The patches addressing the Meltdown vulnerabilities in Ubuntu 16.04 LTS are causing issues that Windows users have already encountered. Many systems are unable to boot after installing the latest kernel updates from Canonical.
Ubuntu users began reporting boot issues after Canonical added kernel updates to mitigate Meltdown, and according to recent reports, systems were affected after upgrading from kernel 4.4.0-104 to 4.4.0-108.
Canonical quickly acknowledged the issue and shipped kernel updates 4.4.0-109 and 4.4.0-109.114 to fix the bugs, but at this point it is not yet known how many devices were affected by the initial issue. Unfortunately, there are reports that the new kernel makes no difference to systems experiencing the boot error, although this has not been confirmed yet.
In case Canonical's latest kernel updates do not address the boot issue, the only workaround is to revert to version 4.4.0-104 which appears to fix the bug, but in turn leaves computers without patches for hardware defects.
Compared to similar issues on Windows, Ubuntu boot errors do not seem to affect AMD systems. We will likely have more details on this issue in the near future.
For information, the first company to release patches for Meltdown and Spectre is Microsoft, with several users reporting boot problems on computers running Windows 7, 8.1 and 10 with AMD hardware.
