Tested kernel from xenial-proposed on an affected system, and the issue there appears to be resolved.
$ uname -r 4.4.0-120-generic
$ apt policy linux-image-generic linux-image-generic: Installed: 4.4.0.120.126 Candidate: 4.4.0.120.126 Version table: *** 4.4.0.120.126 400 400 http://archive.ubuntu.com/ubuntu xenial-proposed/main amd64 Packages 100 /var/lib/dpkg/status 4.4.0.119.125 500 500 http://mirror.internode.on.net/pub/ubuntu/ubuntu xenial-security/main amd64 Packages 500 http://mirror.internode.on.net/pub/ubuntu/ubuntu xenial-updates/main amd64 Packages 4.4.0.21.22 500 500 http://mirror.internode.on.net/pub/ubuntu/ubuntu xenial/main amd64 Packages
$ apt policy intel-microcode intel-microcode: Installed: 3.20180312.0~ubuntu16.04.1 Candidate: 3.20180312.0~ubuntu16.04.1 Version table: *** 3.20180312.0~ubuntu16.04.1 500 500 http://mirror.internode.on.net/pub/ubuntu/ubuntu xenial-security/main amd64 Packages 500 http://mirror.internode.on.net/pub/ubuntu/ubuntu xenial-updates/main amd64 Packages 100 /var/lib/dpkg/status 3.20151106.1 500 500 http://mirror.internode.on.net/pub/ubuntu/ubuntu xenial/restricted amd64 Packages
Tested kernel from xenial-proposed on an affected system, and the issue there appears to be resolved.
$ uname -r
4.4.0-120-generic
$ apt policy linux-image-generic generic: archive. ubuntu. com/ubuntu xenial- proposed/ main amd64 Packages dpkg/status mirror. internode. on.net/ pub/ubuntu/ ubuntu xenial- security/ main amd64 Packages mirror. internode. on.net/ pub/ubuntu/ ubuntu xenial-updates/main amd64 Packages mirror. internode. on.net/ pub/ubuntu/ ubuntu xenial/main amd64 Packages
linux-image-
Installed: 4.4.0.120.126
Candidate: 4.4.0.120.126
Version table:
*** 4.4.0.120.126 400
400 http://
100 /var/lib/
4.4.0.119.125 500
500 http://
500 http://
4.4.0.21.22 500
500 http://
$ apt policy intel-microcode 0~ubuntu16. 04.1 0~ubuntu16. 04.1 0~ubuntu16. 04.1 500 mirror. internode. on.net/ pub/ubuntu/ ubuntu xenial- security/ main amd64 Packages mirror. internode. on.net/ pub/ubuntu/ ubuntu xenial-updates/main amd64 Packages dpkg/status mirror. internode. on.net/ pub/ubuntu/ ubuntu xenial/restricted amd64 Packages
intel-microcode:
Installed: 3.20180312.
Candidate: 3.20180312.
Version table:
*** 3.20180312.
500 http://
500 http://
100 /var/lib/
3.20151106.1 500
500 http://