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/langtools/tools/javac/classreader/TruncatedClassFileTest.java
+++ b/test/langtools/tools/javac/classreader/TruncatedClassFileTest.java
@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2023, 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 8302514
+ * @summary Verify truncated class files are detected and reported as truncated
+ */
+
+import com.sun.tools.javac.Main;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.PrintStream;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.nio.file.Files;
+
+public class TruncatedClassFileTest {
+
+    // We want a bunch of stuff in this file to make the classfile complicated
+    private static final String A_SOURCE = """
+        public class ClassA {
+            public static final boolean z = true;
+            public static final byte b = 7;
+            public static final char c = '*';
+            public static final short s = -12;
+            public static final int i = 123;
+            public static final float f = 123f;
+            public static final long j = 0x1234567812345678L;
+            public static final double d = Math.PI;
+            public static final String str = new String("test123");
+            @SuppressWarnings("blah")
+            public ClassA() {
+                new Thread();
+            }
+        }
+    """;
+
+    // This file will get compiled against a trunctated version of A.class
+    private static final String B_SOURCE = """
+        public class ClassB {
+            public ClassB() {
+                new ClassA();
+            }
+        }
+    """;
+
+    private static final File A_SOURCE_FILE = new File("ClassA.java");
+    private static final File B_SOURCE_FILE = new File("ClassB.java");
+    private static final File A_CLASS_FILE = new File("ClassA.class");
+
+    private static void createSourceFile(File file, String content) throws IOException {
+        try (PrintStream output = new PrintStream(new FileOutputStream(file))) {
+            output.println(content);
+        }
+    }
+
+    public static void main(String... args) throws Exception {
+
+        // Create A.java and B.java
+        createSourceFile(A_SOURCE_FILE, A_SOURCE);
+        createSourceFile(B_SOURCE_FILE, B_SOURCE);
+
+        // Compile A.java
+        createSourceFile(A_SOURCE_FILE, A_SOURCE);
+        int ret = Main.compile(new String[] { A_SOURCE_FILE.toString() });
+        if (ret != 0)
+            throw new AssertionError("compilation of " + A_SOURCE_FILE + " failed");
+        A_SOURCE_FILE.delete();
+
+        // Read A.class
+        final byte[] classfile = Files.readAllBytes(A_CLASS_FILE.toPath());
+
+        // Now compile B.java with truncated versions of A.class
+        for (int length = 0; length < classfile.length; length++) {
+
+            // Write out truncated class file A.class
+            try (FileOutputStream output = new FileOutputStream(A_CLASS_FILE)) {
+                output.write(classfile, 0, length);
+            }
+
+            // Try to compile file B.java
+            final StringWriter diags = new StringWriter();
+            final String[] params = new String[] {
+                "-classpath",
+                ".",
+                "-XDrawDiagnostics",
+                B_SOURCE_FILE.toString()
+            };
+            ret = Main.compile(params, new PrintWriter(diags, true));
+            if (ret == 0)
+                throw new AssertionError("compilation with truncated class file (" + length + ") succeeded?");
+            final String errmsg = "compiler.misc.bad.class.truncated.at.offset: " + length;
+            if (!diags.toString().contains(errmsg))
+                throw new AssertionError("error message not found for truncated class file (" + length + "): " + diags);
+        }
+    }
+}