This is a note to let you know that I've just added the patch titled
ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data and ip_finish_output
to the 3.18-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:
ipv4-should-use-consistent-conditional-judgement-for-ip-fragment-in-__ip_append_data-and-ip_finish_output.patch
and it can be found in the queue-3.18 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 Wed Aug 9 12:42:27 PDT 2017
From: zheng li <james.z.li@xxxxxxxxxxxx>
Date: Mon, 12 Dec 2016 09:56:05 +0800
Subject: ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data and ip_finish_output
From: zheng li <james.z.li@xxxxxxxxxxxx>
[ Upstream commit 0a28cfd51e17f4f0a056bcf66bfbe492c3b99f38 ]
There is an inconsistent conditional judgement in __ip_append_data and
ip_finish_output functions, the variable length in __ip_append_data just
include the length of application's payload and udp header, don't include
the length of ip header, but in ip_finish_output use
(skb->len > ip_skb_dst_mtu(skb)) as judgement, and skb->len include the
length of ip header.
That causes some particular application's udp payload whose length is
between (MTU - IP Header) and MTU were fragmented by ip_fragment even
though the rst->dev support UFO feature.
Add the length of ip header to length in __ip_append_data to keep
consistent conditional judgement as ip_finish_output for ip 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/ipv4/ip_output.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -888,7 +888,7 @@ static int __ip_append_data(struct sock
csummode = CHECKSUM_PARTIAL;
cork->length += length;
- if (((length > mtu) || (skb && skb_is_gso(skb))) &&
+ 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 &&
(sk->sk_type == SOCK_DGRAM)) {
Patches currently in stable-queue which might be from james.z.li@xxxxxxxxxxxx are
queue-3.18/ipv4-should-use-consistent-conditional-judgement-for-ip-fragment-in-__ip_append_data-and-ip_finish_output.patch
queue-3.18/ipv6-should-use-consistent-conditional-judgement-for-ip6-fragment-between-__ip6_append_data-and-ip6_finish_output.patch