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/nio/channels/FileChannel/ReleaseOnCloseDeadlock.java

@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2009, 2010, 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 6543863 6842687
+ * @summary Try to cause a deadlock between (Asynchronous)FileChannel.close
+ *   and FileLock.release
+ */
+
+import java.io.*;
+import java.nio.file.Path;
+import static java.nio.file.StandardOpenOption.*;
+import java.nio.channels.*;
+import java.util.concurrent.*;
+
+public class ReleaseOnCloseDeadlock {
+    private static final int LOCK_COUNT = 1024;
+
+    public static void main(String[] args) throws IOException {
+        File blah = File.createTempFile("blah", null);
+        blah.deleteOnExit();
+        try {
+            for (int i=0; i<100; i++) {
+                test(blah.toPath());
+            }
+        } finally {
+            blah.delete();
+        }
+    }
+
+    static void test(Path file) throws IOException {
+        FileLock[] locks = new FileLock[LOCK_COUNT];
+
+        FileChannel fc = FileChannel.open(file, READ, WRITE);
+        for (int i=0; i<LOCK_COUNT; i++) {
+            locks[i] = fc.lock(i, 1, true);
+        }
+        tryToDeadlock(fc, locks);
+
+        AsynchronousFileChannel ch = AsynchronousFileChannel.open(file, READ, WRITE);
+        for (int i=0; i<LOCK_COUNT; i++) {
+            try {
+                locks[i] = ch.lock(i, 1, true).get();
+            } catch (InterruptedException x) {
+                throw new RuntimeException(x);
+            } catch (ExecutionException x) {
+                throw new RuntimeException(x);
+            }
+        }
+        tryToDeadlock(ch, locks);
+    }
+
+    static void tryToDeadlock(final Channel channel, FileLock[] locks)
+        throws IOException
+    {
+        // start thread to close the file (and invalidate the locks)
+        Thread closer = new Thread(
+            new Runnable() {
+                public void run() {
+                    try {
+                        channel.close();
+                    } catch (IOException ignore) {
+                        ignore.printStackTrace();
+                    }
+                }});
+        closer.start();
+
+        // release the locks explicitly
+        for (int i=0; i<locks.length; i++) {
+            try {
+                locks[i].release();
+            } catch (ClosedChannelException ignore) { }
+        }
+
+        // we are done when closer has terminated
+        while (closer.isAlive()) {
+            try {
+                closer.join();
+            } catch (InterruptedException ignore) { }
+        }
+    }
+}