14 DAY TRIAL // Canonical released over the weekend new Linux kernel updates for Ubuntu 18.04 LTS (Bionic Beaver) users to fix a regression causing boot failures on some machines.
About two weeks ago, Canonical patched a regression that would lead to boot failures on some AMD machines using the Ubuntu 14.04 LTS (Trusty Tahr) operating system series, which was caused by a microcode firmware update for AMD processors that was supposed to mitigate the well-known Spectre microprocessor side-channel security vulnerability.
Earlier this month, on July 2, Canonical released a Linux kernel security update for Ubuntu 18.04 LTS (Bionic Beaver) users, addressing a total of six security vulnerabilities, one of which introduced a regression also causing boot failures, though it doesn't appear to be limited to AMD processors only, but also to Intel machines.
Now, the company behind one of the most popular Linux-based operating system released new kernel updates to fix the regression causing boot failures on 64-bit machines, as well as for OEM processors and systems running on Amazon Web Services (AWS), Microsoft Azure, Google Cloud Platform (GCP), and other cloud environments.
"USN-3695-1 fixed vulnerabilities in the Linux kernel for Ubuntu 18.04 LTS. Unfortunately, the fix for CVE-2018-1108 introduced a regression where insufficient early entropy prevented services from starting, leading in some situations to a failure to boot, This update addresses the issue. We apologize for the inconvenience," reads the security advisory.
The patch is also available for Ubuntu 16.04.4 LTS users with the HWE kernel
As Canonical allows users of previous Ubuntu LTS (Long Term Support) versions to use the Linux kernel of newer Ubuntu LTS versions, the patch for the said regression causing boot failures is also available for Ubuntu 16.04.4 LTS (Xenial Xerus) users that have the HWE (Hardware Enablement) kernel from Ubuntu 18.04 LTS (Bionic Beaver) installed by default.
All Ubuntu 18.04 LTS and Ubuntu 16.04 LTS users are urged to update their installations to the new Linux kernel versions that are available in the main software repositories as soon as possible and reboot their computers after a successful installation. While Ubuntu 18.04 LTS users need to update to linux-image 4.15.0-29.31, Ubuntu 16.04.4 LTS users must update to linux-image 4.15.0-29.31~16.04.1.