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/nio/channels/FileChannel/ExpandingMap.java
+++ b/test/jdk/java/nio/channels/FileChannel/ExpandingMap.java
@ -0,0 +1,123 @@
+/*
+ * Copyright (c) 2007, 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 4938372 6541641
+ * @summary Flushing dirty pages prior to unmap can cause Cleaner thread to
+ *          abort VM if memory system has pages locked
+ * @run main/othervm ExpandingMap
+ */
+import java.io.File;
+import java.io.RandomAccessFile;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+import java.util.ArrayList;
+
+/**
+ * Test case provided by submitter of 4938372.
+ */
+
+public class ExpandingMap {
+
+    public static void main(String[] args) throws Exception {
+
+        int initialSize = 20480*1024;
+        int maximumMapSize = 16*1024*1024;
+        int maximumFileSize = 300000000;
+
+        File file = File.createTempFile("exp", "tmp");
+        file.deleteOnExit();
+        RandomAccessFile f = new RandomAccessFile(file, "rw");
+        f.setLength(initialSize);
+
+        FileChannel fc = f.getChannel();
+
+        ByteBuffer[] buffers = new ByteBuffer[128];
+
+        System.out.format("map %d -> %d\n", 0, initialSize);
+        buffers[0] = fc.map(FileChannel.MapMode.READ_WRITE, 0, initialSize);
+
+        int currentBuffer = 0;
+        int currentSize = initialSize;
+        int currentPosition = 0;
+
+        ArrayList<String> junk = new ArrayList<String>();
+
+        while (currentPosition+currentSize < maximumFileSize) {
+            int inc = Math.max(1000*1024, (currentPosition+currentSize)/8);
+
+            int size = currentPosition+currentSize+inc;
+            f.setLength(size);
+
+            while (currentSize+inc > maximumMapSize) {
+                if (currentSize < maximumMapSize) {
+                    System.out.format("map %d -> %d\n", currentPosition,
+                        (currentPosition + maximumMapSize));
+                    buffers[currentBuffer] = fc.map(FileChannel.MapMode.READ_WRITE,
+                        currentPosition, maximumMapSize);
+                    fillBuffer(buffers[currentBuffer], currentSize);
+                }
+                currentPosition += maximumMapSize;
+                inc = currentSize+inc-maximumMapSize;
+                currentSize = 0;
+                currentBuffer++;
+                if (currentBuffer == buffers.length) {
+                    ByteBuffer[] old = buffers;
+                    buffers = new ByteBuffer[currentBuffer+currentBuffer/2];
+                    System.arraycopy(old, 0, buffers, 0, currentBuffer);                                        }
+            }
+            currentSize += inc;
+            if (currentSize > 0) {
+                System.out.format("map %d -> %d\n", currentPosition,
+                    (currentPosition + currentSize));
+                buffers[currentBuffer] = fc.map(FileChannel.MapMode.READ_WRITE,
+                     currentPosition, currentSize);
+                fillBuffer(buffers[currentBuffer], currentSize-inc);
+            }
+
+            // busy loop needed to reproduce issue
+            long t = System.currentTimeMillis();
+            while (System.currentTimeMillis() < t+500) {
+                junk.add(String.valueOf(t));
+                if (junk.size() > 100000) junk.clear();
+            }
+        }
+
+        fc.close();
+        // cleanup the ref to mapped buffers so they can be GCed
+        for (int i = 0; i < buffers.length; i++)
+            buffers[i] = null;
+        System.gc();
+        // Take a nap to wait for the Cleaner to cleanup those unrefed maps
+        Thread.sleep(1000);
+        System.out.println("TEST PASSED");
+    }
+
+    static void fillBuffer(ByteBuffer buf, int from) {
+        int limit = buf.limit();
+        for (int i=from; i<limit; i++) {
+            buf.put(i, (byte)i);
+        }
+    }
+}