kernel bug null pointer dereference

[Corben]

After upgrading to linux-image-4.15.0-44-generic via the update manager today, I can't log in anymore. The login screen appears, but as soon as I've entered my password and hit enter, the desktop locks up, keyboard stops working and display goes black. Network is still working, so I could login remotely and see the crash live via journalctl. I attached the full output of journalctl -k -b -1

In short it says

BUG: unable to handle kernel NULL pointer dereference at 0000000000000245
IP: intel_ddi_post_disable+0x54/0x170 [i915]
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI

Infos about my hardware:

lsb_release -rd
Description: Ubuntu 18.04.1 LTS
Release: 18.04

apt-cache policy linux-image-4.15.0-44-generic
linux-image-4.15.0-44-generic:
  Installiert: 4.15.0-44.47
  Installationskandidat: 4.15.0-44.47
  Versionstabelle:
 *** 4.15.0-44.47 500
        500 http://de.archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu bionic-security/main amd64 Packages
        100 /var/lib/dpkg/status

Rebooting to the previous kernel 4.15.0-43 doesn't have this issue and I can login without issues.

[Corben (tobias-krummen)]

Looks like the file wasn't attached.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1813796

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Corben (tobias-krummen)]

Maybe this is related to https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1813795

When I boot my surface pro 3 without being attached to the docking station, it boots and I can log in.
After being logged in, I can attach the docking station (with 2 additional monitors) and it keeps working.

[Corben (tobias-krummen)]

How do I add the missing files?

apport-collect 1813796 returns:

dpkg-query: no packages found matching linux

[Detro (detronizator)]

I have the exact same issue with:
- Lenovo X260 (Core i5 - 16GB RAM)
- Lenovo Thinkpad Pro Dock 40A10065UK

I have tested and reproduced with both Ubuntu and Kubuntu.
I have also tested changing GDM3 to LightDM, to SDDM, as the freeze happened when they were about to load and I thought it was a problem with GDM3 initially: the freeze always happen.

[Detro (detronizator)]

Forgot to mention: Ubuntu and Kubuntu were both 18.04.1

[Ethan Moss (ethanmoss)]

This issue is occurring on my HP Elitebook 1040 G4 with the HP Elite USB-C dock

[Darin Cummins (darin-cummins)]

Also happening on a Dell Precision 5520. Works fine without doc. Screen goes black and system locks up after login if docked. Cold boot is only option.

Booting to 4.15.0-43 works fine.

[Juha Luoma (jsluoma)]

My laptop (HP EliteBook 850 G2) hangs on attempt to suspend with similar looking backtrace. Hard poweroff is required to recover.

[Miika Launiainen (miicat)]

Also happening on Lenovo ThinkPad T470. External screen won't get any signal and laptop screen shows is black. No mouse. When I booted from linux-image-4.15.0-43-generic, it worked normally

[Paul Lieverse (paul-lieverse)]

Same issue on Dell Precision 5530

[Adrien (adrien-lecharpentier)]

I have the same issue on a Lenovo T460s. Booting on 4.15.0.43 fixed the problem.
It seems that the log files were attached in the second message, but do you need something else?

[clubber (fkramer)]

I can confirm this problem. And it seems to be largely hardware independent and happens on various Lenovo T450s and T440s devices with dock

[Michael (7-ubuntu-0)]

I can confirm that with a Dell Precision and a Thunderbold Dock 16.
Booting to 4.15.0-43 works fine.

[Marijan Matić (mmatic37)]

I can confirm the issue wit HP Elitebook 840 g4/g5 models and dock. Kernel .0-43 works fine .0-44 doesn't

[DaveyPocket (daveypocket)]

Having the same issue with Dell XPS 9570 and Dell Thunderbolt dock. Occasionally, connecting to dock AFTER system booted will not cause crash. Going into suspend when connected to dock or disconnecting from dock causes this issue.

[Nikhil Anand (anandnick321)]

I had similar problem with my Thinkpad X1 and Thinkpad Thunderbolt dock.
Updating to the newest release of kernel (4.15.0-45-generic) today morning fixed the issue