Kernel 4.4.0-31 Causes kernel panic at startup

[Robert Hrovat]

Latest kernel update 4.4.0-31 causes kernel panic at startup. Had to reboot with 4.4.0-28 which works fine. I have no idea if it's on all filesystems but I'm using btrfs.
---
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: robi 3230 F.... pulseaudio
 /dev/snd/pcmC1D0p: robi 3230 F...m pulseaudio
 /dev/snd/controlC1: robi 3230 F.... pulseaudio
CurrentDesktop: Unity
DistroRelease: Ubuntu 16.04
HibernationDevice: RESUME=UUID=d64a307b-b7ea-4308-b997-0587321ff7ea
InstallationDate: Installed on 2016-07-01 (21 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
MachineType: ASUSTeK COMPUTER INC. X750LN
NonfreeKernelModules: nvidia_uvm nvidia_modeset wl nvidia
Package: linux (not installed)
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-4.4.0-28-generic root=UUID=e075f560-d606-43a0-9cc3-5596a9416d30 ro rootflags=subvol=@ quiet splash
ProcVersionSignature: Ubuntu 4.4.0-28.47-generic 4.4.13
RelatedPackageVersions:
 linux-restricted-modules-4.4.0-28-generic N/A
 linux-backports-modules-4.4.0-28-generic N/A
 linux-firmware 1.157.2
Tags: xenial
Uname: Linux 4.4.0-28-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
_MarkForUpload: True
dmi.bios.date: 02/19/2014
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 201
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: X750LN
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: 1.0
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr201:bd02/19/2014:svnASUSTeKCOMPUTERINC.:pnX750LN:pvr1.0:rvnASUSTeKCOMPUTERINC.:rnX750LN:rvr1.0:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.name: X750LN
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK COMPUTER INC.

[Brad Figg (brad-figg)]

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1605731

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.

[Robert Hrovat (robi-hipnos)]

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[Robert Hrovat (robi-hipnos)]

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[Robert Hrovat (robi-hipnos)]

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[Robert Hrovat (robi-hipnos)]

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[Robert Hrovat (robi-hipnos)]

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[Robert Hrovat (robi-hipnos)]

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[Robert Hrovat (robi-hipnos)]

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[Robert Hrovat (robi-hipnos)]

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[Robert Hrovat (robi-hipnos)]

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[Robert Hrovat (robi-hipnos)]

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[Robert Hrovat (robi-hipnos)]

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[Robert Hrovat (robi-hipnos)]

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[Robert Hrovat (robi-hipnos)]

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[Robert Hrovat (robi-hipnos)]

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[Robert Hrovat (robi-hipnos)]

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[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream stable kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.4 stable 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'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-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/v4.4.15

[Joseph Salisbury (jsalisbury)]

Also, can you grab a screen shot or take a digital picture of the panic? Then attach it to the bug for review.

[Robert Hrovat (robi-hipnos)]

I removed that kernel and installed it again. This time, it didn't panic, but Wireless connection does not work.

[Joseph Salisbury (jsalisbury)]

So the panic does not happen anymore with the 4.4.0-31 kernel?

Can you open a new and separate bug report for your wireless issue?

[Seth Forshee (sforshee)]

@Robert: Is there any chance you forgot to install the linux-image-extra package? That would cause your wifi to fail to work.

[Robert Hrovat (robi-hipnos)]

@Seth, no, it's there.

[Robert Hrovat (robi-hipnos)]

But, I found out I didn't have linux-headers-generic installed, only linux-headers. Wi-Fi is working now.

[Robert Hrovat (robi-hipnos)]

It appears this kernel panic does not occur always. It happened again, and this time I managed to get a photo.

[Seth Forshee (sforshee)]

The kernel failed to mount the initial root filesystem, which should have been put into RAM by the bootloader. It's strange that this is failing, and even stranger that the failure is intermittent. It would be really nice to get the full dmesg from the kernel, but that's difficult when the kernel panics that early in boot.

Now that we know the problem is intermittent, I think the next reasonable step is to establish if this really is a regression since 4.4.0-28. How often does this happen in 4.4.0-31? If it's reasonably frequent and you can do enough successful reboots into 4.4.0-28 to give confidence that the bug doesn't exist there, then we could bisect to try and figure out which change introduced the bug.

[Robert Hrovat (robi-hipnos)]

It happens most of the time and random. I can't establish what is the difference when machine boots fine and when kernel panics. 4.4.0-28 always booted like it should.

[Joseph Salisbury (jsalisbury)]

The 4.4.0-34 kernel is available. Can you see if this bug still exists with -34?

[Robert Hrovat (robi-hipnos)]

It didn't happend since 4.4.0-34 so I guess it's fixed. Whatever the problem was.