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/lang/ClassLoader/nativeLibrary/NativeLibraryTest.java

@@ -0,0 +1,136 @@
+/*
+ * Copyright (c) 2017, 2022, 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.
+ */
+
+/*
+ * @test
+ * @bug 8164512 8191360
+ * @requires vm.compMode != "Xcomp"
+ * @comment Under musl, dlclose is a no-op. The static variable 'count' in libnative.c
+ * keeps its value across a GC and the check in Test.java fails.
+ * @requires !vm.musl
+ * @summary verify if the native library is unloaded when the class loader is GC'ed
+ * @library /test/lib/
+ * @build jdk.test.lib.util.ForceGC
+ * @build p.Test
+ * @run main/othervm/native -Xcheck:jni NativeLibraryTest
+ */
+
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+import jdk.test.lib.util.ForceGC;
+
+public class NativeLibraryTest {
+    static final Path CLASSES = Paths.get("classes");
+    static int unloadedCount = 0;
+
+    /*
+     * Called by JNI_OnUnload when the native library is unloaded
+     */
+    static void nativeLibraryUnloaded() {
+        unloadedCount++;
+    }
+
+    public static void main(String... args) throws Exception {
+        setup();
+
+        for (int count=1; count <= 5; count++) {
+            System.out.println("count: " + count);
+            // create a class loader and load a native library
+            runTest();
+            // Unload the class loader and native library, and give the Cleaner
+            // thread a chance to unload the native library.
+            // unloadedCount is incremented when the native library is unloaded.
+            final int finalCount = count;
+            if (!ForceGC.wait(() -> finalCount == unloadedCount)) {
+                throw new RuntimeException("Expected unloaded=" + count +
+                    " but got=" + unloadedCount);
+            }
+        }
+    }
+
+    /*
+     * Loads p.Test class with a new class loader and its static initializer
+     * will load a native library.
+     *
+     * The class loader becomes unreachable when this method returns and
+     * the native library should be unloaded at some point after the class
+     * loader is garbage collected.
+     */
+    static void runTest() throws Exception {
+        // invoke p.Test.run() that loads the native library
+        Runnable r = newTestRunnable();
+        r.run();
+
+        // reload the native library by the same class loader
+        r.run();
+
+        // load the native library by another class loader
+        Runnable r1 = newTestRunnable();
+        try {
+            r1.run();
+            throw new RuntimeException("should fail to load the native library" +
+                    " by another class loader");
+        } catch (UnsatisfiedLinkError e) {}
+    }
+
+    /*
+     * Loads p.Test class with a new class loader and returns
+     * a Runnable instance.
+     */
+    static Runnable newTestRunnable() throws Exception {
+        TestLoader loader = new TestLoader();
+        Class<?> c = Class.forName("p.Test", true, loader);
+        return (Runnable) c.newInstance();
+    }
+
+    static class TestLoader extends URLClassLoader {
+        static URL[] toURLs() {
+            try {
+                return new URL[] { CLASSES.toUri().toURL() };
+            } catch (MalformedURLException e) {
+                throw new Error(e);
+            }
+        }
+
+        TestLoader() {
+            super("testloader", toURLs(), ClassLoader.getSystemClassLoader());
+        }
+    }
+
+    /*
+     * move p/Test.class out from classpath to the scratch directory
+     */
+    static void setup() throws IOException {
+        String dir = System.getProperty("test.classes", ".");
+        Path file = Paths.get("p", "Test.class");
+        Files.createDirectories(CLASSES.resolve("p"));
+        Files.move(Paths.get(dir).resolve(file),
+                   CLASSES.resolve("p").resolve("Test.class"));
+    }
+}