releases/2.6.32.17/net-core-neighbour-update-oops.patch

   1 From 91a72a70594e5212c97705ca6a694bd307f7a26b Mon Sep 17 00:00:00 2001
   2 From: Doug Kehn <rdkehn@yahoo.com>
   3 Date: Wed, 14 Jul 2010 18:02:16 -0700
   4 Subject: net/core: neighbour update Oops
   5
   6 From: Doug Kehn <rdkehn@yahoo.com>
   7
   8 commit 91a72a70594e5212c97705ca6a694bd307f7a26b upstream.
   9
  10 When configuring DMVPN (GRE + openNHRP) and a GRE remote
  11 address is configured a kernel Oops is observed.  The
  12 obserseved Oops is caused by a NULL header_ops pointer
  13 (neigh->dev->header_ops) in neigh_update_hhs() when
  14
  15 void (*update)(struct hh_cache*, const struct net_device*, const unsigned char *)
  16 = neigh->dev->header_ops->cache_update;
  17
  18 is executed.  The dev associated with the NULL header_ops is
  19 the GRE interface.  This patch guards against the
  20 possibility that header_ops is NULL.
  21
  22 This Oops was first observed in kernel version 2.6.26.8.
  23
  24 Signed-off-by: Doug Kehn <rdkehn@yahoo.com>
  25 Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
  26 Signed-off-by: David S. Miller <davem@davemloft.net>
  27 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  28
  29 ---
  30  net/core/neighbour.c |    5 ++++-
  31  1 file changed, 4 insertions(+), 1 deletion(-)
  32
  33 --- a/net/core/neighbour.c
  34 +++ b/net/core/neighbour.c
  35 @@ -945,7 +945,10 @@ static void neigh_update_hhs(struct neig
  36  {
  37         struct hh_cache *hh;
  38         void (*update)(struct hh_cache*, const struct net_device*, const unsigned char *)
  39 -               = neigh->dev->header_ops->cache_update;
  40 +               = NULL;
  41 +
  42 +       if (neigh->dev->header_ops)
  43 +               update = neigh->dev->header_ops->cache_update;
  44
  45         if (update) {
  46                 for (hh = neigh->hh; hh; hh = hh->hh_next) {