diff options
| author | stephen hemminger <shemminger@vyatta.com> | 2010-11-15 06:38:13 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-11-15 11:13:17 -0800 |
| commit | b5ed54e94d324f17c97852296d61a143f01b227a (patch) | |
| tree | 2104d3cde24efc1145bc71beb4b61d79ed841132 /net/bridge/br_fdb.c | |
| parent | 61391cde9eefac5cfcf6d214aa80c77e58b1626b (diff) | |
| download | linux-b5ed54e94d324f17c97852296d61a143f01b227a.tar.gz linux-b5ed54e94d324f17c97852296d61a143f01b227a.tar.bz2 linux-b5ed54e94d324f17c97852296d61a143f01b227a.zip | |
bridge: fix RCU races with bridge port
The macro br_port_exists() is not enough protection when only
RCU is being used. There is a tiny race where other CPU has cleared port
handler hook, but is bridge port flag might still be set.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/bridge/br_fdb.c')
| -rw-r--r-- | net/bridge/br_fdb.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c index 90512ccfd3e9..2872393b2939 100644 --- a/net/bridge/br_fdb.c +++ b/net/bridge/br_fdb.c @@ -238,15 +238,18 @@ struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br, int br_fdb_test_addr(struct net_device *dev, unsigned char *addr) { struct net_bridge_fdb_entry *fdb; + struct net_bridge_port *port; int ret; - if (!br_port_exists(dev)) - return 0; - rcu_read_lock(); - fdb = __br_fdb_get(br_port_get_rcu(dev)->br, addr); - ret = fdb && fdb->dst->dev != dev && - fdb->dst->state == BR_STATE_FORWARDING; + port = br_port_get_rcu(dev); + if (!port) + ret = 0; + else { + fdb = __br_fdb_get(port->br, addr); + ret = fdb && fdb->dst->dev != dev && + fdb->dst->state == BR_STATE_FORWARDING; + } rcu_read_unlock(); return ret; |