kernel-packages team mailing list archive

[Tim Gardner <tim.gardner@xxxxxxxxxxxxx>]

** Changed in: linux (Ubuntu Precise)
       Status: In Progress => Fix Committed

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1021471

Title:
  clone() hang when creating new network namespace (dmesg show
  unregister_netdevice: waiting for lo to become free. Usage count = 2)

Status in The Linux Kernel:
  Confirmed
Status in “linux” package in Ubuntu:
  Fix Released
Status in “linux” source package in Precise:
  Fix Committed
Status in “linux” source package in Quantal:
  Fix Released

Bug description:
  SRU Justification:

  Impact:
      When creating new network namespace dmesg can show the following
      unregister_netdevice: waiting for lo to become free. Usage count = 1

  Fix:
      Stefan Bader's SAUCE patch has fixed this for Quantal:
      UBUNTU: SAUCE: net/ipv4: Always flush route cache on unregister batch call

  Testcase:
      The sourcecode found here:
      https://lists.debian.org/debian-kernel/2012/05/msg00494.html
      can be compiled and run as follows:

      sudo ./reproducer
      #ctrl+c
      sudo ./reproducer
      #wait for a while
      dmesg | grep unregister

  
  --

  I'm not sure how I triggered this. I've been moving around between
  networks and suspending/resuming all day.

  Earlier in this boot I successfully used a container (start,
  networking and stop). I came to start the same one later and noticed
  that it didn't come up. Trying to attach to the console with lxc-
  console informed me that it wasn't running. I then saw suspicious
  content in dmesg:

  [25800.412234] INFO: task lxc-start:25817 blocked for more than 120 seconds.
  [25800.412243] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [25800.412254] lxc-start       D ffff88013fd13980     0 25817      1 0x00000000
  [25800.412266]  ffff880007b43cc0 0000000000000086 ffff88003ba4c500 ffff880007b43fd8
  [25800.412275]  ffff880007b43fd8 ffff880007b43fd8 ffff880134c65c00 ffff88003ba4c500
  [25800.412284]  000080d0ffffffff ffffffff81ca7c00 ffff88003ba4c500 ffffffff81ca7c04
  [25800.412288] Call Trace:
  [25800.412306]  [<ffffffff81673759>] schedule+0x29/0x70
  [25800.412313]  [<ffffffff81673a1e>] schedule_preempt_disabled+0xe/0x10
  [25800.412323]  [<ffffffff81672537>] __mutex_lock_slowpath+0xd7/0x150
  [25800.412331]  [<ffffffff8167200a>] mutex_lock+0x2a/0x50
  [25800.412340]  [<ffffffff8155ede1>] copy_net_ns+0x71/0x100
  [25800.412350]  [<ffffffff8107adfb>] create_new_namespaces+0xdb/0x190
  [25800.412357]  [<ffffffff8107afec>] copy_namespaces+0x8c/0xd0
  [25800.412367]  [<ffffffff81050142>] copy_process.part.22+0x902/0x1520
  [25800.412375]  [<ffffffff81050ee5>] do_fork+0x135/0x390
  [25800.412385]  [<ffffffff8116db40>] ? kmem_cache_free+0x20/0x100
  [25800.412395]  [<ffffffff8118c6b3>] ? putname+0x33/0x50
  [25800.412402]  [<ffffffff811811cc>] ? do_sys_open+0x16c/0x200
  [25800.412410]  [<ffffffff8101c238>] sys_clone+0x28/0x30
  [25800.412418]  [<ffffffff8167cbf3>] stub_clone+0x13/0x20
  [25800.412424]  [<ffffffff8167c8e9>] ? system_call_fastpath+0x16/0x1b
  [25806.312385] unregister_netdevice: waiting for lo to become free. Usage count = 1

  ProblemType: Bug
  DistroRelease: Ubuntu 12.10
  Package: linux-image-generic 3.5.0.3.3
  ProcVersionSignature: Ubuntu 3.5.0-2.2-generic 3.5.0-rc4
  Uname: Linux 3.5.0-2-generic x86_64
  NonfreeKernelModules: nvidia wl
  AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.25.
  ApportVersion: 2.2.5-0ubuntu2
  Architecture: amd64
  ArecordDevices:
   **** List of CAPTURE Hardware Devices ****
   card 0: NVidia [HDA NVidia], device 0: Cirrus Analog [Cirrus Analog]
     Subdevices: 1/1
     Subdevice #0: subdevice #0
  AudioDevicesInUse:
   USER PID ACCESS COMMAND
   /dev/snd/controlC0:  laney      2787 F.... pulseaudio
  CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
  Card0.Amixer.info:
   Card hw:0 'NVidia'/'HDA NVidia at 0xd3480000 irq 22'
     Mixer name	: 'Nvidia MCP89 HDMI'
     Components	: 'HDA:10134206,106b0d00,00100301 HDA:10de000c,10de0101,00100200'
     Controls      : 37
     Simple ctrls  : 13
  Date: Thu Jul  5 21:26:08 2012
  HibernationDevice: RESUME=UUID=1c5b3f2c-2c89-4fa1-9ed8-0e238de8fe47
  InstallationMedia: Ubuntu 10.04.1 LTS "Lucid Lynx" - Release amd64 (20100729)
  MachineType: Apple Inc. MacBookPro7,1
  ProcFB: 0 VESA VGA
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.5.0-2-generic root=UUID=2228fdfe-3834-40b2-b7b4-efea7463e3c1 ro quiet splash reboot=pci vt.handoff=7
  RelatedPackageVersions:
   linux-restricted-modules-3.5.0-2-generic N/A
   linux-backports-modules-3.5.0-2-generic  N/A
   linux-firmware                           1.82
  SourcePackage: linux
  UpgradeStatus: Upgraded to quantal on 2012-01-13 (173 days ago)
  dmi.bios.date: 03/25/10
  dmi.bios.vendor: Apple Inc.
  dmi.bios.version: MBP71.88Z.0039.B05.1003251322
  dmi.board.name: Mac-F222BEC8
  dmi.board.vendor: Apple Inc.
  dmi.chassis.type: 10
  dmi.chassis.vendor: Apple Inc.
  dmi.chassis.version: Mac-F222BEC8
  dmi.modalias: dmi:bvnAppleInc.:bvrMBP71.88Z.0039.B05.1003251322:bd03/25/10:svnAppleInc.:pnMacBookPro7,1:pvr1.0:rvnAppleInc.:rnMac-F222BEC8:rvr:cvnAppleInc.:ct10:cvrMac-F222BEC8:
  dmi.product.name: MacBookPro7,1
  dmi.product.version: 1.0
  dmi.sys.vendor: Apple Inc.

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1021471/+subscriptions