queue-5.0/ipv4-recompile-ip-options-in-ipv4_link_failure.patch

   1 From foo@baz Sat Apr 20 16:43:09 CEST 2019
   2 From: Stephen Suryaputra <ssuryaextr@gmail.com>
   3 Date: Fri, 12 Apr 2019 16:19:27 -0400
   4 Subject: ipv4: recompile ip options in ipv4_link_failure
   5
   6 From: Stephen Suryaputra <ssuryaextr@gmail.com>
   7
   8 [ Upstream commit ed0de45a1008991fdaa27a0152befcb74d126a8b ]
   9
  10 Recompile IP options since IPCB may not be valid anymore when
  11 ipv4_link_failure is called from arp_error_report.
  12
  13 Refer to the commit 3da1ed7ac398 ("net: avoid use IPCB in cipso_v4_error")
  14 and the commit before that (9ef6b42ad6fd) for a similar issue.
  15
  16 Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
  17 Signed-off-by: David S. Miller <davem@davemloft.net>
  18 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  19 ---
  20  net/ipv4/route.c |   10 +++++++++-
  21  1 file changed, 9 insertions(+), 1 deletion(-)
  22
  23 --- a/net/ipv4/route.c
  24 +++ b/net/ipv4/route.c
  25 @@ -1186,8 +1186,16 @@ static struct dst_entry *ipv4_dst_check(
  26  static void ipv4_link_failure(struct sk_buff *skb)
  27  {
  28         struct rtable *rt;
  29 +       struct ip_options opt;
  30
  31 -       icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
  32 +       /* Recompile ip options since IPCB may not be valid anymore.
  33 +        */
  34 +       memset(&opt, 0, sizeof(opt));
  35 +       opt.optlen = ip_hdr(skb)->ihl*4 - sizeof(struct iphdr);
  36 +       if (__ip_options_compile(dev_net(skb->dev), &opt, skb, NULL))
  37 +               return;
  38 +
  39 +       __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt);
  40
  41         rt = skb_rtable(skb);
  42         if (rt)