Re: port-amd64/55661: pppoe renegotiation timeout causing panic

[Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>]

The following reply was made to PR port-amd64/55661; it has been noted by GNATS.

From: Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: port-amd64/55661: pppoe renegotiation timeout causing panic
Date: Wed, 16 Sep 2020 10:37:29 +0900

 Hi,
 
 It seems that your system saved core dump.  Could you show the backtrace?
 E.g. do the following command
 # crash /var/crash/netbsd.X.core.gz /var/crash/netbsd.X.gz  # "X" is the latest number
 crash> bt
 
 
 Thanks,
 
 On 2020/09/15 16:10, pr%xn--rvztrtkrfrgp-bbb7j2b8f0b9d7a21oft.com@localhost wrote:
 >> Number:         55661
 >> Category:       port-amd64
 >> Synopsis:       pppoe renegotiation timeout causing panic
 >> Confidential:   no
 >> Severity:       serious
 >> Priority:       medium
 >> Responsible:    port-amd64-maintainer
 >> State:          open
 >> Class:          sw-bug
 >> Submitter-Id:   net
 >> Arrival-Date:   Tue Sep 15 07:10:00 +0000 2020
 >> Originator:     Ben Gergely
 >> Release:        9.99.72
 >> Organization:
 >> Environment:
 > NetBSD 9.99.72 amd64
 >> Description:
 > Kinda hard to debug because it requires my ISP to fall on it's face.
 > 
 > I didnt manage to grab the other panic that mentioned an xcall which didnt get tee'd to the log.
 > 
 > I'm assuming the panics are from trying to renegotiate a pppoe session after a PADI timeout, I've not got a pppd log to check specifically what happened just before but a timeout it's an educated guess based on what what was happening with the ISP.
 > 
 > 
 > 
 > Sep 15 03:46:27 sludge /usr/sbin/ifwatchd[731]: watching interface pppoe0
 > Sep 15 03:46:27 sludge npfd: reopening pcap socket
 > Sep 15 03:46:27 sludge npfd: 167 packets read from `/var/log/npflog0.pcap'
 > Sep 15 03:46:27 sludge savecore: reboot after panic: [   7.6760811] panic: kernel diagnostic assertion "(l->l_pflag & LP_INTR) == 0 || panicstr != NULL" failed: file "/usr/src/sys/kern/kern_condvar.c", line 126
 > Sep 15 03:46:27 sludge savecore: system went down at Tue Sep 15 03:45:45 2020
 > 
 > Sep 15 04:47:55 sludge /usr/sbin/ifwatchd[731]: watching interface pppoe0
 > Sep 15 04:47:55 sludge npfd: reopening pcap socket
 > Sep 15 04:47:55 sludge npfd: 176 packets read from `/var/log/npflog0.pcap'
 > Sep 15 04:47:55 sludge savecore: reboot after panic: [   9.0854538] panic: kernel diagnostic assertion "(l->l_pflag & LP_INTR) == 0 || panicstr != NULL" failed: file "/usr/src/sys/kern/kern_condvar.c", line 126
 > Sep 15 04:47:55 sludge savecore: system went down at Tue Sep 15 04:47:14 2020
 > 
 > Sep 15 05:11:25 sludge savecore: reboot after panic: [   7.6538159] panic: kernel diagnostic assertion "(l->l_pflag & LP_INTR) == 0 || panicstr != NULL" failed: file "/usr/src/sys/kern/kern_condvar.c", line 126
 > Sep 15 05:11:25 sludge savecore: system went down at Tue Sep 15 05:10:44 2020
 > 
 > Sep 15 06:24:33 sludge /usr/sbin/ifwatchd[731]: watching interface pppoe0
 > Sep 15 06:24:33 sludge npfd: reopening pcap socket
 > Sep 15 06:24:33 sludge npfd: 176 packets read from `/var/log/npflog0.pcap'
 > Sep 15 06:24:33 sludge savecore: reboot after panic: [   7.8855546] panic: kernel diagnostic assertion "(l->l_pflag & LP_INTR) == 0 || panicstr != NULL" failed: file "/usr/src/sys/kern/kern_condvar.c", line 126
 > Sep 15 06:24:33 sludge savecore: system went down at Tue Sep 15 06:23:52 2020
 > 
 > Sep 15 07:01:02 sludge /usr/sbin/ifwatchd[731]: watching interface pppoe0
 > Sep 15 07:01:02 sludge npfd: reopening pcap socket
 > Sep 15 07:01:02 sludge npfd: 177 packets read from `/var/log/npflog0.pcap'
 > Sep 15 07:01:02 sludge savecore: reboot after panic: [   7.2022737] panic: kernel diagnostic assertion "(l->l_pflag & LP_INTR) == 0 || panicstr != NULL" failed: file "/usr/src/sys/kern/kern_condvar.c", line 126
 > Sep 15 07:01:02 sludge savecore: system went down at Tue Sep 15 07:00:21 2020
 > 
 >> How-To-Repeat:
 > Get your ISP's backhaul to fail so pppoe sessions timeout and endlessly try to renegotiate.
 > 
 > Might work on a tunnel, not tried yet.
 >> Fix:
 > 
 
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 Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>