diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index f7de942c6db..882ab5ea7bc 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -269,6 +269,9 @@ Trunk (Unreleased)
     HADOOP-9433 TestLocalFileSystem#testHasFileDescriptor leaks file handle
     (Chris Nauroth via sanjay)
 
+    HADOOP-9806 PortmapInterface should check if the procedure is out-of-range
+    (brandonli)
+
   OPTIMIZATIONS
 
     HADOOP-7761. Improve the performance of raw comparisons. (todd)
diff --git a/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/portmap/PortmapInterface.java b/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/portmap/PortmapInterface.java
index 26d3d774647..ae968cb046d 100644
--- a/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/portmap/PortmapInterface.java
+++ b/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/portmap/PortmapInterface.java
@@ -45,6 +45,9 @@ public interface PortmapInterface {
     }
     
     public static Procedure fromValue(int value) {
+      if (value < 0 || value >= values().length) {
+        return null;
+      }
       return values()[value];
     }
   }
diff --git a/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/portmap/RpcProgramPortmap.java b/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/portmap/RpcProgramPortmap.java
index cbf381296a7..c715d33e3cb 100644
--- a/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/portmap/RpcProgramPortmap.java
+++ b/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/portmap/RpcProgramPortmap.java
@@ -131,29 +131,22 @@ public class RpcProgramPortmap extends RpcProgram implements PortmapInterface {
   @Override
   public XDR handleInternal(RpcCall rpcCall, XDR in, XDR out,
       InetAddress client, Channel channel) {
-    Procedure procedure = Procedure.fromValue(rpcCall.getProcedure());
+    final Procedure portmapProc = Procedure.fromValue(rpcCall.getProcedure());
     int xid = rpcCall.getXid();
-    switch (procedure) {
-    case PMAPPROC_NULL:
+    if (portmapProc == Procedure.PMAPPROC_NULL) {
       out = nullOp(xid, in, out);
-      break;
-    case PMAPPROC_SET:
+    } else if (portmapProc == Procedure.PMAPPROC_SET) {
       out = set(xid, in, out);
-      break;
-    case PMAPPROC_UNSET:
+    } else if (portmapProc == Procedure.PMAPPROC_UNSET) {
       out = unset(xid, in, out);
-      break;
-    case PMAPPROC_DUMP:
+    } else if (portmapProc == Procedure.PMAPPROC_DUMP) {
       out = dump(xid, in, out);
-      break;
-    case PMAPPROC_GETPORT:
+    } else if (portmapProc == Procedure.PMAPPROC_GETPORT) {
       out = getport(xid, in, out);
-      break;
-    case PMAPPROC_GETVERSADDR:
+    } else if (portmapProc == Procedure.PMAPPROC_GETVERSADDR) {
       out = getport(xid, in, out);
-      break;
-    default:
-      LOG.info("PortmapHandler unknown rpc procedure=" + procedure);
+    } else {
+      LOG.info("PortmapHandler unknown rpc procedure=" + portmapProc);
       RpcAcceptedReply.voidReply(out, xid,
           RpcAcceptedReply.AcceptState.PROC_UNAVAIL);
     }