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/reflect/Proxy/nonPublicProxy/DefaultMethodProxy.java

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+/*
+ * Copyright (c) 2020, 2026, 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.lang.reflect.*;
+import java.util.Arrays;
+import java.util.stream.Collectors;
+
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+
+/*
+ * @test
+ * @bug 8159746
+ * @summary Test invoking a default method in a non-public proxy interface
+ * @build p.Foo p.Bar p.ProxyMaker
+ * @run junit DefaultMethodProxy
+ */
+public class DefaultMethodProxy {
+    public interface I {
+        default String m() { return "I"; }
+    }
+
+    @Test
+    public void publicInterface() throws ReflectiveOperationException {
+        // create a proxy instance of a public proxy interface should succeed
+        Proxy proxy = (Proxy)Proxy.newProxyInstance(DefaultMethodProxy.class.getClassLoader(),
+                new Class<?>[] { I.class }, IH);
+
+        testDefaultMethod(proxy, "I");
+
+        // can get the invocation handler
+        assertSame(IH, Proxy.getInvocationHandler(proxy));
+    }
+
+    private static Object[][] nonPublicIntfs() throws ClassNotFoundException {
+        Class<?> fooClass = Class.forName("p.Foo");
+        Class<?> barClass = Class.forName("p.Bar");
+        return new Object[][]{
+                new Object[]{new Class<?>[]{ fooClass }, "foo"},
+                new Object[]{new Class<?>[]{ barClass, fooClass }, "bar"},
+                new Object[]{new Class<?>[]{ barClass }, "bar"},
+        };
+    }
+
+    @ParameterizedTest
+    @MethodSource("nonPublicIntfs")
+    public void hasPackageAccess(Class<?>[] intfs, String expected) throws ReflectiveOperationException {
+        Proxy proxy = (Proxy)Proxy.newProxyInstance(DefaultMethodProxy.class.getClassLoader(), intfs, IH);
+        testDefaultMethod(proxy, expected);
+
+        // proxy instance is created successfully even invocation handler has no access
+        Proxy.newProxyInstance(DefaultMethodProxy.class.getClassLoader(), intfs, IH_NO_ACCESS);
+    }
+
+    // IAE thrown at invocation time
+    @ParameterizedTest
+    @MethodSource("nonPublicIntfs")
+    public void noPackageAccess(Class<?>[] intfs, String ignored) throws Throwable {
+        Proxy proxy = (Proxy)Proxy.newProxyInstance(DefaultMethodProxy.class.getClassLoader(), intfs, IH_NO_ACCESS);
+        InvocationTargetException ite = assertThrows(InvocationTargetException.class, () -> testDefaultMethod(proxy, "dummy"));
+        var ute = assertInstanceOf(UndeclaredThrowableException.class, ite.getCause(), "unwrap the InvocationTargetException");
+        assertInstanceOf(IllegalAccessException.class, ute.getCause(), "unwrap the UndeclaredThrowableException");
+    }
+
+    /*
+     * Verify if a default method "m" can be invoked successfully
+     */
+    static void testDefaultMethod(Proxy proxy, String expected) throws ReflectiveOperationException {
+        Method m = proxy.getClass().getDeclaredMethod("m");
+        m.setAccessible(true);
+        String name = (String) m.invoke(proxy);
+        if (!expected.equals(name)) {
+            throw new RuntimeException("return value: " + name + " expected: " + expected);
+        }
+    }
+
+    // invocation handler with access to the non-public interface in package p
+    private static final InvocationHandler IH = (proxy, method, params) -> {
+        System.out.format("Proxy for %s: invoking %s%n",
+                Arrays.stream(proxy.getClass().getInterfaces())
+                      .map(Class::getName)
+                      .collect(Collectors.joining(", ")), method.getName());
+        if (method.isDefault()) {
+            return p.ProxyMaker.invoke(proxy, method, params);
+        }
+        throw new UnsupportedOperationException(method.toString());
+    };
+
+    // invocation handler with no access to the non-public interface in package p
+    // expect IllegalAccessException thrown
+    private static final InvocationHandler IH_NO_ACCESS = (proxy, method, params) -> {
+        System.out.format("Proxy for %s: invoking %s%n",
+                Arrays.stream(proxy.getClass().getInterfaces())
+                        .map(Class::getName)
+                        .collect(Collectors.joining(", ")), method.getName());
+        if (method.isDefault()) {
+            InvocationHandler.invokeDefault(proxy, method, params);
+        }
+        throw new UnsupportedOperationException(method.toString());
+    };
+}