Patch "ip6_tunnel: update mtu properly for ARPHRD_ETHER tunnel device in tx path" has been added to the 4.13-stable tree

This is a note to let you know that I've just added the patch titled

ip6_tunnel: update mtu properly for ARPHRD_ETHER tunnel device in tx path

to the 4.13-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:
ip6_tunnel-update-mtu-properly-for-arphrd_ether-tunnel-device-in-tx-path.patch
and it can be found in the queue-4.13 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Xin Long <[email protected]>
Date: Thu, 28 Sep 2017 13:24:07 +0800
Subject: ip6_tunnel: update mtu properly for ARPHRD_ETHER tunnel device in tx path

From: Xin Long <[email protected]>

[ Upstream commit d41bb33ba33b8f8debe54ed36be6925eb496e354 ]

Now when updating mtu in tx path, it doesn't consider ARPHRD_ETHER tunnel device, like ip6gre_tap tunnel, for which it should also subtract ether header to get the correct mtu.

---
 net/ipv6/ip6_tunnel.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

@@ -1043,6 +1043,7 @@ int ip6_tnl_xmit(struct sk_buff *skb, st
 	struct dst_entry *dst = NULL, *ndst = NULL;
 	struct net_device *tdev;
 	int mtu;
+	unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
 	unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
 	unsigned int max_headroom = psh_hlen;
 	bool use_cache = false;

@@ -1124,7 +1125,7 @@ route_lookup:
 				     t->parms.name);
 		goto tx_err_dst_release;
 	}
-	mtu = dst_mtu(dst) - psh_hlen - t->tun_hlen;
+	mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
 	if (encap_limit >= 0) {
 		max_headroom += 8;
 		mtu -= 8;

@@ -1133,7 +1134,7 @@ route_lookup:
 		mtu = IPV6_MIN_MTU;
 	if (skb_dst(skb) && !t->parms.collect_md)
 		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
-	if (skb->len - t->tun_hlen > mtu && !skb_is_gso(skb)) {
+	if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
 		*pmtu = mtu;
 		err = -EMSGSIZE;
 		goto tx_err_dst_release;

Patches currently in stable-queue which might be from [email protected] are

queue-4.13/ip6_tunnel-do-not-allow-loading-ip6_tunnel-if-ipv6-is-disabled-in-cmdline.patch queue-4.13/ip6_gre-ip6gre_tap-device-should-keep-dst.patch queue-4.13/ip6_gre-skb_push-ipv6hdr-before-packing-the-header-in-ip6gre_header.patch queue-4.13/ip6_tunnel-update-mtu-properly-for-arphrd_ether-tunnel-device-in-tx-path.patch