From 9b46922e15f4d9d2aedcd320c3b7f7f54d956da7 Mon Sep 17 00:00:00 2001 From: Hong zhi guo Date: Sat, 23 Mar 2013 02:27:50 +0000 Subject: [PATCH] bridge: fix crash when set mac address of br interface When I tried to set mac address of a bridge interface to a mac address which already learned on this bridge, I got system hang. The cause is straight forward: function br_fdb_change_mac_address calls fdb_insert with NULL source nbp. Then an fdb lookup is performed. If an fdb entry is found and it's local, it's OK. But if it's not local, source is dereferenced for printk without NULL check. Signed-off-by: Hong Zhiguo Signed-off-by: David S. Miller --- net/bridge/br_fdb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c index b0812c91c0f0..bab338e6270d 100644 --- a/net/bridge/br_fdb.c +++ b/net/bridge/br_fdb.c @@ -423,7 +423,7 @@ static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source, return 0; br_warn(br, "adding interface %s with same address " "as a received packet\n", - source->dev->name); + source ? source->dev->name : br->dev->name); fdb_delete(br, fdb); }