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

[Ian Kumlien]

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.

> Thanks!
>
> Paolo
>