crash in nf_nat_cleanup_conntrack without any trace in log files

[Vincent Ladeuil]

This is the second time (unclear about a third one) I encounter this crash and all I could do was power-cycling to reboot.

/var/crash is empty

/var/log/syslog and /var/log/kern.log don't contain any hint around the crash time (the subsequent reboot is present though).

So I took a picture (attached) :-}

The last time this bug occurred, I was destroying a juju env with 13 lxcs instances but I've since done it again without reproducing the issue (and I do it on a ~regular basis without triggering the bug).

Hopefully the traceback can provide some hints ?

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-30-generic 3.13.0-30.54
ProcVersionSignature: Ubuntu 3.13.0-30.54-generic 3.13.11.2
Uname: Linux 3.13.0-30-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC2: vila 13341 F.... pulseaudio
 /dev/snd/controlC1: vila 13341 F.... pulseaudio
 /dev/snd/controlC3: vila 13341 F.... pulseaudio
 /dev/snd/controlC0: vila 13341 F.... pulseaudio
CurrentDesktop: Unity
Date: Wed Jul 2 18:37:20 2014
InstallationDate: Installed on 2011-06-23 (1105 days ago)
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64+mac (20110427.1)
MachineType: System manufacturer System Product Name
ProcFB: 0 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-30-generic root=UUID=9e03ea1c-298d-4b96-9870-4db1fe183774 ro quiet splash
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-30-generic N/A
 linux-backports-modules-3.13.0-30-generic N/A
 linux-firmware 1.127.4
RfKill:
 0: hci0: Bluetooth
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
UpgradeStatus: Upgraded to trusty on 2014-04-08 (85 days ago)
dmi.bios.date: 09/21/2010
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 2209
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: P6T DELUXE
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr2209:bd09/21/2010:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnP6TDELUXE:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer

[Brad Figg (brad-figg)]

This change was made by a bot.

[Vincent Ladeuil (vila)]

Just occurred again and indeed that was when running 'juju destroy-environment lxc --force'

The only thing that is not standard in my config is that I'm using an existing 'br0' bridge in /etc/lxc/default.conf (lxc.network.link = br0) and I disable /etc/default/lxc-net with (USE_LXC_BRIDGE="false").

Does it help triaging ? I'm not sure (at all) that the kernel is at fault here.

[Vincent Ladeuil (vila)]

FTR, issuing 'juju destroy-environment lxc --force' after the reboot completes.

[Vincent Ladeuil (vila)]

I'm testing the kernel mentioned in bug #1314274 as this bug seems to be a duplicate, will mark it as such if I don't get a crash in the next days.

Note that I had to http://www.ubuntuupdates.org/package/canonical_kernel_team/trusty/main/base/linux-headers-3.13.0-31 in addition to the packages provided at http://people.canonical.com/~arges/lp1314274.trusty/ to get a proper install

[gdm85 (gdm85)]

If this is same bug as upstream:
https://bugzilla.kernel.org/show_bug.cgi?id=65191

Then please merge the related upstream commit:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=945b2b2d259d1a4364a2799e80e8ff32f8c6ee6f

Downstream related tracker on Docker project:

https://github.com/dotcloud/docker/issues/2960

[gdm85 (gdm85)]

I noticed on https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1314274 that a fix is going to be released for Trusty, and if this is a duplicate that will properly address the issue. Sorry for the noise.

[penalvch (penalvch)]

Vincent Ladeuil, did the fix from https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1314274 address your issue? If so, please feel free to mark this bug report a duplicate of it. If not, could you please advise?

[Vincent Ladeuil (vila)]

@Christopher, sorry had a tab opened (but never came back to it) to confirm I'm now running 3.13.0-32-generic #57-Ubuntu which includes the fix and I didn't encounter the bug anymore (while still heavily using the offending config/command) so I'm confident it's fixed.