HADOOP-11056. OsSecureRandom.setConf() might leak file descriptors. Contributed by Yongjun Zhang.

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -684,6 +684,9 @@ Release 2.6.0 - UNRELEASED
     HADOOP-8815. RandomDatum needs to override hashCode().
     (Brandon Li via suresh)
 
+    HADOOP-11056. OsSecureRandom.setConf() might leak file descriptors (yzhang
+    via cmccabe)
+
     BREAKDOWN OF HDFS-6134 AND HADOOP-10150 SUBTASKS AND RELATED JIRAS
   
       HADOOP-10734. Implement high-performance secure random number sources.

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/random/OsSecureRandom.java

@@ -23,6 +23,8 @@ import java.io.FileInputStream;
 import java.io.IOException;
 import java.util.Random;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configurable;
 import org.apache.hadoop.conf.Configuration;
@@ -37,6 +39,8 @@ import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.HADOOP_SECURITY
  */
 @InterfaceAudience.Private
 public class OsSecureRandom extends Random implements Closeable, Configurable {
+  public static final Log LOG = LogFactory.getLog(OsSecureRandom.class);
+  
   private static final long serialVersionUID = 6391500337172057900L;
 
   private transient Configuration conf;
@@ -72,12 +76,20 @@ public class OsSecureRandom extends Random implements Closeable, Configurable {
         HADOOP_SECURITY_SECURE_RANDOM_DEVICE_FILE_PATH_KEY,
         HADOOP_SECURITY_SECURE_RANDOM_DEVICE_FILE_PATH_DEFAULT);
     File randomDevFile = new File(randomDevPath);
+
     try {
+      close();
       this.stream = new FileInputStream(randomDevFile);
-      fillReservoir(0);
     } catch (IOException e) {
       throw new RuntimeException(e);
     }
+
+    try {
+      fillReservoir(0);
+    } catch (RuntimeException e) {
+      close();
+      throw e;
+    }
   }
 
   @Override
@@ -109,7 +121,10 @@ public class OsSecureRandom extends Random implements Closeable, Configurable {
   }
 
   @Override
-  synchronized public void close() throws IOException {
-    stream.close();
+  synchronized public void close() {
+    if (stream != null) {
+      IOUtils.cleanup(LOG, stream);
+      stream = null;
+    }
   }
 }

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/crypto/random/TestOsSecureRandom.java

@@ -22,6 +22,7 @@ import java.util.Arrays;
 
 import org.apache.commons.lang.SystemUtils;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.util.Shell.ShellCommandExecutor;
 import org.junit.Assume;
 import org.junit.Test;
 
@@ -136,4 +137,18 @@ public class TestOsSecureRandom {
     }
     random.close();
   }
+  
+  @Test(timeout=120000)
+  public void testOsSecureRandomSetConf() throws IOException {
+    Assume.assumeTrue(SystemUtils.IS_OS_LINUX);
+    OsSecureRandom random = new OsSecureRandom();
+    for(int n = 0; n < 10; ++n) {
+      random.setConf(new Configuration());
+      String[] scmd = new String[] {"/bin/sh", "-c", "lsof | wc -l"};
+      ShellCommandExecutor sce = new ShellCommandExecutor(scmd);
+      sce.execute(); 
+      System.out.println("==lsof result " + n + ":");
+      System.out.println(sce.getOutput());
+    }
+  }
 }