Hardy Hangs with looping "unregister_netdevice: waiting for ppp0 to become free. Usage count = 1" on console

[Raghu Udiyar]

It appears to be a deadlock problem with a net device not being able to be released.

This happens when two pppoe connections are in use at the same time with an ipsec tunnel using racoon.
Then, intermittently the server just hangs with the following looping message.

unregister_netdevice: waiting for ppp0 to become free. Usage count = 1

The only option is to reboot the server.

It's a regression bug and supposedly fixed in 2.6.24 series. But the problem still persists.

To reproduce:

1. Two pppoe connections
2. Establish IP-sec tunnel with racoon
3. System defintly hangs after a while ( less then 24 hrs)

Also, the two connections are very unsteady which reults in lot of if ups/downs which in a combination with the
ip-sec tunnel I suppose triggers the problem

ProblemType: Bug
Architecture: amd64
Date: Sat Sep 26 11:03:20 2009
Dependencies:

DistroRelease: Ubuntu 8.04
Package: linux None [modified: /var/lib/dpkg/info/linux.list]
PackageArchitecture: amd64
ProcEnviron:
 PATH=/usr/lib/kde4/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/X11R6/bin
 LANG=en_IN
 SHELL=/bin/bash
SourcePackage: linux-meta
Uname: Linux 2.6.24-24-server x86_64

[kernel-janitor (kernel-janitor)]

[This is an automated message. Apologies if it has reached you inappropriately.]

This bug was reported against the linux-meta package when it likely should have been reported against the linux package instead. We are automatically transitioning this to the linux kernel package so that the appropriate teams are notified and made aware of this issue.

If this bug really is a bug in the linux-meta package you can move it back to linux-meta and set the Status to Confirmed, or contact us on the #ubuntu-kernel channel on the FreeNode IRC server. Thanks.

[Philip Craig (philipc)]

This sounds like it would be fixed by commit 58ec3b4db9eb5a28e3aec5f407a54e28f7039c19 in linux 2.6.27.

[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 437045

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.

[Raghu Udiyar (raags)]

Seems to be fixed as per comment #2, more details here : https://lkml.org/lkml/2008/11/7/459