========================================================================== Ubuntu Security Notice USN-3522-4 January 10, 2018 linux-lts-xenial regression ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 14.04 LTS Summary: USN-3522-2 introduced a regression in the Linux Hardware Enablement kernel. Software Description: - linux-lts-xenial: Linux hardware enablement kernel from Xenial for Trusty Details: USN-3522-2 fixed a vulnerability in the Linux Hardware Enablement kernel for Ubuntu 14.04 LTS to address Meltdown (CVE-2017-5754). Unfortunately, that update introduced a regression where a few systems failed to boot successfully. This update fixes the problem. We apologize for the inconvenience. Original advisory details: Jann Horn discovered that microprocessors utilizing speculative execution and indirect branch prediction may allow unauthorized memory reads via sidechannel attacks. This flaw is known as Meltdown. A local attacker could use this to expose sensitive information, including kernel memory. Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 14.04 LTS: linux-image-4.4.0-109-generic 4.4.0-109.132~14.04.1 linux-image-4.4.0-109-lowlatency 4.4.0-109.132~14.04.1 linux-image-generic-lts-xenial 4.4.0.109.92 linux-image-lowlatency-lts-xenial 4.4.0.109.92 After a standard system update you need to reboot your computer to make all the necessary changes. ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well. References: https://www.ubuntu.com/usn/usn-3522-4 https://www.ubuntu.com/usn/usn-3522-1 https://launchpad.net/bugs/1741934, https://usn.ubuntu.com/usn/usn-3522-2 Package Information: https://launchpad.net/ubuntu/+source/linux-lts-xenial/4.4.0-109.132~14.04.1