Messages in this thread | | | From | Eric Dumazet <> | Date | Wed, 22 Jun 2022 18:29:33 +0200 | Subject | Re: [PATCH net] net: ensure all external references are released in deferred skbuffs |
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On Wed, Jun 22, 2022 at 4:26 PM Ilya Maximets <i.maximets@ovn.org> wrote: > > On 6/22/22 13:43, Eric Dumazet wrote:
> > I tested the patch below and it seems to fix the issue seen > with OVS testsuite. Though it's not obvious for me why this > happens. Can you explain a bit more?
Anyway, I am not sure we can call nf_reset_ct(skb) that early.
git log seems to say that xfrm check needs to be done before nf_reset_ct(skb), I have no idea why.
I suspect some incoming packets are not going through xfrm4_policy_check() and end up being stored in a TCP receive queue.
Maybe something is missing before calling tcp_child_process()
> > > > > I note that IPv6 does the nf_reset_ct() earlier, from ip6_protocol_deliver_rcu() > > > > diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c > > index fda811a5251f2d76ac24a036e6b4f4e7d7d96d6f..a06464f96fe0cc94dd78272738ddaab2c19e87db > > 100644 > > --- a/net/ipv4/tcp_ipv4.c > > +++ b/net/ipv4/tcp_ipv4.c > > @@ -1919,6 +1919,8 @@ int tcp_v4_rcv(struct sk_buff *skb) > > struct sock *sk; > > int ret; > > > > + nf_reset_ct(skb); > > + > > drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; > > if (skb->pkt_type != PACKET_HOST) > > goto discard_it; > > @@ -2046,8 +2048,6 @@ int tcp_v4_rcv(struct sk_buff *skb) > > if (drop_reason) > > goto discard_and_relse; > > > > - nf_reset_ct(skb); > > - > > if (tcp_filter(sk, skb)) { > > drop_reason = SKB_DROP_REASON_SOCKET_FILTER; > > goto discard_and_relse; >
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