use of Wacom stylus causes immediate system hang with kernel 5.8.0-45, but 5.8.0-44 works

[Piotr Czekalski]

Once updated kernel from 5.8.0-44 to 5.8.0.45, any use of Wacom stylus causes immediate system hang, frozen both GUI and OS. Removing the Wacom kernel module solves the problem (no more hangs, but the stylus is unusable then).
Rolling back to kernel 5.8.0-44 or any earlier solves the problem.

The OS is: Ubuntu 20.04.2 LTS

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: linux-image-5.8.0-45-generic 5.8.0-45.51~20.04.1+1
ProcVersionSignature: Ubuntu 5.8.0-45.51~20.04.1-generic 5.8.18
Uname: Linux 5.8.0-45-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.16
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Sat Mar 20 18:53:56 2021
InstallationDate: Installed on 2020-04-24 (329 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
SourcePackage: linux-signed-hwe-5.8
UpgradeStatus: No upgrade log present (probably fresh install)

[Piotr Czekalski (pczekalski)]

The exact machine is a Lenovo Yoga X390.

Module causing hang is:
lsmod | grep wacom
wacom 118784 0
usbhid 57344 1 wacom
hid 135168 5 wacom,usbhid,hid_sensor_hub,intel_ishtp_hid,hid_generic

[Po-Hsu Lin (cypressyew)]

Hi,
thanks for reporting this,
there is a similar issue reported upstream [1] and the corresponding fix has landed on 5.8 Groovy kernel [2] with version 5.8.0-46.52, which should be available in the proposed pocket soon [3].

It should be available later in F-hwe kernel (5.8 kernel on Focal, which is the one you're using now), when the "Promote-to-proposed" task is set to "Fix Released" in this SRU tracking bug [4], the kernel will be available in the proposed pocket.
Can you give it a test later when it's available?

For how to enable proposed pocket please refer to this article [5].
Thanks

[1] https://github.com/linuxwacom/input-wacom/issues/230
[2] https://kernel.ubuntu.com/git/ubuntu/ubuntu-groovy.git/commit/?h=master-next&id=154b8e58b63235f257a02af0898175b3c6f70687
[3] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1918761
[4] https://bugs.launchpad.net/kernel-sru-workflow/+bug/1918760
[5] https://wiki.ubuntu.com/Testing/EnableProposed

[Piotr Czekalski (pczekalski)]

Sure, I can test with the new kernel, once available. Just enabled pre-released updates according to the manual [5], but so far, apt update && apt upgrade do not bring any new kernel. Is this already published via proposed channel?

[Po-Hsu Lin (cypressyew)]

Hi,
thanks for trying this out, they're not ready yet, you will have to wait until the "Promote-to-proposed" task in bug 1918760 changed to Fix-released.

[Piotr Czekalski (pczekalski)]

I saw kernel 5.8.0-48 has been released.
I've updated 5.8.0-44 to 5.8.0-48 and it didn't help, unfortunately. Any use of Wacom stylus causes immediately OS hung and unresponsive. Rolling back to 5.8.0-44.

[Po-Hsu Lin (cypressyew)]

Hmm,
According to bug 1918761 the 5.8 kernel on Groovy hasn't reach the proposed pocket yet.

[Daniel van Vugt (vanvugt)]

Groovy is already ahead:

Updates: 5.8.0-48.54
Proposed: 5.8.0-45.51

[Po-Hsu Lin (cypressyew)]

Ah ok,
looks like that's for Security fixes (CVEs):

linux (5.8.0-48.54) groovy; urgency=medium

  * CVE-2020-27170
    - bpf: Fix off-by-one for area size in creating mask to left

  * CVE-2020-27171
    - bpf: Prohibit alu ops for pointer types not defining ptr_limit

https://launchpad.net/ubuntu/+source/linux/5.8.0-48.54

Please wait for the kernel of the upcoming SRU cycle, which should be available soon.

[Piotr Czekalski (pczekalski)]

Thanks for handling the issue. I see I missed the update. I'll wait then, till the new kernel is available.
Should I report results here?

BTW - how do I ensure that kernel is in 5.8.0-48 (or any other?).
All I can get from 'uname -r' is i.e. 5.8.0-44-generic without the bugfix version.

Regards,

P.

[Po-Hsu Lin (cypressyew)]

Hello,
The bug fix could be found in the changelog:
https://launchpad.net/ubuntu/+source/linux/KERNEL_VERSION

Change the KERNEL_VERSION here with the corresponding one.

The fix commit has now rebased and tagged with Ubuntu-5.8.0-49.55
I will try to update here once the kernel is available.
Thanks

[Po-Hsu Lin (cypressyew)]

Hello folks,

the proposed Groovy kernel is now available:
https://launchpad.net/ubuntu/+source/linux/5.8.0-49.55

With commit:
    - HID: wacom: Correct NULL dereference on AES pen proximity

Please give it a test, you can get this proposed kernel with instructions here:
https://wiki.ubuntu.com/Testing/EnableProposed

You can turn this off after the test.
Thanks

[Daniel van Vugt (vanvugt)]

Note; most people experiencing this bug are using focal so may not be able to test groovy fixes.

[Arvid Norlander (vorpalblade)]

Shouldn't there be a proposed fix for the hwe kernel of focal as well so we can test?

As I understood it (and please correct me if I'm wrong), the HWE kernel is simply the kernel from a newer Ubuntu release (currently groovy) rebuilt with the older toolchain of an LTS release (currently focal). Seems it should be trivial for you to just make the build server built both with minimal effort?

I'd love to help test this once there is a package for focal available.

[Po-Hsu Lin (cypressyew)]

Hello,
yes there will be one, please see the status of this tracking bug https://bugs.launchpad.net/kernel-sru-workflow/+bug/1921052
It will be ready when the "Promote-to-proposed" task flipped to Fix-released.
Thanks

[jomuller (jomuller)]

Tested fixed kernel (5.8.0-49) with the pre-released updates channel as Po-Hsu Lin suggested. It works perfectly, wacom pen bug fixed.
Thanks !

[Piotr Czekalski (pczekalski)]

Tested kernel 5.8.0-49 on Ubuntu 20.04.
I acknowledge it works perfectly now. The bug is fixed.
Thank you for all your great effort.

[Craig McQueen (cmcqueen1975)]

I'm seeing this issue in groovy with kernel 5.8.0.48.53. Has the fix regressed in the later kernel?

[Daniel van Vugt (vanvugt)]

The fix has not been released yet. It's apparently coming in:

https://launchpad.net/ubuntu/+source/linux/5.8.0-49.55

[Jesko (jeskowastaken)]

Today I updated the released to 5.8.0-49. I works perfectly now.