If there is no best neighbor, don't dereference the NULL pointer.
Introduced by 9bb33b8d88e318c4879d37d06ad28e3e018b9036 ("batman-adv: split tq information in neigh_node struct")
Signed-off-by: Simon Wunderlich sw@simonwunderlich.de --- originator.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/originator.c b/originator.c index 2243003..9fcde58 100644 --- a/originator.c +++ b/originator.c @@ -789,7 +789,7 @@ batadv_find_best_neighbor(struct batadv_priv *bat_priv, best, if_outgoing) <= 0)) best = neigh;
- if (!atomic_inc_not_zero(&best->refcount)) + if (best && !atomic_inc_not_zero(&best->refcount)) best = NULL; rcu_read_unlock();
On Tuesday 17 December 2013 16:35:13 Simon Wunderlich wrote:
If there is no best neighbor, don't dereference the NULL pointer.
Introduced by 9bb33b8d88e318c4879d37d06ad28e3e018b9036 ("batman-adv: split tq information in neigh_node struct")
Signed-off-by: Simon Wunderlich sw@simonwunderlich.de
originator.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/originator.c b/originator.c index 2243003..9fcde58 100644 --- a/originator.c +++ b/originator.c @@ -789,7 +789,7 @@ batadv_find_best_neighbor(struct batadv_priv *bat_priv, best, if_outgoing) <= 0)) best = neigh;
- if (!atomic_inc_not_zero(&best->refcount))
- if (best && !atomic_inc_not_zero(&best->refcount)) best = NULL; rcu_read_unlock();
Although this is a valid fix the approach could be improved. The for-loop should check whether the counter can be increased. Otherwise we might select a best-neighbor that is being purged and end up with no best despite having alternatives.
Cheers, Marek
b.a.t.m.a.n@lists.open-mesh.org
-
Marek Lindner -
Simon Wunderlich