disable CONFIG_KFENCE_STATIC_KEYS in linux 5.15

[Andrea Righi]

[Impact]

KFENCE devs are changing CONFIG_KFENCE_STATIC_KEYS to be disabled by default, because it's introducing more problems than benefits:

https://<email address hidden>/T/#u

This also seems to trigger QEMU bugs during the systemd autopkgtest, like:
https://bugs.launchpad.net/qemu/+bug/1920934

[Test case]

Run systemd autopkgtest.

[Fix]

Disable CONFIG_KFENCE_STATIC_KEYS.

[Regression potential]

We may experience an overall performance regression for not using static branches in the KFENCE code.

[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 1948038

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.

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu Jammy) because there has been no activity for 60 days.]

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 5.15.0-17.17

---------------
linux (5.15.0-17.17) jammy; urgency=medium

  * jammy/linux: 5.15.0-17.17 -proposed tracker (LP: #1957809)

 -- Andrea Righi <email address hidden> Thu, 13 Jan 2022 17:11:21 +0100

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

This bug is awaiting verification that the linux-oracle-5.15/5.15.0-1006.8~20.04.1 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-focal' to 'verification-done-focal'. If the problem still exists, change the tag 'verification-needed-focal' to 'verification-failed-focal'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!