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. ** Attachment added: "Screenshot of the null pointer dereference message" https://bugs.launchpad.net/ubuntu/+source/linux-signed/+bug/1777338/+attachment/5153715/+files/Screenshot.png -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-signed in Ubuntu. https://bugs.launchpad.net/bugs/1777338 Title: Linux 4.15.0-23 crashes during the boot process with a "Unable to handle kernel NULL pointer dereference" message Status in linux-signed package in Ubuntu: New Bug description: 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-4.15.0-23-generic 4.15.0-23.25 ProcVersionSignature: Ubuntu 4.15.0-22.24-generic 4.15.17 Uname: Linux 4.15.0-22-generic x86_64 NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair 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-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: linux-signed UpgradeStatus: Upgraded to bionic on 2018-05-29 (19 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-signed/+bug/1777338/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
