diff --git a/hadoop-yarn-project/CHANGES.txt b/hadoop-yarn-project/CHANGES.txt
index bccecbef59..a98a120fb1 100644
--- a/hadoop-yarn-project/CHANGES.txt
+++ b/hadoop-yarn-project/CHANGES.txt
@@ -53,6 +53,9 @@ Release 2.5.0 - UNRELEASED
     YARN-1923. Make Fair Scheduler resource ratio calculations terminate faster
     (Anubhav Dhoot via Sandy Ryza)
 
+    YARN-1870. FileInputStream is not closed in ProcfsBasedProcessTree#constructProcessSMAPInfo. 
+    (Fengdong Yu via junping_du)
+
   OPTIMIZATIONS
 
   BUG FIXES 
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/util/ProcfsBasedProcessTree.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/util/ProcfsBasedProcessTree.java
index 8073a1321c..eeb559c827 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/util/ProcfsBasedProcessTree.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/util/ProcfsBasedProcessTree.java
@@ -20,7 +20,6 @@
 
 import java.io.BufferedReader;
 import java.io.File;
-import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.FileReader;
 import java.io.IOException;
@@ -736,7 +735,7 @@ private static void constructProcessSMAPInfo(ProcessTreeSmapMemInfo pInfo,
       fReader = new FileReader(file);
       in = new BufferedReader(fReader);
       ProcessSmapMemoryInfo memoryMappingInfo = null;
-      List<String> lines = IOUtils.readLines(new FileInputStream(file));
+      List<String> lines = IOUtils.readLines(in);
       for (String line : lines) {
         line = line.trim();
         try {