Merge tag 'net-5.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from xfrm and can.

  Current release - regressions:

   - rxrpc: restore removed timer deletion

  Current release - new code bugs:

   - gre: fix device lookup for l3mdev use-case

   - xfrm: fix egress device lookup for l3mdev use-case

  Previous releases - regressions:

   - sched: cls_u32: fix netns refcount changes in u32_change()

   - smc: fix sock leak when release after smc_shutdown()

   - xfrm: limit skb_page_frag_refill use to a single page

   - eth: atlantic: invert deep par in pm functions, preventing null
     derefs

   - eth: stmmac: use readl_poll_timeout_atomic() in atomic state

  Previous releases - always broken:

   - gre: fix skb_under_panic on xmit

   - openvswitch: fix OOB access in reserve_sfa_size()

   - dsa: hellcreek: calculate checksums in tagger

   - eth: ice: fix crash in switchdev mode

   - eth: igc:
      - fix infinite loop in release_swfw_sync
      - fix scheduling while atomic"

* tag 'net-5.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (37 commits)
  drivers: net: hippi: Fix deadlock in rr_close()
  selftests: mlxsw: vxlan_flooding_ipv6: Prevent flooding of unwanted packets
  selftests: mlxsw: vxlan_flooding: Prevent flooding of unwanted packets
  nfc: MAINTAINERS: add Bug entry
  net: stmmac: Use readl_poll_timeout_atomic() in atomic state
  doc/ip-sysctl: add bc_forwarding
  netlink: reset network and mac headers in netlink_dump()
  net: mscc: ocelot: fix broken IP multicast flooding
  net: dsa: hellcreek: Calculate checksums in tagger
  net: atlantic: invert deep par in pm functions, preventing null derefs
  can: isotp: stop timeout monitoring when no first frame was sent
  bonding: do not discard lowest hash bit for non layer3+4 hashing
  net: lan966x: Make sure to release ptp interrupt
  ipv6: make ip6_rt_gc_expire an atomic_t
  net: Handle l3mdev in ip_tunnel_init_flow
  l3mdev: l3mdev_master_upper_ifindex_by_index_rcu should be using netdev_master_upper_dev_get_rcu
  net/sched: cls_u32: fix possible leak in u32_init_knode()
  net/sched: cls_u32: fix netns refcount changes in u32_change()
  powerpc: Update MAINTAINERS for ibmvnic and VAS
  net: restore alpha order to Ethernet devices in config
  ...

1 files changed, 9 insertions, 5 deletions

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 8753e9cec326..976236736146 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -733,9 +733,6 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
 	else
 		fl6->daddr = tunnel->parms.raddr;
 
-	if (skb_cow_head(skb, dev->needed_headroom ?: tunnel->hlen))
-		return -ENOMEM;
-
 	/* Push GRE header. */
 	protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto;
 
@@ -743,6 +740,7 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
 		struct ip_tunnel_info *tun_info;
 		const struct ip_tunnel_key *key;
 		__be16 flags;
+		int tun_hlen;
 
 		tun_info = skb_tunnel_info_txcheck(skb);
 		if (IS_ERR(tun_info) ||
@@ -760,9 +758,12 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
 		dsfield = key->tos;
 		flags = key->tun_flags &
 			(TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
-		tunnel->tun_hlen = gre_calc_hlen(flags);
+		tun_hlen = gre_calc_hlen(flags);
 
-		gre_build_header(skb, tunnel->tun_hlen,
+		if (skb_cow_head(skb, dev->needed_headroom ?: tun_hlen + tunnel->encap_hlen))
+			return -ENOMEM;
+
+		gre_build_header(skb, tun_hlen,
 				 flags, protocol,
 				 tunnel_id_to_key32(tun_info->key.tun_id),
 				 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++)
@@ -772,6 +773,9 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
 		if (tunnel->parms.o_flags & TUNNEL_SEQ)
 			tunnel->o_seqno++;
 
+		if (skb_cow_head(skb, dev->needed_headroom ?: tunnel->hlen))
+			return -ENOMEM;
+
 		gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
 				 protocol, tunnel->parms.o_key,
 				 htonl(tunnel->o_seqno));