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/AccessibleObject/CanAccessTest.java

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+/*
+ * Copyright (c) 2017, 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.
+ */
+
+/*
+ * @test
+ * @build CanAccessTest
+ * @modules java.base/jdk.internal.misc:+open
+ * @run junit/othervm CanAccessTest
+ * @summary Test AccessibleObject::canAccess method
+ */
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Method;
+import java.security.SecureClassLoader;
+
+import jdk.internal.misc.Unsafe;
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
+
+public class CanAccessTest {
+    private static Unsafe INSTANCE = Unsafe.getUnsafe();
+
+    /**
+     * null object parameter for Constructor
+     */
+    @Test
+    public void testConstructor() throws Exception {
+        Constructor<?> ctor = Unsafe.class.getDeclaredConstructor();
+        assertFalse(ctor.canAccess(null));
+        assertTrue(ctor.trySetAccessible());
+
+        // non-null object parameter
+        assertThrows(IllegalArgumentException.class, () -> ctor.canAccess(INSTANCE));
+    }
+
+    /**
+     * Test protected constructors
+     */
+    @Test
+    public void testProtectedConstructor() throws Exception {
+        TestLoader.testProtectedConstructorNonOpenedPackage();
+
+        Constructor<?> ctor = TestLoader.class.getDeclaredConstructor();
+        assertTrue(ctor.canAccess(null));
+    }
+
+    /**
+     * null object parameter  for static members
+     */
+    @Test
+    public void testStaticMember() throws Exception {
+        Method m = Unsafe.class.getDeclaredMethod("throwIllegalAccessError");
+        assertFalse(m.canAccess(null));
+        assertTrue(m.trySetAccessible());
+
+        // non-null object parameter
+        assertThrows(IllegalArgumentException.class, () -> m.canAccess(INSTANCE));
+    }
+
+    /**
+     * Test protected static
+     */
+    @Test
+    public void testProtectedStatic() throws Exception {
+        Method m = TestLoader.testProtectedStatic();
+        assertFalse(m.canAccess(null));
+    }
+
+    /**
+     * the specified object must be an instance of the declaring class
+     * for instance members
+     */
+    @Test
+    public void testInstanceMethod() throws Exception {
+        Method m = Unsafe.class.getDeclaredMethod("allocateMemory0", long.class);
+        assertFalse(m.canAccess(INSTANCE));
+
+        assertThrows(IllegalArgumentException.class, () -> m.canAccess(null));
+    }
+
+    /**
+     * the specified object must be an instance of the declaring class
+     * for instance members
+     */
+    @Test
+    public void testInvalidInstanceObject() throws Exception {
+        Class<?> clazz = Class.forName("sun.security.x509.X500Name");
+        Method m = clazz.getDeclaredMethod("size");
+
+        assertThrows(IllegalArgumentException.class, () -> m.canAccess(INSTANCE));
+    }
+
+
+    static class TestLoader extends SecureClassLoader {
+        public static Method testProtectedStatic() throws Exception {
+            Method m = ClassLoader.class.getDeclaredMethod("registerAsParallelCapable");
+            assertTrue(m.canAccess(null));
+            return m;
+        }
+
+        protected TestLoader() throws Exception {
+            Constructor<?> ctor = SecureClassLoader.class.getDeclaredConstructor();
+            assertFalse(ctor.canAccess(null));
+            assertFalse(ctor.trySetAccessible());
+        }
+
+        public static void testProtectedConstructorNonOpenedPackage() throws Exception {
+            new TestLoader();
+        }
+    }
+}