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/invoke/defineHiddenClass/LambdaNestedInnerTest.java

@@ -0,0 +1,148 @@
+/*
+ * Copyright (c) 2019, 2025, 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
+ * @summary define a lambda proxy class whose target class has an invalid
+ *          nest membership
+ * @run junit/othervm p.LambdaNestedInnerTest
+ */
+
+package p;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Arrays;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import static java.nio.file.StandardCopyOption.REPLACE_EXISTING;
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+public class LambdaNestedInnerTest {
+    private static final String INNER_CLASSNAME = "p.LambdaNestedInnerTest$Inner";
+    private static final String DIR = "missingOuter";
+    public static class Inner implements Runnable {
+        // generate lambda proxy class
+        private Runnable lambda1 = this::doit;
+
+        @Override
+        public void run() {
+            // validate the lambda proxy class
+            Class<?> lambdaProxyClass = lambda1.getClass();
+            assertTrue(lambdaProxyClass.isHidden());
+            System.out.format("%s nest host %s nestmate of Inner class %s%n",
+                    lambdaProxyClass, lambdaProxyClass.getNestHost(),
+                    lambdaProxyClass.isNestmateOf(Inner.class));
+            assertTrue(lambdaProxyClass.getNestHost() == Inner.class.getNestHost());
+            assertTrue(Arrays.equals(lambdaProxyClass.getNestMembers(), Inner.class.getNestMembers()));
+            assertTrue(lambdaProxyClass.isNestmateOf(Inner.class));
+            lambda1.run();
+        }
+
+        // junit may not be visible to this class
+        private static void assertTrue(boolean x) {
+            if (!x) {
+                throw new AssertionError("expected true but found false");
+            }
+        }
+
+        private void doit() {
+        }
+    }
+
+    @BeforeAll
+    public static void setup() throws IOException {
+        String filename = INNER_CLASSNAME.replace('.', File.separatorChar) + ".class";
+        Path src = Paths.get(System.getProperty("test.classes"), filename);
+        Path dest = Paths.get(DIR, filename);
+        Files.createDirectories(dest.getParent());
+        Files.copy(src, dest, REPLACE_EXISTING);
+    }
+
+    @Test
+    public void test() throws Exception {
+        Class<?> inner = Class.forName(INNER_CLASSNAME);
+        // inner class is a nest member of LambdaNestedInnerTest
+        Class<?> nestHost = inner.getNestHost();
+        assertSame(LambdaNestedInnerTest.class, nestHost);
+        Set<Class<?>> members = Arrays.stream(nestHost.getNestMembers()).collect(Collectors.toSet());
+        assertEquals(Set.of(nestHost, inner, TestLoader.class), members);
+
+        // spin lambda proxy hidden class
+        Runnable runnable = (Runnable) inner.newInstance();
+        runnable.run();
+    }
+
+    @Test
+    public void nestHostNotExist() throws Exception {
+        URL[] urls = new URL[] { Paths.get(DIR).toUri().toURL() };
+        URLClassLoader loader = new URLClassLoader(urls, null);
+        Class<?> inner = loader.loadClass(INNER_CLASSNAME);
+        assertSame(loader, inner.getClassLoader());
+        assertSame(inner, inner.getNestHost());   // linkage error ignored
+
+        Runnable runnable = (Runnable) inner.newInstance();
+        // this validates the lambda proxy class
+        runnable.run();
+    }
+
+    /*
+     * Tests IncompatibleClassChangeError thrown since the true nest host is not
+     * in the same runtime package as the hidden class
+     */
+    @Test
+    public void nestHostNotSamePackage() throws Exception {
+        URL[] urls = new URL[] { Paths.get(DIR).toUri().toURL() };
+        TestLoader loader = new TestLoader(urls);
+
+        Class<?> inner = loader.loadClass(INNER_CLASSNAME);
+        assertSame(loader, inner.getClassLoader());
+        assertSame(inner, inner.getNestHost());   // linkage error ignored.
+
+        Runnable runnable = (Runnable) inner.newInstance();
+        // this validates the lambda proxy class
+        runnable.run();
+    }
+
+    static class TestLoader extends URLClassLoader {
+        TestLoader(URL[] urls) {
+            super(urls, TestLoader.class.getClassLoader());
+        }
+        public Class<?> loadClass(String name) throws ClassNotFoundException {
+            if (INNER_CLASSNAME.equals(name)) {
+                return findClass(name);
+            } else {
+                // delegate to its parent
+                return loadClass(name, false);
+            }
+        }
+    }
+}