4.15.0-23-generic fails to boot in qemu on amd64 host (kernel panic)

[Aurélien COUDERC]

Trying to boot bionic with 4.15.0-23-generic fails with a kernel panic in qemu on an Debian amd64 host.
The version of qemu is the current in Debian Testing: 2.12+dfsg-3.

Booting with 4.15.0-22-generic works fine.
---
ProblemType: Bug
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: zouzou 1274 F.... pulseaudio
CurrentDesktop: ubuntu-communitheme:ubuntu:GNOME
DistroRelease: Ubuntu 18.04
InstallationDate: Installed on 2017-07-12 (338 days ago)
InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Alpha amd64 (20170710)
IwConfig:
 lo no wireless extensions.

 ens3 no wireless extensions.
MachineType: QEMU Standard PC (i440FX + PIIX, 1996)
Package: linux-signed (not installed)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
ProcFB: 0 qxldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-22-generic root=UUID=26da642a-bbc4-440b-bed3-a911bbbfe582 ro quiet splash
ProcVersionSignature: Ubuntu 4.15.0-22.24-generic 4.15.17
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-22-generic N/A
 linux-backports-modules-4.15.0-22-generic N/A
 linux-firmware 1.173.1
RfKill:

Tags: bionic
Uname: Linux 4.15.0-22-generic x86_64
UpgradeStatus: Upgraded to bionic on 2018-02-07 (128 days ago)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
_MarkForUpload: True
dmi.bios.date: 04/01/2014
dmi.bios.vendor: SeaBIOS
dmi.bios.version: 1.11.1-1
dmi.chassis.type: 1
dmi.chassis.vendor: QEMU
dmi.chassis.version: pc-i440fx-2.8
dmi.modalias: dmi:bvnSeaBIOS:bvr1.11.1-1:bd04/01/2014:svnQEMU:pnStandardPC(i440FX+PIIX,1996):pvrpc-i440fx-2.8:cvnQEMU:ct1:cvrpc-i440fx-2.8:
dmi.product.name: Standard PC (i440FX + PIIX, 1996)
dmi.product.version: pc-i440fx-2.8
dmi.sys.vendor: QEMU

[Aurélien COUDERC (coucouf)]

apport information

[Aurélien COUDERC (coucouf)]

apport information

[Aurélien COUDERC (coucouf)]

Apport info is obviously from the booting kernel, I’ll try to also get some useful information from the panic in the VT.

[Aurélien COUDERC (coucouf)]

Kernel log says:

Failed to execute /init (error -2)
Kernel panic - not syncing: No working init found. Try passing init= option to kernel. [...]

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.17 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.18-rc1

[wayne (vwxyz)]

I have tried with this mainline kernel ver 4.18 rc1 (http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.18-rc1) and has no kernel panic problem.

[Joseph Salisbury (jsalisbury)]

Can you next test the upstream 4.15.18 stable kernel:
http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.15.18/

If 4.15.18 still has the bug, we can perform a reverse kernel bisect to identify the fix in mainline.

[Aurélien COUDERC (coucouf)]

Hmm, I had missed that :

$ sudo update-initramfs -u -k 4.15.0-23-generic
update-initramfs: Generating /boot/initrd.img-4.15.0-23-generic
modinfo: ERROR: could not get modinfo from 'qxl': Exec format error
depmod: ERROR: failed to load symbols from /var/tmp/mkinitramfs_a65BM0/lib/modules/4.15.0-23-generic/kernel/drivers/gpu/drm/qxl/qxl.ko: Exec format error

Side note : all upstream kernel packages I tested *do* boot correctly:
- 4.15.16, 4.15.17, 4.15.18
- 4.16.16
- 4.17.2

[wayne (vwxyz)]

Tested 4.15.18 (http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.15.18/)
I boots normally with no kernel panic problem.

[wayne (vwxyz)]

When tested with main line version 4.17.2 (http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.17.2/), kernel panic problem resurfaces.

[Joseph Salisbury (jsalisbury)]

I built a test kernel with a revert of Bionic commit 494f8f20811baf580370f7d65bb7ea615ec37882. The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1777242

Can you test this kernel and see if it resolves this bug?

Note about installing test kernels:
• If the test kernel is prior to 4.15(Bionic) you need to install the linux-image and linux-image-extra .deb packages.
• If the test kernel is 4.15(Bionic) or newer, you need to install the linux-modules, linux-modules-extra and linux-image-unsigned .deb packages.

Thanks in advance!

[wayne (vwxyz)]

Tested with 4.15.0-23 ~lp1777242 (http://kernel.ubuntu.com/~jsalisbury/lp1777242) kernel. It solves the bug.

[Joseph Salisbury (jsalisbury)]

Bionic commit 494f8f20811baf5 is a revert of Bionic commit dc0f16f9b50. This was done for bug 1728238. We will investigate further to find a solution.

[Aurélien COUDERC (coucouf)]

I can confirm 4.15.0-23.26~lp1777242 is installing and booting fine.

Thanks for your quick feedbacks. :)

[Joseph Salisbury (jsalisbury)]

I built a v2 test kernel. The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1777242

Can you test this kernel and see if it resolves this bug?

Also, can you post the output from dmesg?

[Aurélien COUDERC (coucouf)]

It kind of works but takes forever to start due to crng initialization.
(Forever like I didn’t wait and ended up pressing some random keys to get things moving after more than a minute.)

[ 6.163871] 8139cp 0000:00:03.0 ens3: link up, 100Mbps, full-duplex, lpa 0x05E1
[ 97.338260] random: crng init done

This problem was not present in former kernel versions.

dmesg attached.

[wayne (vwxyz)]

Tested this v2 test kernel. The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1777242

No problems from my side.