undefect. CWE-407 — 63 sites patched across 27 ecosystems

Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com

Patches, unit tests, benchmarks, whitepaper, and outreach briefs.
Public domain — no copyright claimed. Use freely.

test/jdk/java/util/logging/TestLoggerWeakRefLeak.java

@@ -0,0 +1,166 @@
+/*
+ * Copyright (c) 2010, 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.io.BufferedReader;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+
+import static jdk.test.lib.Asserts.assertGreaterThan;
+import jdk.test.lib.process.ProcessTools;
+
+import com.sun.tools.attach.AttachNotSupportedException;
+import com.sun.tools.attach.VirtualMachine;
+
+import sun.tools.attach.HotSpotVirtualMachine;
+
+/*
+ * @test
+ * @bug 6942989
+ * @summary Check for WeakReference leak in Logger and anonymous Logger objects
+ * @library /test/lib
+ * @modules jdk.attach/sun.tools.attach
+ *          java.logging
+ * @build jdk.test.lib.process.ProcessTools
+ * @run main/othervm -Djdk.attach.allowAttachSelf TestLoggerWeakRefLeak Logger
+ * @run main/othervm -Djdk.attach.allowAttachSelf TestLoggerWeakRefLeak AnonymousLogger
+ */
+public class TestLoggerWeakRefLeak {
+
+    private static final String TARGET_CLASS = "java.lang.ref.WeakReference";
+    private static final int INSTANCE_COUNT = 100;
+    private static int loggerCount = 0;
+
+    public static void main(String[] args) throws Exception {
+        if (args[0].equals("AnonymousLogger")) {
+            System.out.println("Test for WeakReference leak in AnonymousLogger object");
+            testIfLeaking(TestLoggerWeakRefLeak::callAnonymousLogger);
+        } else {
+            System.out.println("Test for WeakReference leak in Logger object");
+            testIfLeaking(TestLoggerWeakRefLeak::callLogger);
+        }
+    }
+
+    /**
+     * For these particular WeakReference leaks, the count was always observed
+     * to be increasing so if decreasing or the same count is observed,
+     * then there is no leak.
+     */
+    private static void testIfLeaking(Runnable callLogger) throws Exception {
+        long count = 0;
+        int instanceCount = 0;
+        int previousInstanceCount = 0;
+        int increasingCount = 0;
+        int decreasingCount = 0;
+
+        while (true) {
+            callLogger.run();
+            count += INSTANCE_COUNT;
+
+            if ((count % 1000) == 0) {
+                System.out.println("call count = " + count);
+
+                instanceCount = getInstanceCountFromHeapHisto();
+                if (instanceCount > previousInstanceCount) {
+                    increasingCount++;
+                } else {
+                    decreasingCount++;
+                    System.out.println("increasing count: " + increasingCount);
+                    System.out.println("decreasing or the same count: " + decreasingCount);
+                    System.out.println("Test passed: decreasing or the same instance count is observed");
+                    break;
+                }
+                previousInstanceCount = instanceCount;
+            }
+
+            delayExecution();
+        }
+    }
+
+    /**
+     * This Logger call is leaking two different WeakReferences:
+     * - one in LogManager.LogNode
+     * - one in Logger.kids
+     */
+    private static void callLogger() {
+        for (int i = 0; i < INSTANCE_COUNT; i++) {
+            java.util.logging.Logger.getLogger("logger-" + loggerCount);
+            if (++loggerCount >= 25000) {
+                // Limit the Logger namespace used by the test so the weak refs
+                // in LogManager.loggers that are being properly managed
+                // don't skew the counts by too much.
+                loggerCount = 0;
+            }
+        }
+    }
+
+    /**
+     * This Logger call is leaking a WeakReference in Logger.kids
+     */
+    private static void callAnonymousLogger() {
+        for (int i = 0; i < INSTANCE_COUNT; i++) {
+            java.util.logging.Logger.getAnonymousLogger();
+        }
+    }
+
+    /**
+     * 'vm.heapHisto("-live")' will request a full GC
+     */
+    private static int getInstanceCountFromHeapHisto() throws AttachNotSupportedException, Exception {
+        int instanceCount = 0;
+
+        HotSpotVirtualMachine vm = (HotSpotVirtualMachine) VirtualMachine
+                .attach(Long.toString(ProcessTools.getProcessId()));
+        try {
+            try (InputStream heapHistoStream = vm.heapHisto("-live");
+                    BufferedReader in = new BufferedReader(new InputStreamReader(heapHistoStream))) {
+                String inputLine;
+                while ((inputLine = in.readLine()) != null) {
+                    if (inputLine.contains(TARGET_CLASS)) {
+                        instanceCount = Integer.parseInt(inputLine
+                                .split("[ ]+")[2]);
+                        System.out.println("instance count: " + instanceCount);
+                        break;
+                    }
+                }
+            }
+        } finally {
+            vm.detach();
+        }
+
+        assertGreaterThan(instanceCount, 0, "No instances of " + TARGET_CLASS + " are found");
+
+        return instanceCount;
+    }
+
+    /**
+     * Delay for 1/10 of a second to avoid CPU saturation
+     */
+    private static void delayExecution() {
+        try {
+            Thread.sleep(100);
+        } catch (InterruptedException ie) {
+            // Ignore any exceptions
+        }
+    }
+
+}