git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From foo@baz Fri Aug  4 13:32:40 PDT 2017
   2 From: Zheng Li <james.z.li@ericsson.com>
   3 Date: Wed, 28 Dec 2016 23:23:46 +0800
   4 Subject: ipv6: Should use consistent conditional judgement for ip6 fragment between __ip6_append_data and ip6_finish_output
   5
   6 From: Zheng Li <james.z.li@ericsson.com>
   7
   8
   9 [ Upstream commit e4c5e13aa45c23692e4acf56f0b3533f328199b2 ]
  10
  11 There is an inconsistent conditional judgement between __ip6_append_data
  12 and ip6_finish_output functions, the variable length in __ip6_append_data
  13 just include the length of application's payload and udp6 header, don't
  14 include the length of ipv6 header, but in ip6_finish_output use
  15 (skb->len > ip6_skb_dst_mtu(skb)) as judgement, and skb->len include the
  16 length of ipv6 header.
  17
  18 That causes some particular application's udp6 payloads whose length are
  19 between (MTU - IPv6 Header) and MTU were fragmented by ip6_fragment even
  20 though the rst->dev support UFO feature.
  21
  22 Add the length of ipv6 header to length in __ip6_append_data to keep
  23 consistent conditional judgement as ip6_finish_output for ip6 fragment.
  24
  25 Signed-off-by: Zheng Li <james.z.li@ericsson.com>
  26 Signed-off-by: David S. Miller <davem@davemloft.net>
  27 Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
  28 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  29 ---
  30  net/ipv6/ip6_output.c |    2 +-
  31  1 file changed, 1 insertion(+), 1 deletion(-)
  32
  33 --- a/net/ipv6/ip6_output.c
  34 +++ b/net/ipv6/ip6_output.c
  35 @@ -1376,7 +1376,7 @@ emsgsize:
  36          */
  37
  38         cork->length += length;
  39 -       if (((length > mtu) ||
  40 +       if ((((length + fragheaderlen) > mtu) ||
  41              (skb && skb_is_gso(skb))) &&
  42             (sk->sk_protocol == IPPROTO_UDP) &&
  43             (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len &&