BUG: unable to handle kernel NULL pointer dereference at 0000000000000020

[Michael Wood]

No idea what caused this.
I booted the machine, logged in, started the Software Updater to check for updates and then walked away. When I got back, Software Updater said it had failed to download repository information. I told it to retry, and about that time I got the notification that something had crashed.
I see the stack trace mentions nouveau and hotplug. I did not plug/unplug any external monitors or do anything other than what was mentioned above before this Oops happened.

ProblemType: KernelOops
DistroRelease: Ubuntu 17.10
Package: linux-image-4.13.0-16-generic 4.13.0-16.19 [modified: boot/vmlinuz-4.13.0-16-generic]
ProcVersionSignature: Ubuntu 4.13.0-16.19-generic 4.13.4
Uname: Linux 4.13.0-16-generic x86_64
Annotation: Your system might become unstable now and might need to be restarted.
ApportVersion: 2.20.7-0ubuntu3
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/pcmC0D0p: michael 1395 F...m pulseaudio
 /dev/snd/controlC0: michael 1395 F.... pulseaudio
Date: Sat Feb 3 14:37:00 2018
DuplicateSignature: BUG: unable to handle kernel NULL pointer dereference at location RIP: nv50_mstm_service+0x18/0xb0 [nouveau] RSP: ffffb2dfc03e3dc0
Failure: oops
InstallationDate: Installed on 2017-10-21 (104 days ago)
InstallationMedia: Ubuntu-MATE 17.10 "Artful Aardvark" - Release amd64 (20171018)
MachineType: Apple Inc. MacBookAir3,2
ProcFB: 0 nouveaufb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.13.0-16-generic.efi.signed root=UUID=74e1bbab-f267-43f4-9c5f-0f102a968bc2 ro quiet splash vt.handoff=7
PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions: kerneloops-daemon N/A
SourcePackage: linux
Title: BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/18/10
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBA31.88Z.0061.B01.1011181342
dmi.board.asset.tag: Base Board Asset Tag#
dmi.board.name: Mac-942C5DF58193131B
dmi.board.vendor: Apple Inc.
dmi.board.version: MacBookAir3,2
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-942C5DF58193131B
dmi.modalias: dmi:bvnAppleInc.:bvrMBA31.88Z.0061.B01.1011181342:bd11/18/10:svnAppleInc.:pnMacBookAir3,2:pvr1.0:rvnAppleInc.:rnMac-942C5DF58193131B:rvrMacBookAir3,2:cvnAppleInc.:ct10:cvrMac-942C5DF58193131B:
dmi.product.family: MacBook
dmi.product.name: MacBookAir3,2
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.

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

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Did this issue start happening after an update/upgrade? Was there a prior kernel version where you were not having this particular problem?

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.15 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/v4.15

[Launchpad Janitor (janitor)]

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