Additional check when unpacking archives. Contributed by Jason Lowe and Akira Ajisaka.

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileUtil.java

@@ -620,16 +620,21 @@ public class FileUtil {
   public static void unZip(File inFile, File unzipDir) throws IOException {
     Enumeration<? extends ZipEntry> entries;
     ZipFile zipFile = new ZipFile(inFile);
+    String targetDirPath = unzipDir.getCanonicalPath() + File.separator;
 
     try {
       entries = zipFile.entries();
       while (entries.hasMoreElements()) {
         ZipEntry entry = entries.nextElement();
         if (!entry.isDirectory()) {
+          File file = new File(unzipDir, entry.getName());
+          if (!file.getCanonicalPath().startsWith(targetDirPath)) {
+            throw new IOException("expanding " + entry.getName()
+                + " would create file outside of " + unzipDir);
+          }
           InputStream in = zipFile.getInputStream(entry);
           try {
-            File file = new File(unzipDir, entry.getName());
+            if (!file.getParentFile().mkdirs()) {
-            if (!file.getParentFile().mkdirs()) {           
               if (!file.getParentFile().isDirectory()) {
                 throw new IOException("Mkdirs failed to create " + 
                                       file.getParentFile().toString());
@@ -738,6 +743,13 @@ public class FileUtil {
   
   private static void unpackEntries(TarArchiveInputStream tis,
       TarArchiveEntry entry, File outputDir) throws IOException {
+    String targetDirPath = outputDir.getCanonicalPath() + File.separator;
+    File outputFile = new File(outputDir, entry.getName());
+    if (!outputFile.getCanonicalPath().startsWith(targetDirPath)) {
+      throw new IOException("expanding " + entry.getName()
+          + " would create entry outside of " + outputDir);
+    }
+
     if (entry.isDirectory()) {
       File subDir = new File(outputDir, entry.getName());
       if (!subDir.mkdirs() && !subDir.isDirectory()) {
@@ -752,7 +764,6 @@ public class FileUtil {
       return;
     }
 
-    File outputFile = new File(outputDir, entry.getName());
     if (!outputFile.getParentFile().exists()) {
       if (!outputFile.getParentFile().mkdirs()) {
         throw new IOException("Mkdirs failed to create tar internal dir "

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestFileUtil.java

@@ -38,6 +38,7 @@ import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.net.UnknownHostException;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -740,10 +741,8 @@ public class TestFileUtil {
   
   @Test (timeout = 30000)
   public void testUnZip() throws IOException {
-    // make sa simple zip
     setupDirs();
-    
+    // make a simple zip
-    // make a simple tar:
     final File simpleZip = new File(del, FILE);
     OutputStream os = new FileOutputStream(simpleZip); 
     ZipOutputStream tos = new ZipOutputStream(os);
@@ -760,7 +759,7 @@ public class TestFileUtil {
       tos.close();
     }
     
-    // successfully untar it into an existing dir:
+    // successfully unzip it into an existing dir:
     FileUtil.unZip(simpleZip, tmp);
     // check result:
     assertTrue(new File(tmp, "foo").exists());
@@ -775,8 +774,36 @@ public class TestFileUtil {
     } catch (IOException ioe) {
       // okay
     }
-  }  
+  }
-  
+
+  @Test (timeout = 30000)
+  public void testUnZip2() throws IOException {
+    setupDirs();
+    // make a simple zip
+    final File simpleZip = new File(del, FILE);
+    OutputStream os = new FileOutputStream(simpleZip);
+    try (ZipOutputStream tos = new ZipOutputStream(os)) {
+      // Add an entry that contains invalid filename
+      ZipEntry ze = new ZipEntry("../foo");
+      byte[] data = "some-content".getBytes(StandardCharsets.UTF_8);
+      ze.setSize(data.length);
+      tos.putNextEntry(ze);
+      tos.write(data);
+      tos.closeEntry();
+      tos.flush();
+      tos.finish();
+    }
+
+    // Unzip it into an existing dir
+    try {
+      FileUtil.unZip(simpleZip, tmp);
+      Assert.fail("unZip should throw IOException.");
+    } catch (IOException e) {
+      GenericTestUtils.assertExceptionContains(
+          "would create file outside of", e);
+    }
+  }
+
   @Test (timeout = 30000)
   /*
    * Test method copy(FileSystem srcFS, Path src, File dst, boolean deleteSource, Configuration conf)