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 4.9-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-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Fri Aug 4 13:32:40 PDT 2017 From: Zheng Li <james.z.li@xxxxxxxxxxxx> 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 <james.z.li@xxxxxxxxxxxx> [ 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. Signed-off-by: Zheng Li <james.z.li@xxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv6/ip6_output.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1376,7 +1376,7 @@ 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) && !rt->dst.header_len && Patches currently in stable-queue which might be from james.z.li@xxxxxxxxxxxx are queue-4.9/ipv6-should-use-consistent-conditional-judgement-for-ip6-fragment-between-__ip6_append_data-and-ip6_finish_output.patch