Announcing the Unbreakable Enterprise Kernel Release 5 Update 3 for Oracle Linux

March 23, 2020 | 3 minute read
Simon Coter
Director, Oracle Linux and Virtualization Product Management
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The Unbreakable Enterprise Kernel (UEK) for Oracle Linux provides the latest open source innovations and key optimizations and security to enterprise cloud workloads. It is the Linux kernel that powers Oracle Cloud and Oracle Engineered Systems such as Oracle Exadata Database Machine as well as Oracle Linux on Intel-64, AMD-64 or ARM hardware.

What's New?

UEK R5 Update 3 is based on the mainline kernel version 4.14.35. Through actively monitoring upstream check-ins and collaboration with partners and customers, Oracle continues to improve and apply critical bug and security fixes to the Unbreakable Enterprise Kernel (UEK) R5 for Oracle Linux. This update includes several new features, added functionality, and bug fixes across a range of subsystems.

UEK R5 Update 3 can be recognized with release number starting with 4.14.35-1902.300.

Notable changes:

  • 64-bit Arm (aarch64) Architecture. Significant improvements have been made to a number of drivers, through vendor contributions, for better support on embedded 64-bit Arm platforms.
  • Core Kernel Functionality. UEK R5U3 provides equivalent core kernel functionality to UEK R5U2, making use of the same upstream mainline kernel release, with additional patches to enhance existing functionality and provide some minor bug fixes and security improvements.
  • On-Demand Paging. On-Demand-Paging (ODP) is a virtual memory management technique to ease memory registration.
  • File system and storage fixes
    • XFS.  A deadlock bug that caused the file system to freeze lock and not release has been fixed.
    • CIFS.  An upstream patch was applied to resolve an issue that could cause POSIX lock leakages and system crashes.
  • Virtualization and QEMU. Minor bugfix for hardware incompatibility with QEMU.  A minor bugfix was applied to KVM code in line with upstream fixes that resolved a trivial testing issue with certain versions of QEMU on some hardware.
  • Driver updates. In close cooperation with hardware and storage vendors, Oracle has updated several device drivers from the versions in mainline Linux 4.14.35; further updates are provided in the Appendix A (Driver Modules in Unbreakable Enterprise Kernel Release 5 Update 3) of the Release notes.

For more details on these and other new features and changes, please consult the Release Notes for the UEK R5 Update 3.

Security (CVE) Fixes

A full list of CVEs fixed in this release can be found in the Release Notes for the UEK R5 Update 3.

Supported Upgrade Path

Customers can upgrade existing Oracle Linux 7 servers using the Unbreakable Linux Network or the Oracle Linux yum server by pointing to "UEK Release 5" Yum Channel.

Software Download

Oracle Linux can be downloaded, used, and distributed free of charge and all updates and errata are freely available. This allows organizations to decide which systems require a support subscription and makes Oracle Linux an ideal choice for development, testing, and production systems. The user decides which support coverage is the best for each system individually, while keeping all systems up-to-date and secure. Customers with Oracle Linux Premier Support also receive access to zero-downtime kernel updates using Oracle Ksplice.


UEK R5 Update 3 is fully compatible with the UEK R5 GA release. The kernel ABI for UEK R5 remains unchanged in all subsequent updates to the initial release.

About Oracle Linux

The Oracle Linux operating system is engineered for an open cloud infrastructure. It delivers leading performance, scalability and reliability for enterprise SaaS and PaaS workloads as well as traditional enterprise applications. Oracle Linux Support offers access to award-winning Oracle support resources and Linux support specialists; zero-downtime updates using Ksplice; additional management tools such as Oracle Enterprise Manager and Spacewalk; and lifetime support, all at a low cost. And unlike many other commercial Linux distributions, Oracle Linux is easy to download, completely free to use, distribute, and update.
Oracle tests the UEK intensively with demanding Oracle workloads, and recommends the UEK for Oracle deployments and all other enterprise deployments.

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Simon Coter

Director, Oracle Linux and Virtualization Product Management

A 20-years Oracle veteran, Simon Coter is an experienced product manager and open source community member. He leads a team responsible for several Oracle Linux and Virtualization offerings, including Oracle Linux, the Unbreakable Enterprise Kernel for Oracle Linux, Oracle Cloud Native Environment, Oracle Linux KVM, Oracle Linux Virtualization Manager, Oracle Linux Automation Manager, Gluster, Oracle VM, and VirtualBox. Prior to this, Simon was a technical consultant focused on project management, architectures definition, sizing and implementation, best practices, and technical references for customers.

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