From d7091c2bbded22430db06e5172a3b4c3ee7f3cd8 Mon Sep 17 00:00:00 2001
From: Doug Kehn <rdkehn@yahoo.com>
Date: Wed, 14 Jul 2010 18:02:16 -0700
Subject: [PATCH] net/core: neighbour update Oops
commit 91a72a70594e5212c97705ca6a694bd307f7a26b upstream.
When configuring DMVPN (GRE + openNHRP) and a GRE remote
address is configured a kernel Oops is observed. The
obserseved Oops is caused by a NULL header_ops pointer
(neigh->dev->header_ops) in neigh_update_hhs() when
void (*update)(struct hh_cache*, const struct net_device*, const unsigned char *)
= neigh->dev->header_ops->cache_update;
is executed. The dev associated with the NULL header_ops is
the GRE interface. This patch guards against the
possibility that header_ops is NULL.
This Oops was first observed in kernel version 2.6.26.8.
Signed-off-by: Doug Kehn <rdkehn@yahoo.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
net/core/neighbour.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index e587e6819698..e69625084481 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -945,7 +945,10 @@ static void neigh_update_hhs(struct neighbour *neigh)
{
struct hh_cache *hh;
void (*update)(struct hh_cache*, const struct net_device*, const unsigned char *)
- = neigh->dev->header_ops->cache_update;
+ = NULL;
+
+ if (neigh->dev->header_ops)
+ update = neigh->dev->header_ops->cache_update;
if (update) {
for (hh = neigh->hh; hh; hh = hh->hh_next) {
--
2.34.1