Comment 50 for bug 1802021

@mfo

Just to confirm that we installed the right proposed version of the kernel as this doesn't have any steps to reproduce. It only reproduces randomly after a certain amount of time.
These are the steps we followed to install

echo 'deb http://archive.ubuntu.com/ubuntu/ xenial-proposed restricted main multiverse universe' > /etc/apt/sources.list.d/kernel.list
echo -e "Package: *\nPin: release a=xenial-proposed\nPin-Priority: 400" > /etc/apt/preferences.d/proposed-updates
apt-get -t xenial-proposed install -y linux-image-unsigned-4.15.0-47-generic
reboot

Installed packages
dpkg -l | grep -i 4.15.0-47
ii linux-image-unsigned-4.15.0-47-generic 4.15.0-47.50~16.04.1 amd64 Linux kernel image for version 4.15.0 on 64 bit x86 SMP
ii linux-modules-4.15.0-47-generic 4.15.0-47.50~16.04.1 amd64 Linux kernel extra modules for version 4.15.0 on 64 bit x86 SMP

dpkg -l | grep -i hwe
ii linux-generic-hwe-16.04 4.15.0.45.66 amd64 Complete Generic Linux kernel and headers
ii linux-headers-generic-hwe-16.04 4.15.0.45.66 amd64 Generic Linux kernel headers
ii linux-image-generic-hwe-16.04 4.15.0.45.66 amd64 Generic Linux kernel image

uname -a
Linux myhostname 4.15.0-47-generic #50~16.04.1-Ubuntu SMP Fri Mar 15 16:06:21 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux