tipc: make media_ptr pointed netdevice valid
The 'media_ptr' pointer in bearer structure which points to network
device, is protected by RCU. So, before netdevice is released,
synchronize_net() should be involved to prevent no any user of
the netdevice on read side from accessing it after it is freed.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Tested-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 1bd96eb..402e994 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -471,6 +471,7 @@
dev = (struct net_device *)rtnl_dereference(b->media_ptr);
RCU_INIT_POINTER(b->media_ptr, NULL);
RCU_INIT_POINTER(dev->tipc_ptr, NULL);
+ synchronize_net();
dev_put(dev);
}