From f4ad6ba684ea81a99305845b46c8a191ddd67fda Mon Sep 17 00:00:00 2001 From: David Bauer Date: Wed, 24 Apr 2024 19:11:10 +0200 Subject: [PATCH] net l2tp: drop flow hash on forward BugLink: https://bugs.launchpad.net/bugs/2070349 [ Upstream commit 42f853b42899d9b445763b55c3c8adc72be0f0e1 ] Drop the flow-hash of the skb when forwarding to the L2TP netdev. This avoids the L2TP qdisc from using the flow-hash from the outer packet, which is identical for every flow within the tunnel. This does not affect every platform but is specific for the ethernet driver. It depends on the platform including L4 information in the flow-hash. One such example is the Mediatek Filogic MT798x family of networking processors. Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support") Acked-by: James Chapman Signed-off-by: David Bauer Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20240424171110.13701-1-mail@david-bauer.net Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin Signed-off-by: Manuel Diewald Signed-off-by: Stefan Bader --- net/l2tp/l2tp_eth.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c index 25ca89f80414..9dacfa91acc7 100644 --- a/net/l2tp/l2tp_eth.c +++ b/net/l2tp/l2tp_eth.c @@ -127,6 +127,9 @@ static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, /* checksums verified by L2TP */ skb->ip_summed = CHECKSUM_NONE; + /* drop outer flow-hash */ + skb_clear_hash(skb); + skb_dst_drop(skb); nf_reset_ct(skb);