Skip to contentSkip to conversation

2.6.24 regression: reference count leak in PPPoE

DISCUSSION Andi Kleen 8 participants 10 messages Jan 20, 2008 – Jan 21, 2008

Subsystems (2)
lore
Share & tools
lore

Andi Kleen

author
#0 lore raw

My workstation running 2.6.24-rc8 just hung during shutdown with an endless (or rather I didn't wait more than a few minutes) loop of

unregister_netdev: waiting for ppp-device to become free. Usage count = 1

ppp-device was an active PPPoE device.

No more information currently.

-Andi

#1 lore raw
Quoted 9 lines · Andi Kleen

My workstation running 2.6.24-rc8 just hung during shutdown with an endless (or rather I didn't wait more than a few minutes) loop of

unregister_netdev: waiting for ppp-device to become free. Usage count = 1

ppp-device was an active PPPoE device.

No more information currently.

i've seen such problems (locked up box with endless loop of usage count == 1) with pppoe in the past, and it seemed to be related to dynamic IPs. (i saw that well before 2.6.24 - reported it once to davem)

It seems to have stopped when i stopped using ipsec and started using vpnc. (but no firm info - this was sporadic - happened every few months or so) Are you using ipsec and dynamic IPs by any chance?

Ingo

author
#2 lore raw
Quoted 3 lines

It seems to have stopped when i stopped using ipsec and started using vpnc.

Kernel ipsec was active yes. However I normally don't see it although it is often active, that was the first time I think

(except long ago)

Quoted 2 lines

(but no firm info - this was sporadic - happened every few months or so) Are you using ipsec and dynamic IPs by any chance?

and the ISP uses dynamic IPs.

-Andi

maintainer
#3 lore raw
In reply to Ingo Molnar

From: Ingo Molnar <[email protected]>
Date: Sun, 20 Jan 2008 21:01:09 +0100

Quoted 9 lines · Andi Kleen
Quoted 7 lines

My workstation running 2.6.24-rc8 just hung during shutdown with an endless (or rather I didn't wait more than a few minutes) loop of

unregister_netdev: waiting for ppp-device to become free. Usage count = 1

Quoted 7 lines
Quoted 3 lines

ppp-device was an active PPPoE device.

No more information currently.

i've seen such problems (locked up box with endless loop of usage count == 1) with pppoe in the past, and it seemed to be related to dynamic IPs. (i saw that well before 2.6.24 - reported it once to davem)

No, this is a different bug Andi is seeing and it was recently introduced:

	http://bugzilla.kernel.org/show_bug.cgi?id=9778
#4 lore raw
In reply to Ingo Molnar

Hi.

Quoting Ingo Molnar <[email protected]>:

Quoted 13 lines · Andi Kleen
Quoted 10 lines

My workstation running 2.6.24-rc8 just hung during shutdown with an endless (or rather I didn't wait more than a few minutes) loop of

unregister_netdev: waiting for ppp-device to become free. Usage count = 1

ppp-device was an active PPPoE device.

No more information currently.

Quoted 7 lines

i've seen such problems (locked up box with endless loop of usage count == 1) with pppoe in the past, and it seemed to be related to dynamic IPs. (i saw that well before 2.6.24 - reported it once to davem)

It seems to have stopped when i stopped using ipsec and started using vpnc. (but no firm info - this was sporadic - happened every few months or so) Are you using ipsec and dynamic IPs by any chance?

This isn't PPPoE specific. It has also been seen with e1000, madwifi and an intel based card. It was introduced by a Jan 10 commit post rc7 (sorry, don't have the details right now - my laptop died yesterday). A bugzilla has already been opened.

Nigel

----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.

#5 lore raw
In reply to Andi Kleen
Quoted 6 lines · Andi Kleen

My workstation running 2.6.24-rc8 just hung during shutdown with an endless (or rather I didn't wait more than a few minutes) loop of

unregister_netdev: waiting for ppp-device to become free. Usage count = 1

ppp-device was an active PPPoE device.

Quoted 8 lines

No more information currently.

-Andi
--
To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html

I think this bug has been identified.

[Bug 9778] New: unregister_netdevice: waiting for [device] to become free

Thanks.
-- Daniel

#6 lore raw
In reply to Andi Kleen
Quoted 4 lines · Andi Kleen

My workstation running 2.6.24-rc8 just hung during shutdown with an endless (or rather I didn't wait more than a few minutes) loop of

unregister_netdev: waiting for ppp-device to become free. Usage count = 1

Same as http://lkml.org/lkml/2008/1/20/27? See also follow-up to that.

Cheers,
FJP

#7 lore raw
In reply to Andi Kleen
Quoted 9 lines · On Sun, 20 Jan 2008 20:53:30 +0100 Andi Kleen <[email protected]> wrote:

My workstation running 2.6.24-rc8 just hung during shutdown with an endless (or rather I didn't wait more than a few minutes) loop of

unregister_netdev: waiting for ppp-device to become free. Usage count = 1

ppp-device was an active PPPoE device.

No more information currently.

Now that you mention it, this happened to me too this morning. My system stops the ppp interface (pppoe) and starts it again (my provider shuts down the link every 24 hours, I want that to happen during the night, so I do a ifdown ppp0).

Signature · 5 lines
---------------------------------------
Malte Schröder
[email protected]
ICQ# 68121508
---------------------------------------
#8 lore raw
In reply to Andi Kleen

Hi!

Quoted 8 lines

My workstation running 2.6.24-rc8 just hung during shutdown with an endless (or rather I didn't wait more than a few minutes) loop of

unregister_netdev: waiting for ppp-device to become free. Usage count = 1

ppp-device was an active PPPoE device.

No more information currently.

Actually, I'm getting something similar:

usb 2-2: USB disconnect, address 23
PM: Removing info for No Bus:usbdev2.23_ep83
usb0: unregister 'cdc_ether' usb-0000:00:1d.0-2, CDC Ethernet Device
PM: Removing info for No Bus:usb0
unregister_netdevice: waiting for usb0 to become free. Usage count = 1
unregister_netdevice: waiting for usb0 to become free. Usage count = 1
unregister_netdevice: waiting for usb0 to become free. Usage count = 1
unregister_netdevice: waiting for usb0 to become free. Usage count = 1
unregister_netdevice: waiting for usb0 to become free. Usage count = 1
unregister_netdevice: waiting for usb0 to become free. Usage count = 1
PM: Removing info for usb:2-2:1.0
PM: Removing info for No Bus:usbdev2.23_ep81
PM: Removing info for No Bus:usbdev2.23_ep02

The unregister_netdevice made it onto console, that means pretty severe log level. Happened while playing with openmoko connected with USB cable.
Pavel

Signature · 2 lines
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html