Thinkpad X250 blanks and locks up when removed from the docking station

My X250 has worked with the docking station for just over three years but the latest kernel update (4.15.0-45-generic) seems to have broken the ability to undock.

To reproduce:

1. Turn the laptop on and log in.
2. Dock the laptop.
3. Undock the laptop.

This leaves the computer in an unresponsive state (screen is black, keyboard input of any kind doesn't do anything) and I have to force a shutdown.

If the laptop screen dims while docked, the computer also has be force restarted. If you dock the laptop before booting the computer, it doesn't boot and is in the same locked state.

moorepants@garuda:~$ lsb_release -rd
Description: Ubuntu 18.04.1 LTS
Release: 18.04

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-4.15.0-45-generic 4.15.0-45.48
ProcVersionSignature: Ubuntu 4.15.0-45.48-generic 4.15.18
Uname: Linux 4.15.0-45-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: moorepants 2514 F.... pulseaudio
 /dev/snd/controlC0: moorepants 2514 F.... pulseaudio
CurrentDesktop: Unity:Unity7:ubuntu
Date: Sat Feb 2 12:24:29 2019
EcryptfsInUse: Yes
HibernationDevice: RESUME=UUID=00333301-992b-4a3e-a93f-f6ace66eec1d
InstallationDate: Installed on 2015-11-14 (1176 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
MachineType: LENOVO 20CMCTO1WW
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-45-generic root=UUID=180cbbee-84f0-4f5d-8f67-ab39fe37099a ro quiet splash vt.handoff=1
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-45-generic N/A
 linux-backports-modules-4.15.0-45-generic N/A
 linux-firmware 1.173.3
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/19/2015
dmi.bios.vendor: LENOVO
dmi.bios.version: N10ET36W (1.15 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20CMCTO1WW
dmi.board.vendor: LENOVO
dmi.board.version: SDK0J40709 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.modalias: dmi:bvnLENOVO:bvrN10ET36W(1.15):bd06/19/2015:svnLENOVO:pn20CMCTO1WW:pvrThinkPadX250:rvnLENOVO:rn20CMCTO1WW:rvrSDK0J40709WIN:cvnLENOVO:ct10:cvrNone:
dmi.product.family: ThinkPad X250
dmi.product.name: 20CMCTO1WW
dmi.product.version: ThinkPad X250
dmi.sys.vendor: LENOVO