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>
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 89ad25a..427f90a 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -475,11 +475,8 @@
{
struct net_bridge_port *p;
- if (!br_port_exists(dev))
- return -EINVAL;
-
p = br_port_get(dev);
- if (p->br != br)
+ if (!p || p->br != br)
return -EINVAL;
del_nbp(p);