NetworkManager crashes/segfault - sometimes

Question

Sometimes at startup networkmanager crashes. Usually it's fine - it seems to be random and I cannot intentionally duplicate it. My system is 64-bit and fully updated. Other than this - no issues - no failed services or errors - other than this when it occurs. Here's what I see in the logs when it happens:
systemd-coredump[938]: Process 484 (NetworkManager) of user 0 dumped core.
-- Subject: Process 484 (NetworkManager) dumped core
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- Documentation: man:core(5)
-- Process 484 (NetworkManager) crashed and dumped core.
-- This usually indicates a programming error in the crashing program and
-- should be reported to its vendor as a bug.
[ 46.003130] NetworkManager[484]: segfault at 2 ip 00000000004871b2 sp 00007ffffabcb750 error 4 in NetworkManager[400000+109000]
My setup is luks on lvm with XFCE. I have ipv6 disabled in the kernel (ipv6.disable=1) and have added the following entries to my dhcpcd conf file:
noipv6rs
noipv6
noarp
I'm pretty sure that I've got all the necessary components installed because it usually works fine: networkmanager networkmanager-openvpn network-manager-applet xfce4-notifyd
I do connect to openvpn when I connect to the wireless network but switching off the automatic connection to the vpn doesn't prevent networkmanager's problems.
If I try to restart networkmanager (systemctl restart NetworkManager.service) I get the following error messages:
dhcpcd already running on pid 589 (/run/dhcpcd-wlp3s0.pid)
I run Arch on 2 laptops and a pc and they each suffer from this - but again it's intermittent.
Any ideas, suggestions would be great. At the moment I can resolve it only by rebooting.
Thanks,
Jules

Answer 1

Kinokoio wrote:Your setup is not a problem, so the mistake may be in nm. Try filing a bug so it gets a deep research.
Before filing a bug report without any real info for the devs I would try to debug it at least a bit myself.
See the following links for more information:
https://wiki.gnome.org/Projects/Network … /Debugging
http://www.freedesktop.org/wiki/Softwar … Debugging/ (It's about ModemManager but you'll get the hang of it)
Especially I would try to alter the service file for NetworkManager to include the --log-level= parameter.
Further, playing around with gdb might get some insight.
See links:
https://wiki.archlinux.org/index.php/Core_dump
http://www.randombugs.com/linux/core-dumps-linux.html
https://mytechrants.wordpress.com/2009/ … using-gdb/
http://www.cs.cmu.edu/~gilpin/tutorial/
http://stackoverflow.com/questions/8305 … -dump-file
Maybe downgrading is an option too.
It's a bit of work to do, but I don't think filing a bug report at this state is going to help.
Last edited by MK13 (2015-01-12 08:33:42)