Linux 4.15.0-23 crashes during the boot process with a "Unable to handle kernel NULL pointer dereference" message
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Fix Released
|
High
|
Unassigned | ||
Bionic |
Fix Released
|
High
|
Unassigned |
Bug Description
== SRU Justification ==
Mainline commit 1f50ddb4f418 introduced a regression. That commit added
speculative_
However, speculative_
PV guests, as well.
The regresssion prevents systems from booting.
The patch to fix this regression has also been cc'd to upstream stable,
but it has not landed in Bionic as of yet.
== Fix ==
74899d92e666 ("x86/xen: Add call of speculative_
== Regression Potential ==
Low. This patch fixes a current regressionThis patch has also been
submitted to upstream stable, so it has had additional upstream review.
== Test Case ==
A test kernel was built with this patch and tested by the original bug reporter.
The bug reporter states the test kernel resolved the bug.
I went to boot my computer today and it wouldn't boot.
I get an "Unable to handle kernel NULL pointer dereference" message during the boot process, and, a bit after that, a message from the kernel watchdog about CPU #0 being stuck. Then the boot process stops completely.
I was able to boot the system by telling Grub to load 4.15.0-22, which works perfectly fine, so there has been a regression.
I am running Ubuntu as a Xen dom0, if that matters. I haven't tried booting the offending kernel version without Xen.
I'm not sure where, if anywhere, these messages go on disk, for posting.
ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-
ProcVersionSign
Uname: Linux 4.15.0-22-generic x86_64
NonfreeKernelMo
ApportVersion: 2.20.9-0ubuntu7.1
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Sun Jun 17 10:12:58 2018
InstallationDate: Installed on 2017-08-06 (314 days ago)
InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412)
ProcEnviron:
TERM=xterm-
PATH=(custom, no user)
XDG_RUNTIME_
LANG=en_US.UTF-8
SHELL=/bin/bash
SourcePackage: linux-signed
UpgradeStatus: Upgraded to bionic on 2018-05-29 (19 days ago)
CVE References
affects: | linux-signed (Ubuntu) → linux (Ubuntu) |
Changed in linux (Ubuntu): | |
importance: | Undecided → High |
status: | New → In Progress |
Changed in linux (Ubuntu Bionic): | |
importance: | Undecided → High |
status: | New → In Progress |
assignee: | nobody → Joseph Salisbury (jsalisbury) |
Changed in linux (Ubuntu): | |
assignee: | nobody → Joseph Salisbury (jsalisbury) |
Changed in linux (Ubuntu Bionic): | |
status: | In Progress → Fix Committed |
Changed in linux (Ubuntu): | |
status: | In Progress → Fix Committed |
tags: |
added: verification-done-bionic removed: verification-needed-bionic |
tags: | added: cscc |
Changed in linux (Ubuntu): | |
status: | Fix Committed → Fix Released |
This also affects the mainline kernel build 4.17.0- 041700. 201806041953 that I was testing for another bug.
I've attached a photo of the screen with the issue occurring, in that version.
Booting not under Xen seems to work around the issue, and the system comes up, but that's not useful for me because I need Xen.