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/file/Files/CopyProcFile.java

@@ -0,0 +1,180 @@
+/*
+ * Copyright (c) 2022, 2026, 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.
+ */
+
+import java.io.IOException;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.UncheckedIOException;
+import java.nio.channels.FileChannel;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.ToLongBiFunction;
+import java.util.stream.Stream;
+import static java.nio.file.StandardOpenOption.*;
+
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/*
+ * @test
+ * @bug 8293502
+ * @requires (os.family == "linux")
+ * @summary Ensure that copying from a file in /proc works
+ * @run junit/othervm CopyProcFile
+ */
+public class CopyProcFile {
+    static final String SOURCE = "/proc/version";
+    static final String BUFFERED_COPY = "bufferedCopy";
+    static final String TARGET = "target";
+
+    static final int BUF_SIZE = 8192;
+
+    static long theSize;
+
+    // copy src to dst via Java buffers
+    static long bufferedCopy(String src, String dst) throws IOException {
+        try (InputStream in = new FileInputStream(src);
+             OutputStream out = new FileOutputStream(dst)) {
+            byte[] b = new byte[BUF_SIZE];
+            long total = 0;
+            int n;
+            while ((n = in.read(b)) > 0) {
+                out.write(b, 0, n);
+                total += n;
+            }
+            return total;
+        }
+    }
+
+    // copy src to dst using Files::copy
+    static long copy(String src, String dst) {
+        try {
+            Path target = Files.copy(Path.of(src), Path.of(dst));
+            return Files.size(target);
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+    }
+
+    // copy src to dst using InputStream::transferTo
+    static long transferToIO(String src, String dst) {
+        try (InputStream in = new FileInputStream(src);
+             OutputStream out = new FileOutputStream(dst)) {
+            return in.transferTo(out);
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+    }
+
+    // copy src to dst using FileChannel::transferTo
+    static long transferToNIO(String src, String dst) {
+        try (FileChannel fci = FileChannel.open(Path.of(src), READ);
+             FileChannel fco = FileChannel.open(Path.of(dst), CREATE_NEW, WRITE);) {
+            return fci.transferTo(0, Long.MAX_VALUE, fco);
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+    }
+
+    // copy src to dst using FileChannel::transferFrom
+    static long transferFrom(String src, String dst) {
+        try (FileChannel fci = FileChannel.open(Path.of(src), READ);
+             FileChannel fco = FileChannel.open(Path.of(dst), CREATE_NEW, WRITE);) {
+            return fco.transferFrom(fci, 0, Long.MAX_VALUE);
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+    }
+
+    @BeforeAll
+    public static void createBufferedCopy() throws IOException {
+        System.out.printf("Using source file \"%s\"%n", SOURCE);
+        try {
+            theSize = bufferedCopy(SOURCE, BUFFERED_COPY);
+            System.out.printf("Copied %d bytes from %s%n", theSize, SOURCE);
+        } catch (IOException e) {
+            try {
+                Files.delete(Path.of(BUFFERED_COPY));
+            } catch (IOException ignore) {}
+            throw e;
+        }
+        if (Files.mismatch(Path.of(BUFFERED_COPY), Path.of(SOURCE)) != -1) {
+            throw new RuntimeException("Copy does not match source");
+        }
+    }
+
+    @AfterAll
+    public static void deleteBufferedCopy() {
+        try {
+            Files.delete(Path.of(BUFFERED_COPY));
+        } catch (IOException ignore) {}
+    }
+
+    static class FHolder {
+        ToLongBiFunction<String,String> f;
+
+        FHolder(ToLongBiFunction<String,String> f) {
+            this.f = f;
+        }
+
+        long apply(String src, String dst) {
+            return f.applyAsLong(src, dst);
+        }
+    }
+
+    static Stream<FHolder> functions() throws IOException {
+        return Stream.of
+            (new FHolder((s, d) -> copy(s, d)),
+             new FHolder((s, d) -> transferToIO(s, d)),
+             new FHolder((s, d) -> transferToNIO(s, d)),
+             new FHolder((s, d) -> transferFrom(s, d)));
+    }
+
+    @ParameterizedTest
+    @MethodSource("functions")
+    public void testCopyAndTransfer(FHolder f) throws IOException {
+        try {
+            long size = f.apply(SOURCE, TARGET);
+            if (size != theSize) {
+                throw new RuntimeException("Size: expected " + theSize +
+                                           "; actual: " + size);
+            }
+            long mismatch = Files.mismatch(Path.of(BUFFERED_COPY),
+                                           Path.of(TARGET));
+            assertEquals(-1, mismatch, "Target does not match copy");
+        } finally {
+            try {
+                Files.delete(Path.of(TARGET));
+            } catch (IOException ignore) {}
+        }
+    }
+}