Linux kernel 4.15
Ubuntu 18.04 ships with a v4.15 based Linux kernel enabling the latest hardware and peripherals from IBM, Intel, and others. The 18.04 kernel delivers new features inherited from upstream, including:
- CPU controller for the cgroup v2 interface
- AMD secure memory encryption support
- The latest MD driver with software RAID enhancements
- Improved power management for systems with SATA Link Power Management
We also see notable Ubuntu specific achievements with:
- Linux security module stacking support
- Support for signing or POWER host and NV kernels
- Backport improved support for IBM and Intel hardware from Linux 4.16
As of 18.04 release, OpenJDK 10 is the default JRE / JDK. Once OpenJDK 11 reaches GA in September 2018, it will become the default in 18.04.
OpenJDK 8 has moved to the universe and will be available for the life of 18.04. can not be built with OpenJDK 10 or 11. OpenJDK 8 will be updated in 18.04 until Ubuntu 16.04 LTS reaches EOL in April 2021.
In Ubuntu 18.04 LTS, gcc is now set to default to compile applications as position independent executables (PIE) as well as with immediate binding, to make more effective use of Address Space Layout Randomization (ASLR). All packages in main have been rebuilt to take advantage of this, with a few exceptions.
Mitigations are in place to protect against Specter and Meltdown. See the Specter and Meltdown KnowledgeBase article for more details about the remediation and configuration options .
bolt and thunderbolt-tools have been promoted to provide security controls for Thunderbolt devices.
Default CIFS / SMB protocol version change in CIFS mounts
Since 17.10, the default SMB protocol used when mounting remote CIFS filesystems via mount.cifs (from the cifs-utils package) changed to 2.1 or higher, depending on what is negotiated with the server. If no version is specified:
No dialect specified on mount. Default has changed to a more secure dialect, SMB2.1 or later (e.g., SMB3), from CIFS (SMB1). To use the less secure SMB1 dialect to access old servers which do not support SMB3 (or SMB2.1) specify vers = 1.0 on mount.
Should you encounter compatibility issues, like # 1764778 or # 1572132 please specify verse = 1.0 when mounting the share and please file a problem if you fix it