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/NoStringToLower.java
+++ b/test/langtools/tools/javac/NoStringToLower.java
@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2013, 2024, 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 8029800
+ * @summary String.toLowerCase()/toUpperCase is generally dangerous, check it is not used in langtools
+ */
+
+import java.io.*;
+import java.util.*;
+import javax.tools.*;
+import java.lang.classfile.*;
+import java.lang.classfile.constantpool.*;
+
+public class NoStringToLower {
+    public static void main(String... args) throws Exception {
+        NoStringToLower c = new NoStringToLower();
+        if (c.run(args))
+            return;
+
+        if (is_jtreg())
+            throw new Exception(c.errors + " errors occurred");
+        else
+            System.exit(1);
+    }
+
+    static boolean is_jtreg() {
+        return (System.getProperty("test.src") != null);
+    }
+
+    /**
+     * Main entry point.
+     */
+    boolean run(String... args) throws Exception {
+        JavaCompiler c = ToolProvider.getSystemJavaCompiler();
+        try (JavaFileManager fm = c.getStandardFileManager(null, null, null)) {
+            JavaFileManager.Location javacLoc = findJavacLocation(fm);
+            String[] pkgs = {
+                "javax.annotation.processing",
+                "javax.lang.model",
+                "javax.tools",
+                "com.sun.source",
+                "java.lang.classfile",
+                "jdk.internal.classfile",
+                "com.sun.tools.doclint",
+                "com.sun.tools.javac",
+                "com.sun.tools.javah",
+                "com.sun.tools.javap",
+                "com.sun.tools.jdeps",
+                "jdk.javadoc"
+            };
+            for (String pkg: pkgs) {
+                for (JavaFileObject fo: fm.list(javacLoc,
+                        pkg, EnumSet.of(JavaFileObject.Kind.CLASS), true)) {
+                    scan(fo);
+                }
+            }
+
+            return (errors == 0);
+        }
+    }
+
+    // depending on how the test is run, javac may be on bootclasspath or classpath
+    JavaFileManager.Location findJavacLocation(JavaFileManager fm) {
+        JavaFileManager.Location[] locns =
+            { StandardLocation.PLATFORM_CLASS_PATH, StandardLocation.CLASS_PATH };
+        try {
+            for (JavaFileManager.Location l: locns) {
+                JavaFileObject fo = fm.getJavaFileForInput(l,
+                    "com.sun.tools.javac.Main", JavaFileObject.Kind.CLASS);
+                if (fo != null)
+                    return l;
+            }
+        } catch (IOException e) {
+            throw new Error(e);
+        }
+        throw new IllegalStateException("Cannot find javac");
+    }
+
+    /**
+     * Verify there are no references to String.toLowerCase() in a class file.
+     */
+    void scan(JavaFileObject fo) throws IOException {
+        try (InputStream in = fo.openInputStream()) {
+            ClassModel cf = ClassFile.of().parse(in.readAllBytes());
+            for (PoolEntry pe : cf.constantPool()) {
+                if (pe instanceof MethodRefEntry ref) {
+                    String methodDesc = ref.owner().name().stringValue() + "." + ref.name().stringValue() + ":" + ref.type().stringValue();
+
+                    if ("java/lang/String.toLowerCase:()Ljava/lang/String;".equals(methodDesc)) {
+                        error("found reference to String.toLowerCase() in: " + fo.getName());
+                    }
+                    if ("java/lang/String.toUpperCase:()Ljava/lang/String;".equals(methodDesc)) {
+                        error("found reference to String.toLowerCase() in: " + fo.getName());
+                    }
+                }
+            }
+        } catch (ConstantPoolException ignore) {
+        }
+    }
+
+    /**
+     * Report an error.
+     */
+    void error(String msg) {
+        System.err.println("Error: " + msg);
+        errors++;
+    }
+
+    int errors;
+}