From 7b36e8eef989fc59535b4f1d3fc0f83afaf419d4 Mon Sep 17 00:00:00 2001 From: Marek Lindner Date: Fri, 18 Feb 2011 12:28:10 +0000 Subject: batman-adv: Correct rcu refcounting for orig_node It might be possible that 2 threads access the same data in the same rcu grace period. The first thread calls call_rcu() to decrement the refcount and free the data while the second thread increases the refcount to use the data. To avoid this race condition all refcount operations have to be atomic. Reported-by: Sven Eckelmann Signed-off-by: Marek Lindner --- net/batman-adv/routing.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) (limited to 'net/batman-adv/routing.c') diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index fc4c12a049da..9863c03a2137 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -420,7 +420,7 @@ static void update_orig(struct bat_priv *bat_priv, neigh_node = create_neighbor(orig_node, orig_tmp, ethhdr->h_source, if_incoming); - kref_put(&orig_tmp->refcount, orig_node_free_ref); + orig_node_free_ref(orig_tmp); if (!neigh_node) goto unlock; @@ -604,7 +604,7 @@ static char count_real_packets(struct ethhdr *ethhdr, out: spin_unlock_bh(&orig_node->ogm_cnt_lock); - kref_put(&orig_node->refcount, orig_node_free_ref); + orig_node_free_ref(orig_node); return ret; } @@ -730,7 +730,7 @@ void receive_bat_packet(struct ethhdr *ethhdr, bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: " "originator packet from myself (via neighbor)\n"); - kref_put(&orig_neigh_node->refcount, orig_node_free_ref); + orig_node_free_ref(orig_neigh_node); return; } @@ -835,10 +835,10 @@ void receive_bat_packet(struct ethhdr *ethhdr, 0, hna_buff_len, if_incoming); out_neigh: - if (!is_single_hop_neigh) - kref_put(&orig_neigh_node->refcount, orig_node_free_ref); + if ((orig_neigh_node) && (!is_single_hop_neigh)) + orig_node_free_ref(orig_neigh_node); out: - kref_put(&orig_node->refcount, orig_node_free_ref); + orig_node_free_ref(orig_node); } int recv_bat_packet(struct sk_buff *skb, struct batman_if *batman_if) @@ -952,7 +952,7 @@ out: if (neigh_node) neigh_node_free_ref(neigh_node); if (orig_node) - kref_put(&orig_node->refcount, orig_node_free_ref); + orig_node_free_ref(orig_node); return ret; } @@ -1028,7 +1028,7 @@ out: if (neigh_node) neigh_node_free_ref(neigh_node); if (orig_node) - kref_put(&orig_node->refcount, orig_node_free_ref); + orig_node_free_ref(orig_node); return ret; } @@ -1134,7 +1134,7 @@ out: if (neigh_node) neigh_node_free_ref(neigh_node); if (orig_node) - kref_put(&orig_node->refcount, orig_node_free_ref); + orig_node_free_ref(orig_node); return ret; } @@ -1189,7 +1189,7 @@ struct neigh_node *find_router(struct bat_priv *bat_priv, if (!primary_orig_node) goto return_router; - kref_put(&primary_orig_node->refcount, orig_node_free_ref); + orig_node_free_ref(primary_orig_node); } /* with less than 2 candidates, we can't do any @@ -1401,7 +1401,7 @@ out: if (neigh_node) neigh_node_free_ref(neigh_node); if (orig_node) - kref_put(&orig_node->refcount, orig_node_free_ref); + orig_node_free_ref(orig_node); return ret; } @@ -1543,7 +1543,7 @@ spin_unlock: spin_unlock_bh(&bat_priv->orig_hash_lock); out: if (orig_node) - kref_put(&orig_node->refcount, orig_node_free_ref); + orig_node_free_ref(orig_node); return ret; } -- cgit v1.2.2