From 91a72a70594e5212c97705ca6a694bd307f7a26b Mon Sep 17 00:00:00 2001
From: Doug Kehn <rdkehn@yahoo.com>
Date: Wed, 14 Jul 2010 18:02:16 -0700
Subject: net/core: neighbour update Oops
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>
---
net/core/neighbour.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
(limited to 'net/core/neighbour.c')
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 6ba1c0eece03..a4e0a7482c2b 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -949,7 +949,10 @@ 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) {
--
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