8197595: Serialization javadoc should link to security best practices

Reviewed-by: lancea, mullan, ahgross

src/java.base/share/classes/java/io/ObjectInputFilter.java

@@ -38,6 +38,15 @@ import jdk.internal.misc.SharedSecrets;
 
 /**
  * Filter classes, array lengths, and graph metrics during deserialization.
+ *
+ * <p><strong>Warning: Deserialization of untrusted data is inherently dangerous
+ * and should be avoided. Untrusted data should be carefully validated according to the
+ * "Serialization and Deserialization" section of the
+ * {@extLink secure_coding_guidelines_javase Secure Coding Guidelines for Java SE}.
+ * {@extLink serialization_filter_guide Serialization Filtering} describes best
+ * practices for defensive use of serial filters.
+ * </strong></p>
+ *
  * If set on an {@link ObjectInputStream}, the {@link #checkInput checkInput(FilterInfo)}
  * method is called to validate classes, the length of each array,
  * the number of objects being read from the stream, the depth of the graph,

src/java.base/share/classes/java/io/ObjectInputStream.java

@@ -52,6 +52,14 @@ import sun.reflect.misc.ReflectUtil;
  * An ObjectInputStream deserializes primitive data and objects previously
  * written using an ObjectOutputStream.
  *
+ * <p><strong>Warning: Deserialization of untrusted data is inherently dangerous
+ * and should be avoided. Untrusted data should be carefully validated according to the
+ * "Serialization and Deserialization" section of the
+ * {@extLink secure_coding_guidelines_javase Secure Coding Guidelines for Java SE}.
+ * {@extLink serialization_filter_guide Serialization Filtering} describes best
+ * practices for defensive use of serial filters.
+ * </strong></p>
+ *
  * <p>ObjectOutputStream and ObjectInputStream can provide an application with
  * persistent storage for graphs of objects when used with a FileOutputStream
  * and FileInputStream respectively.  ObjectInputStream is used to recover

src/java.base/share/classes/java/io/Serializable.java

@@ -27,7 +27,17 @@ package java.io;
 
 /**
  * Serializability of a class is enabled by the class implementing the
- * java.io.Serializable interface. Classes that do not implement this
+ * java.io.Serializable interface.
+ *
+ * <p><strong>Warning: Deserialization of untrusted data is inherently dangerous
+ * and should be avoided. Untrusted data should be carefully validated according to the
+ * "Serialization and Deserialization" section of the
+ * {@extLink secure_coding_guidelines_javase Secure Coding Guidelines for Java SE}.
+ * {@extLink serialization_filter_guide Serialization Filtering} describes best
+ * practices for defensive use of serial filters.
+ * </strong></p>
+ *
+ * Classes that do not implement this
  * interface will not have any of their state serialized or
  * deserialized.  All subtypes of a serializable class are themselves
  * serializable.  The serialization interface has no methods or fields

src/java.base/share/classes/java/io/package-info.java

@@ -31,19 +31,17 @@
  * method in any class or interface in this package will cause a
  * {@code NullPointerException} to be thrown.
  *
- * <h2>Package Specification</h2>
+ * <h2>Object Serialization</h2>
+ * <p><strong>Warning: Deserialization of untrusted data is inherently dangerous
+ * and should be avoided. Untrusted data should be carefully validated according to the
+ * "Serialization and Deserialization" section of the
+ * {@extLink secure_coding_guidelines_javase Secure Coding Guidelines for Java SE}.
+ * </strong></p>
  * <ul>
  *   <li><a href="{@docRoot}/../specs/serialization/index.html">
  *       Java Object Serialization Specification </a>
- * </ul>
- *
- * <h2>Related Documentation</h2>
- *
- * For overviews, tutorials, examples, guides, and tool documentation,
- * please see:
- * <ul>
- *     <li>{@extLink serialver_tool_reference The serialver tool}</li>
- *     <li>{@extLink serialization_guide Serialization Documentation}</li>
+ *   <li>{@extLink serialization_filter_guide Serial Filtering} best practices</li>
+ *   <li>{@extLink serialver_tool_reference The serialver tool}</li>
  * </ul>
  *
  * @since 1.0