RELEASE NOTES: JDK 21.0.1

Validations on ZIP64 Extra Fields

A (JDK enhancement)[https://bugs.openjdk.org/browse/JDK-8311940] has improved validation of the ZIP64 Extra Fields contained within zip files and jar files. Files which do not satisfy these new validation checks may result in ZipException : Invalid CEN header (invalid zip64 extra data field size).

The following third party tools have released patches to better adhere to the ZIP File Format Specification: - Apache Commons Compress fix for Empty CEN Zip64 Extra Headers fixed in Commons Compress release 1.11 - Apache Ant fix for Empty CEN Zip64 Extra Headers fixed in Ant 1.10.14
- BND issue with writing invalid Extra Headers fixed in BND 5.3 - The maven-bundle-plugin 5.1.5 includes the BND 5.3 patch.

If these improved validation checks cause issues for deployed zip or jar files, check how the file was created and whether patches are available from the generating software to resolve the issue. The new validation checks can be disabled by adding -Djdk.util.zip.disableZip64ExtraFieldValidation=true to the runtime launcher arguments.

Further modification of validations on ZIP64 Extra Fields contained within zip and jar files will be made in the upcoming JDK release. See JDK-8313765.

JVM May Hang When Using Generational ZGC if a VM Handshake Stalls on Memory

The JVM can hang under an uncommon condition that involves the JVM running out of heap memory, the GC just starting a relocation phase to reclaim memory, and a JVM thread-local Handshake asking to relocate an object.

`java.util.regex.MatchResult` Might Throw `StringIndexOutOfBoundsException` on Regex Patterns Containing Lookaheads and Lookbehinds

JDK-8132995 introduced an unintended regression when using instances returned by java.util.regex.Matcher.toMatchResult().

This happens on java.util.regex.Patterns containing lookaheads and lookbehinds that, in turn, contain groups. If these are located outside the match, it results in throwing StringIndexOutOfBoundsException when accessing these groups. See JDK-8312976 for an example.

Increase Default Value of the System Property `jdk.jar.maxSignatureFileSize`

The system property, jdk.jar.maxSignatureFileSize, allows applications to control the maximum size of signature files in a signed JAR. Its default value has been increased from 8000000 bytes (8 MB) to 16000000 bytes (16 MB).

Added Certigna Root CA Certificate

The following root certificate has been added to the cacerts truststore: ` + Certigna (Dhimyotis) + certignarootca DN: CN=Certigna Root CA, OU=0002 48146308100036, O=Dhimyotis, C=FR `