RELEASE NOTES: JDK 8u162

Decode error with Tomcat version 7.x

The zlib version shipped in the 8u151, 7u161 JDK releases was updated to zlib v1.2.11. The deflate functionality in this version causes a compatibility issue with Tomcat v7.x. Server responses can appear as corrupt or can fail to be decoded. The issue is seen if Tomcat is using compression (e.g. compression="on" in server.xml). This issue is being fixed via JDK-8189789 [https://bugs.openjdk.java.net/browse/JDK-8189789].

Users could disable the compression mode on their Tomcat servers as a workaround. Tomcat versions 8.x and later don't appear to be affected.

TLS Session Hash and Extended Master Secret Extension Support

Support has been added for the TLS session hash and extended master secret extension (RFC 7627) in JDK JSSE provider. Note that in general, a server certificate change is restricted if endpoint identification is not enabled and the previous handshake is a session-resumption abbreviated initial handshake, unless the identities represented by both certificates can be regarded as the same. However, if the extension is enabled or negotiated, the server certificate changing restriction is not necessary and will be discarded accordingly. In case of compatibility issues, an application may disable negotiation of this extension by setting the System Property jdk.tls.useExtendedMasterSecret to false in the JDK. By setting the System Property jdk.tls.allowLegacyResumption to false, an application can reject abbreviated handshaking when the session hash and extended master secret extension are not negotiated. By setting the System Property jdk.tls.allowLegacyMasterSecret to false, an application can reject connections that do not support the session hash and extended master secret extension.

Disable exportable cipher suites

To improve the strength of SSL/TLS connections, exportable cipher suites have been disabled in SSL/TLS connections in the JDK by the jdk.tls.disabledAlgorithms Security Property.

JVM Crash during G1 GC

A klass that has been considered unreachable by the concurrent marking of G1, can be looked up in the ClassLoaderData/SystemDictionary, and its _java_mirror or _class_loader fields can be stored in a root or any other reachable object making it alive again. Whenever a klass is resurrected in this manner, the SATB part of G1 needs to be notified about this, otherwise, the concurrent marking remark phase will erroneously unload that klass.

In this particular crash, while G1 was doing concurrent marking and had prepared its list of unreachable classes, JVMTI on a Java thread could traverse classes in the CLD and store thread-local JNIHandles for the java_mirror of the loaded classes. G1 did not have knowledge of these thread-local JNIHandles, and in the remark phase, it unloaded classes per its prior knowledge of unreachable classes. When these JNIHandles were later scanned, it lead to a crash.

This fix for JDK-8187577 informs G1's SATB that a klass has been resurrected and should not be unloaded.