From c80123ba3fbb7b40566354f54eba4c01f544b1b4 Mon Sep 17 00:00:00 2001 From: Doug Kehn 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 Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- 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 bff37908bd55..7d5310513bdc 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -948,7 +948,10 @@ 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) { -- 2.39.5