8238842: AIOOBE in GIFImageReader.initializeStringTable

Reviewed-by: serb, bpb

src/share/classes/com/sun/imageio/plugins/gif/GIFImageReader.java

@@ -911,6 +911,10 @@ public class GIFImageReader extends ImageReader {
         try {
             // Read and decode the image data, fill in theImage
             this.initCodeSize = stream.readUnsignedByte();
+            // GIF allows max 8 bpp, so anything larger is bogus for the roots.
+            if (this.initCodeSize < 1 || this.initCodeSize > 8) {
+                throw new IIOException("Bad code size:" + this.initCodeSize);
+            }
 
             // Read first data block
             this.blockLength = stream.readUnsignedByte();
@@ -1009,7 +1013,6 @@ public class GIFImageReader extends ImageReader {
             processReadAborted();
             return theImage;
         } catch (IOException e) {
-            e.printStackTrace();
             throw new IIOException("I/O error reading image!", e);
         }
     }

test/javax/imageio/plugins/gif/GIFCodeSizeTest.java

+/*
+ * Copyright (c) 2020, 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 8238842
+ * @summary Test incorrect code size results in IOException
+ */
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import javax.imageio.ImageIO;
+
+public class GIFCodeSizeTest {
+
+    static final byte[] DATA =  {
+        (byte)0x47, (byte)0x49, (byte)0x46, (byte)0x38, (byte)0x37,
+        (byte)0x61, (byte)0x02, (byte)0x00, (byte)0x02, (byte)0x00,
+        (byte)0x80, (byte)0x00, (byte)0x80, (byte)0x00, (byte)0xff,
+        (byte)0xff, (byte)0x00, (byte)0x00, (byte)0x00, (byte)0x2c,
+        (byte)0x00, (byte)0x00, (byte)0x01, (byte)0x00, (byte)0x02,
+        (byte)0x00, (byte)0x02, (byte)0x00, (byte)0x00, (byte)0x12,
+        (byte)0x02, (byte)0x84, (byte)0x51, (byte)0x00, (byte)0x3b
+    };
+
+    public static void main(String[] args) /*throws Exception */{
+        try {
+            ImageIO.read(new ByteArrayInputStream(DATA));
+        } catch (IOException e) {
+        }
+    }
+}