Merge tag 'ipsec-2025-05-21' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

Steffen Klassert says:

====================
pull request (net): ipsec 2025-05-21

1) Fix some missing kfree_skb in the error paths of espintcp.
   From Sabrina Dubroca.

2) Fix a reference leak in espintcp.
   From Sabrina Dubroca.

3) Fix UDP GRO handling for ESPINUDP.
   From Tobias Brunner.

4) Fix ipcomp truesize computation on the receive path.
   From Sabrina Dubroca.

5) Sanitize marks before policy/state insertation.
   From Paul Chaignon.

* tag 'ipsec-2025-05-21' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec:
  xfrm: Sanitize marks before insert
  xfrm: ipcomp: fix truesize computation on receive
  xfrm: Fix UDP GRO handling for some corner cases
  espintcp: remove encap socket caching to avoid reference leak
  espintcp: fix skb leaks
====================

Link: https://patch.msgid.link/20250521054348.4057269-1-steffen.klassert@secunet.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 10 insertions, 8 deletions

diff --git a/net/ipv6/xfrm6_input.c b/net/ipv6/xfrm6_input.c
index 4abc5e9d6322..841c81abaaf4 100644
--- a/net/ipv6/xfrm6_input.c
+++ b/net/ipv6/xfrm6_input.c
@@ -179,14 +179,18 @@ struct sk_buff *xfrm6_gro_udp_encap_rcv(struct sock *sk, struct list_head *head,
 	int offset = skb_gro_offset(skb);
 	const struct net_offload *ops;
 	struct sk_buff *pp = NULL;
-	int ret;
+	int len, dlen;
+	__u8 *udpdata;
+	__be32 *udpdata32;
 
 	if (skb->protocol == htons(ETH_P_IP))
 		return xfrm4_gro_udp_encap_rcv(sk, head, skb);
 
-	offset = offset - sizeof(struct udphdr);
-
-	if (!pskb_pull(skb, offset))
+	len = skb->len - offset;
+	dlen = offset + min(len, 8);
+	udpdata = skb_gro_header(skb, dlen, offset);
+	udpdata32 = (__be32 *)udpdata;
+	if (unlikely(!udpdata))
 		return NULL;
 
 	rcu_read_lock();
@@ -194,11 +198,10 @@ struct sk_buff *xfrm6_gro_udp_encap_rcv(struct sock *sk, struct list_head *head,
 	if (!ops || !ops->callbacks.gro_receive)
 		goto out;
 
-	ret = __xfrm6_udp_encap_rcv(sk, skb, false);
-	if (ret)
+	/* check if it is a keepalive or IKE packet */
+	if (len <= sizeof(struct ip_esp_hdr) || udpdata32[0] == 0)
 		goto out;
 
-	skb_push(skb, offset);
 	NAPI_GRO_CB(skb)->proto = IPPROTO_UDP;
 
 	pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
@@ -208,7 +211,6 @@ struct sk_buff *xfrm6_gro_udp_encap_rcv(struct sock *sk, struct list_head *head,
 
 out:
 	rcu_read_unlock();
-	skb_push(skb, offset);
 	NAPI_GRO_CB(skb)->same_flow = 0;
 	NAPI_GRO_CB(skb)->flush = 1;