CME in AuthManager causes region server crash

java.util.ConcurrentModificationException
    at java.util.HashMap$HashIterator.nextNode(HashMap.java:1445)
    at java.util.HashMap$KeyIterator.next(HashMap.java:1469)
    at org.apache.hadoop.hbase.security.access.AuthManager.authorizeNamespace(AuthManager.java:313)
    at org.apache.hadoop.hbase.security.access.AuthManager.authorizeUserNamespace(AuthManager.java:297)
    at org.apache.hadoop.hbase.security.access.AuthManager.authorizeUserTable(AuthManager.java:405)
    at org.apache.hadoop.hbase.security.access.AuthManager.authorizeUserTable(AuthManager.java:372)
    at org.apache.hadoop.hbase.security.access.AccessChecker.permissionGranted(AccessChecker.java:711)
    at org.apache.hadoop.hbase.security.access.AccessController.permissionGranted(AccessController.java:325)
    at org.apache.hadoop.hbase.security.access.AccessController.internalPreRead(AccessController.java:1337)
    at org.apache.hadoop.hbase.security.access.AccessController.preGetOp(AccessController.java:1422)
    at org.apache.hadoop.hbase.regionserver.RegionCoprocessorHost$19.call(RegionCoprocessorHost.java:866)
    at org.apache.hadoop.hbase.regionserver.RegionCoprocessorHost$19.call(RegionCoprocessorHost.java:863)
    at org.apache.hadoop.hbase.coprocessor.CoprocessorHost$ObserverOperationWithoutResult.callObserver(CoprocessorHost.java:581)
    at org.apache.hadoop.hbase.coprocessor.CoprocessorHost.execOperation(CoprocessorHost.java:655)
    at org.apache.hadoop.hbase.regionserver.RegionCoprocessorHost.preGet(RegionCoprocessorHost.java:863)
    at org.apache.hadoop.hbase.regionserver.RSRpcServices.get(RSRpcServices.java:2905)
    at org.apache.hadoop.hbase.regionserver.RSRpcServices.get(RSRpcServices.java:2844)
    at org.apache.hadoop.hbase.shaded.protobuf.generated.ClientProtos$ClientService$2.callBlockingMethod(ClientProtos.java:42274)
    at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:458)
    at org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:133)
    at org.apache.hadoop.hbase.ipc.RpcExecutor$Handler.run(RpcExecutor.java:338)
    at org.apache.hadoop.hbase.ipc.RpcExecutor$Handler.run(RpcExecutor.java:318)