@ -4272,6 +4272,11 @@ struct sk_buff *skb_segment_list(struct sk_buff *skb,
> >
> >         skb_shinfo(skb)->frag_list = NULL;
> >
> > +       /* later code will clear the gso area in the shared info */
> > +       err = skb_header_unclone(skb, GFP_ATOMIC);
> > +       if (err)
> > +               goto err_linearize;
> > +
> >         while (list_skb) {
> >                 nskb = list_skb;
> >                 list_skb = list_skb->next;
> > @@ -4328,6 +4333,9 @@ struct sk_buff *skb_segment_list(struct sk_buff *skb,
> >
> >         skb->prev = tail;
> >
> > +       if (WARN_ON_ONCE(!skb->next))
> > +               goto err_linearize;
> > +
> >         if (skb_needs_linearize(skb, features) &&
> >             __skb_linearize(skb))
> >                 goto err_linearize;
> > ---
> >
> > > https://lore.kernel.org/netdev/92a4d42491a2c219192ae86fa04b579ea3676d8c.camel@xxxxxxxxxx/
> > >
> > > Could you please additionally enable CONFIG_DEBUG_NET in your build?
> >
> > Sure, will do
> >
> > > Could you please give a detailed description of your network topology
> > > and the running traffic?
> >
> > This machine has two "real interfaces" and two interfaces that runs as
> > bridges for virtual machines
> > eno1 - real internal
> > eno2 - bridge - internal
> > eno3 - real external
> > eno4 - bridge - external
> >
> > The bridges are used by three virtual machines, two of which are
> > attached on both networks
> >
> > Traffic seemed to be video streaming, at least at first, now I don't
> > really know. I do have a few smart devices so I assume there is
> > a bit of multicast traffic as well - but not really anything unusual as such.
>
> In there any XDP program running on the host side? Possibly changing
> the packet hdr?

Only systemd standard things, I haven't done anything and the normal
nftables fw doesn't do anything special

> Thanks!
>
> /P
>