netdev - [PATCH net-next 08/10] veth: Call skb_metadata_set when skb->data points past metadata

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Message-Id: <20260110-skb-meta-fixup-skb_metadata_set-calls-v1-8-1047878ed1b0@cloudflare.com>
Date: Sat, 10 Jan 2026 22:05:22 +0100
From: Jakub Sitnicki <jakub@...udflare.com>
To: netdev@...r.kernel.org
Cc: "David S. Miller" <davem@...emloft.net>, 
 Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, 
 Paolo Abeni <pabeni@...hat.com>, Simon Horman <horms@...nel.org>, 
 Michael Chan <michael.chan@...adcom.com>, 
 Pavan Chebbi <pavan.chebbi@...adcom.com>, 
 Andrew Lunn <andrew+netdev@...n.ch>, 
 Tony Nguyen <anthony.l.nguyen@...el.com>, 
 Przemek Kitszel <przemyslaw.kitszel@...el.com>, 
 Saeed Mahameed <saeedm@...dia.com>, Leon Romanovsky <leon@...nel.org>, 
 Tariq Toukan <tariqt@...dia.com>, Mark Bloch <mbloch@...dia.com>, 
 Alexei Starovoitov <ast@...nel.org>, Daniel Borkmann <daniel@...earbox.net>, 
 Jesper Dangaard Brouer <hawk@...nel.org>, 
 John Fastabend <john.fastabend@...il.com>, 
 Stanislav Fomichev <sdf@...ichev.me>, intel-wired-lan@...ts.osuosl.org, 
 bpf@...r.kernel.org, kernel-team@...udflare.com
Subject: [PATCH net-next 08/10] veth: Call skb_metadata_set when skb->data
 points past metadata

Prepare to copy the XDP metadata into an skb extension in skb_metadata_set.

Unlike other drivers, veth calls skb_metadata_set after eth_type_trans,
which pulls the Ethernet header and moves skb->data. This violates the
new contract with skb_metadata.

Adjust the driver to pull the MAC header after calling skb_metadata_set.

Signed-off-by: Jakub Sitnicki <jakub@...udflare.com>
---
 drivers/net/veth.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 14e6f2a2fb77..1d1dbfa2e5ef 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -874,11 +874,11 @@ static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 	else
 		skb->data_len = 0;

-	skb->protocol = eth_type_trans(skb, rq->dev);
-
 	metalen = xdp->data - xdp->data_meta;
 	if (metalen)
 		skb_metadata_set(skb, metalen);
+
+	skb->protocol = eth_type_trans(skb, rq->dev);
 out:
 	return skb;
 drop:

-- 
2.43.0