no wifi after upgrading to 17.10

[Geoff Williams]

Overview
========
After upgrading Xubuntu 17.04 to 17.10, wifi stopped working completely

Expected behaviour
==================
Wifi should continue to work after an OS upgrade

Actual behaviour
================
Wifi not available, no driver loaded

Analysis
========
System reports wifi as Broadcom Limited BCM4352 802.11ac Wireless Network Adapter (rev 03), in Additional Drivers, Linux STA driver from bcmwl-kernel-source is shown as selected

Attempting to reconfigure bcmwl-kernel-source gives an error:
geoff@monster:~$ sudo dpkg-reconfigure bcmwl-kernel-source
Removing all DKMS Modules
Done.
Loading new bcmwl-6.30.223.271+bdcom DKMS files...
Building for 4.13.0-16-lowlatency
Building for architecture x86_64
Module build for kernel 4.13.0-16-lowlatency was skipped since the
kernel headers for this kernel does not seem to be installed.
modprobe: FATAL: Module wl not found in directory /lib/modules/4.13.0-16-lowlatency
update-initramfs: deferring update (trigger activated)
Processing triggers for initramfs-tools (0.125ubuntu12) ...
update-initramfs: Generating /boot/initrd.img-4.13.0-16-lowlatency
cryptsetup: WARNING: target cryptswap1 has a random key, skipped
Processing triggers for shim-signed (1.32+0.9+1474479173.6c180c6-1ubuntu1) ...
Secure Boot not enabled on this system.

Looks like the upgrade didn't install the kernel headers which meant no WIFI on reboot

Workaround
==========
Installing the appropriate kernel headers and reconfiguring bcmwl-kernel-source fixed my system immediately

Connect wired Ethernet then:
sudo apt-get install linux-headers-$(uname -r)
sudo dpkg-reconfigure bcmwl-kernel-source

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: ubuntu-release-upgrader-core 1:17.10.7
ProcVersionSignature: Ubuntu 4.13.0-16.19-lowlatency 4.13.4
Uname: Linux 4.13.0-16-lowlatency x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.7-0ubuntu3
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: XFCE
Date: Sat Oct 21 19:53:58 2017
EcryptfsInUse: Yes
InstallationDate: Installed on 2014-09-23 (1123 days ago)
InstallationMedia: Xubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.2)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
Symptom: ubuntu-release-upgrader
UpgradeStatus: Upgraded to artful on 2017-10-21 (0 days ago)
VarLogDistupgradeTermlog:

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[gyr9i (gyr9i-a)]

Thank you so much! Your workaround has helped me! As I remember the same situation was when I had upgraded from 16.04 to 17.10

[Eric Heim (eheimwbn)]

Thanks Geoff, your workaround worked for me!

[Brian Murray (brian-murray)]

This is strange as from your log files we can see that the linux-headers-generic package is installed and the new linux-headers package gets installed (VarLogDistupgradeAptterm.log).

Selecting previously unselected package linux-headers-4.13.0-16.
Preparing to unpack .../610-linux-headers-4.13.0-16_4.13.0-16.19_all.deb ...
Unpacking linux-headers-4.13.0-16 (4.13.0-16.19) ...
Selecting previously unselected package linux-headers-4.13.0-16-generic.
Preparing to unpack .../611-linux-headers-4.13.0-16-generic_4.13.0-16.19_amd64.deb ...
Unpacking linux-headers-4.13.0-16-generic (4.13.0-16.19) ...
Preparing to unpack .../612-linux-headers-generic_4.13.0.16.17_amd64.deb ...
Unpacking linux-headers-generic (4.13.0.16.17) over (4.10.0.37.37) ...

[Brian Murray (brian-murray)]

Oh, I think its because you did not have the lowlatency headers installed e.g. linux-headers-lowlatency.

[Brian Murray (brian-murray)]

How did you go about installing the lowlatency kernel?

[Geoff Williams (geoff-geoffwilliams)]

Brian, good question. I assumed it was the upgrade but it wansn't. I've done some digging and found this:

geoff@monster:~$ aptitude why linux-image-4.13.0-16-lowlatency
i docker-engine Recommends aufs-tools
i A aufs-tools Recommends aufs-dkms
i A linux-image-4.13.0-16-lowlatency Provides aufs-dkms

I'd installed the docker-engine package *ages* ago and forgotten about it. This is what dragged in the lowlatency kernel.

I'm pretty sure my ^^^^ fix will fail on the next kernel update too since the longterm fix would be:

sudo apt-get install linux-headers-lowlatency

As you mentioned

[Launchpad Janitor (janitor)]

[Expired for ubuntu-release-upgrader (Ubuntu) because there has been no activity for 60 days.]