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/hotspot/jtreg/runtime/ClassUnload/MyDiffClassLoader.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2018, 2021, 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.io.*;
+import jdk.test.lib.compiler.InMemoryJavaCompiler;
+import jdk.test.lib.classloader.ClassUnloadCommon;
+
+public class MyDiffClassLoader extends ClassLoader {
+
+    public String loaderName;
+    public static boolean switchClassData = false;
+
+    MyDiffClassLoader(String name) {
+        this.loaderName = name;
+    }
+
+    public Class loadClass(String name) throws ClassNotFoundException {
+        if (!name.contains("c1r") &&
+            !name.contains("c1c") &&
+            !name.contains("c1s") &&
+            !name.equals("p2.c2")) {
+                return super.loadClass(name);
+        }
+
+        // new loader loads p2.c2
+        if  (name.equals("p2.c2") && !loaderName.equals("C2Loader")) {
+            Class<?> c = new MyDiffClassLoader("C2Loader").loadClass(name);
+            switchClassData = true;
+            return c;
+        }
+
+        byte[] data = switchClassData ? getNewClassData(name) : ClassUnloadCommon.getClassData(name);
+        System.out.println("name is " + name);
+        return defineClass(name, data, 0, data.length);
+    }
+
+    // Return p2.c2 with everything removed
+    byte[] getNewClassData(String name) {
+        return InMemoryJavaCompiler.compile("p2.c2", "package p2; public class c2 { }");
+    }
+}