Patch "ipv6: Should use consistent conditional judgement for ip6 fragment between __ip6_append_data and ip6_finish_output" has been added to the 4.4-stable tree

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

ipv6: Should use consistent conditional judgement for ip6 fragment between __ip6_append_data and ip6_finish_output

to the 4.4-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:
ipv6-should-use-consistent-conditional-judgement-for-ip6-fragment-between-__ip6_append_data-and-ip6_finish_output.patch
and it can be found in the queue-4.4 subdirectory.

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

From: Zheng Li <[email protected]>
Date: Wed, 28 Dec 2016 23:23:46 +0800
Subject: ipv6: Should use consistent conditional judgement for ip6 fragment between __ip6_append_data and ip6_finish_output

From: Zheng Li <[email protected]>

[ Upstream commit e4c5e13aa45c23692e4acf56f0b3533f328199b2 ]

There is an inconsistent conditional judgement between __ip6_append_data and ip6_finish_output functions, the variable length in __ip6_append_data just include the length of application's payload and udp6 header, don't include the length of ipv6 header, but in ip6_finish_output use (skb->len > ip6_skb_dst_mtu(skb)) as judgement, and skb->len include the length of ipv6 header.

That causes some particular application's udp6 payloads whose length are between (MTU - IPv6 Header) and MTU were fragmented by ip6_fragment even though the rst->dev support UFO feature.

Add the length of ipv6 header to length in __ip6_append_data to keep consistent conditional judgement as ip6_finish_output for ip6 fragment.

---
 net/ipv6/ip6_output.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -1361,7 +1361,7 @@ emsgsize:
 	 */
 
 	cork->length += length;
-	if (((length > mtu) ||
+	if ((((length + fragheaderlen) > mtu) ||
 	     (skb && skb_is_gso(skb))) &&
 	    (sk->sk_protocol == IPPROTO_UDP) &&
 	    (rt->dst.dev->features & NETIF_F_UFO) &&

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

queue-4.4/ipv6-should-use-consistent-conditional-judgement-for-ip6-fragment-between-__ip6_append_data-and-ip6_finish_output.patch