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/ParallelLoad/CallLoadClass/ClassLoadingThread.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2022, 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.util.concurrent.Semaphore;
+
+class ClassLoadingThread extends Thread {
+
+    private ClassLoader ldr = null;
+    private int which;
+    private Semaphore syncOrder;
+
+    public ClassLoadingThread(ClassLoader loader, int i, Semaphore sem) {
+        ldr = loader;
+        which = i;
+        syncOrder = sem;
+    }
+
+    private boolean success = true;
+    public boolean report_success() { return success; }
+
+    public void callForName() {
+        try {
+            ThreadPrint.println("Starting forName thread ...");
+            // Initiate class loading using specified type
+            Class<?> a = Class.forName("A", true, ldr);
+            Object obj = a.getConstructor().newInstance();
+        } catch (Throwable e) {
+            ThreadPrint.println("Exception is caught: " + e);
+            e.printStackTrace();
+            success = false;
+        }
+    }
+
+    public void callLoadClass() {
+        try {
+            ThreadPrint.println("Starting loadClass thread ...");
+            Class<?> a = ldr.loadClass("A");
+            Object obj = a.getConstructor().newInstance();
+            success = false; // Should have thrown LinkageError
+        } catch (Throwable e) {
+            // If you call loadClass directly, this will result in LinkageError
+            ThreadPrint.println("Exception is caught: " + e);
+            e.printStackTrace();
+            success = (e instanceof LinkageError);
+        }
+    }
+
+    public void run() {
+       if (which == 0) {
+           callLoadClass();
+       } else {
+           try {
+               syncOrder.acquire();  // wait until loadClass is waiting.
+           } catch (InterruptedException idc) {}
+           callForName();
+       }
+    }
+}