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.
2026-03-26 17:11:57 -04:00 · 2026-03-26 17:11:57 -04:00 · 0a580b313d
commit 0a580b313d
70422 changed files with 17213626 additions and 0 deletions
--- a/test/jdk/java/security/Security/ClassLoaderDeadlock/ClassLoaderDeadlock.java
+++ b/test/jdk/java/security/Security/ClassLoaderDeadlock/ClassLoaderDeadlock.java
@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2004, 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 5094825
+* @summary verify no deadlock if crypto provider in other classloader is used to verify signed jars
+* @library ./Deadlock.jar
+* @compile provider/HashProvider.java
+* @run main/othervm/timeout=30 ClassLoaderDeadlock
+*/
+
+import java.net.*;
+
+import java.security.*;
+
+public class ClassLoaderDeadlock {
+
+    public static void main(String[] args) throws Exception {
+        // create a new classloader
+        URL url = new URL("file:provider/");
+        final DelayClassLoader cl = new DelayClassLoader(url);
+
+        // install a provider on the custom class loader as the most prefered provider
+        Class clazz = cl.loadClass("HashProvider");
+        Provider p = (Provider)clazz.newInstance();
+        Security.insertProviderAt(p, 1);
+
+        // add a delay in class loading for reproducability
+        cl.delay = 1000;
+
+        new Thread() {
+            public void run() {
+                try {
+                    // load a random system class
+                    // this locks the DelayClassLoader and after the delay the system class loader
+                    Class c1 = cl.loadClass("java.lang.String");
+                    System.out.println(c1);
+                } catch (Exception e) {
+                    e.printStackTrace();
+                }
+            }
+        }.start();
+
+        // make sure the other thread got a chance to run and grab the lock
+        Thread.sleep(200);
+
+        // load a random class from a signed JAR file to trigger JAR signature verification
+        // locks system class loader first and then tries to lock DelayClassLoader to load the hashes
+        // DEADLOCK HAPPENS HERE
+        Class c2 = Class.forName("com.abc.Tst1");
+
+        // NOT REACHED
+        System.out.println(c2);
+
+        System.out.println("OK");
+    }
+
+    static class DelayClassLoader extends URLClassLoader {
+
+        volatile int delay;
+
+        DelayClassLoader(URL url) {
+            super(new URL[] {url});
+        }
+
+        protected synchronized Class loadClass(String name, boolean resolve) throws ClassNotFoundException {
+            System.out.println("-loadClass(" + name + "," + resolve + ")");
+            try {
+                // delay so that we hold the lock for a longer period
+                // makes it much easier to reproduce
+                Thread.sleep(delay);
+            } catch (InterruptedException e) { e.printStackTrace(); }
+            return super.loadClass(name, resolve);
+        }
+    }
+
+}