The upstream commit, 71d8c47fc653711c41bc3282e5b0e605b3727956 ("netfilter: conntrack: introduce clash resolution on insertion race"), sets allow_clash=true in the UDP/UDPLITE protocol handler but does not set it in the generic protocol handler. As a result, packets composed of connectionless protocols at each layer, such as UDP over IP-in-IP, still drop packets due to conflicts during conntrack insertion. To resolve this, this patch sets allow_clash in the nf_conntrack_l4proto_generic. Signed-off-by: Yuto Hamaguchi --- net/netfilter/nf_conntrack_proto_generic.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/netfilter/nf_conntrack_proto_generic.c b/net/netfilter/nf_conntrack_proto_generic.c index e831637bc8ca..cb260eb3d012 100644 --- a/net/netfilter/nf_conntrack_proto_generic.c +++ b/net/netfilter/nf_conntrack_proto_generic.c @@ -67,6 +67,7 @@ void nf_conntrack_generic_init_net(struct net *net) const struct nf_conntrack_l4proto nf_conntrack_l4proto_generic = { .l4proto = 255, + .allow_clash = true, #ifdef CONFIG_NF_CONNTRACK_TIMEOUT .ctnl_timeout = { .nlattr_to_obj = generic_timeout_nlattr_to_obj, -- 2.36.1