This is a note to let you know that I've just added the patch titled
net l2tp: drop flow hash on forward
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-l2tp-drop-flow-hash-on-forward.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d07c935da8b1e864459b6058789a3325162f2318
Author: David Bauer <mail@xxxxxxxxxxxxxxx>
Date: Wed Apr 24 19:11:10 2024 +0200
net l2tp: drop flow hash on forward
[ 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 <jchapman@xxxxxxxxxxx>
Signed-off-by: David Bauer <mail@xxxxxxxxxxxxxxx>
Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240424171110.13701-1-mail@xxxxxxxxxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
index 6cd97c75445c8..9a36e174984cf 100644
--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -136,6 +136,9 @@ 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);
