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/Class/getEnclosingMethod/BadEnclosingMethodTest.java

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+/*
+ * Copyright (c) 2024, 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
+ * @bug 8350704
+ * @summary Test behaviors with various bad EnclosingMethod attribute
+ * @library /test/lib
+ * @run junit BadEnclosingMethodTest
+ */
+
+import jdk.test.lib.ByteCodeLoader;
+import org.junit.jupiter.api.Test;
+
+import java.lang.classfile.ClassFile;
+import java.lang.classfile.attribute.EnclosingMethodAttribute;
+import java.lang.reflect.GenericSignatureFormatError;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Map;
+import java.util.Optional;
+
+import static java.lang.constant.ConstantDescs.INIT_NAME;
+import static org.junit.jupiter.api.Assertions.*;
+
+class BadEnclosingMethodTest {
+
+    private static Path classPath(String className) {
+        return Path.of(System.getProperty("test.classes"), className + ".class");
+    }
+
+    /**
+     * Loads a test class that is transformed from the Enclosed local class in
+     * the Encloser::work method. This local class has its EnclosingMethod
+     * attribute transformed to the specific name and type, which may be malformed
+     * strings.
+     *
+     * @param name the new enclosing method name, may be malformed
+     * @param type the new enclosing method type, may be malformed
+     * @return the loaded test class, for reflective inspection
+     */
+    private Class<?> loadTestClass(String name, String type) throws Exception {
+        var outerName = "Encloser";
+        var className = outerName + "$1Enclosed";
+
+        var cf = ClassFile.of();
+        var cm = cf.parse(classPath(className));
+
+        var bytes = cf.transformClass(cm, (cb, ce) -> {
+            if (ce instanceof EnclosingMethodAttribute em) {
+                var cp = cb.constantPool();
+                var enclosingMethodName = cp.utf8Entry(name);
+                var enclosingMethodType = cp.utf8Entry(type); // a malformed method type
+                cb.with(EnclosingMethodAttribute.of(em.enclosingClass(), Optional.of(cp.nameAndTypeEntry(
+                        enclosingMethodName, enclosingMethodType
+                ))));
+            } else {
+                cb.with(ce);
+            }
+        });
+
+        var map = Map.of(
+                outerName, Files.readAllBytes(classPath(outerName)),
+                className, bytes
+        );
+
+        return new ByteCodeLoader(map, BadEnclosingMethodTest.class.getClassLoader())
+                .loadClass(className);
+    }
+
+    /**
+     * Test reflection behaviors when the EnclosingMethod attribute's type is
+     * an invalid string.
+     */
+    @Test
+    void testMalformedTypes() throws Exception {
+        assertThrowsExactly(ClassFormatError.class, () -> loadTestClass("methodName", "(L[;)V"));
+        assertThrowsExactly(ClassFormatError.class, () -> loadTestClass(INIT_NAME, "(L[;)V"));
+        assertThrowsExactly(ClassFormatError.class, () -> loadTestClass(INIT_NAME, "(Lmissing/;)V"));
+        assertThrowsExactly(ClassFormatError.class, () -> loadTestClass(INIT_NAME, "()L/Missing;"));
+        // only throw if the query type match the method/constructor type
+        assertDoesNotThrow(() -> loadTestClass(INIT_NAME, "Ljava/lang/Object;").getEnclosingMethod());
+        assertDoesNotThrow(() -> loadTestClass("method", "[I").getEnclosingConstructor());
+        // We have to manually intercept field-typed "methods"
+        assertThrows(GenericSignatureFormatError.class, () -> loadTestClass(INIT_NAME, "Ljava/lang/Object;").getEnclosingConstructor());
+        assertThrows(GenericSignatureFormatError.class, () -> loadTestClass("method", "[I").getEnclosingMethod());
+    }
+
+    /**
+     * Test reflective behaviors when the EnclosingMethod attribute's type is
+     * valid, but refers to a class or interface that cannot be found.
+     */
+    @Test
+    void testAbsentMethods() throws Exception {
+        var absentMethodType = loadTestClass("methodName", "(Ldoes/not/Exist;)V");
+        var ex = assertThrows(TypeNotPresentException.class,
+                absentMethodType::getEnclosingMethod);
+        assertEquals("does.not.Exist", ex.typeName());
+
+        var absentConstructorType = loadTestClass(INIT_NAME, "(Ldoes/not/Exist;)V");
+        ex = assertThrows(TypeNotPresentException.class,
+                absentConstructorType::getEnclosingConstructor);
+        assertEquals("does.not.Exist", ex.typeName());
+    }
+}
+
+class Encloser {
+    private static void work() {
+        class Enclosed {
+        }
+    }
+}