NetworkManager crashed with SIGSEGV in nm_dhcp_dhclient_escape_duid()

[Elbert Fliek]

NetworkManager crashed after booting and connecting to a new problem.
Then it restarted and crashed again multiple times until it connected properly.

ProblemType: Crash
DistroRelease: Ubuntu 13.04
Package: network-manager 0.9.8.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.8.0-11.20-generic 3.8.2
Uname: Linux 3.8.0-11-generic i686
ApportVersion: 2.9.1-0ubuntu1
Architecture: i386
Date: Sun Mar 10 18:35:04 2013
ExecutablePath: /usr/sbin/NetworkManager
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2013-03-09 (1 days ago)
InstallationMedia: Xubuntu 13.04 "Raring Ringtail" - Alpha i386 (20130309)
InterestingModules: b44
IpRoute:
 default via 192.168.1.1 dev eth1 proto static
 169.254.0.0/16 dev eth1 scope link metric 1000
 192.168.1.0/24 dev eth1 proto kernel scope link src 192.168.1.26 metric 9
MarkForUpload: True
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
 WimaxEnabled=true
ProcCmdline: NetworkManager
ProcEnviron:
 TERM=linux
 PATH=(custom, no user)
 LANG=en_US.UTF-8
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SegvAnalysis:
 Segfault happened at: 0x80cca26 <nm_dhcp_dhclient_escape_duid+22>: mov 0x4(%esi),%eax
 PC (0x080cca26) ok
 source "0x4(%esi)" (0x00000004) not located in a known VMA region (needed readable region)!
 destination "%eax" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: network-manager
StacktraceTop:
 nm_dhcp_dhclient_escape_duid ()
 ?? ()
 nm_dhcp_client_start_ip6 ()
 ?? ()
 nm_dhcp_manager_start_ip6 ()
Title: NetworkManager crashed with SIGSEGV in nm_dhcp_dhclient_escape_duid()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:

nmcli-con:
 NAME UUID TYPE TIMESTAMP TIMESTAMP-REAL AUTOCONNECT READONLY DBUS-PATH
 Wired connection 1 43c10ef8-5a8e-4565-87c8-16f805c2e895 802-3-ethernet 1362936962 zo 10 mrt 2013 18:36:02 CET yes no /org/freedesktop/NetworkManager/Settings/2
 Groningerweg 38 76d7a8b5-1716-4b7d-ad57-f583fc1af359 802-11-wireless 1362936964 zo 10 mrt 2013 18:36:04 CET yes no /org/freedesktop/NetworkManager/Settings/1
 HG655D-F3913D 329d1a58-a4e6-4e67-a036-2e8b9eab3ad8 802-11-wireless 1362935293 zo 10 mrt 2013 18:08:13 CET yes no /org/freedesktop/NetworkManager/Settings/0
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH
 eth1 802-11-wireless connected /org/freedesktop/NetworkManager/Devices/1
 eth0 802-3-ethernet unavailable /org/freedesktop/NetworkManager/Devices/0
nmcli-nm:
 RUNNING VERSION STATE NET-ENABLED WIFI-HARDWARE WIFI WWAN-HARDWARE WWAN
 running 0.9.8.0 connected enabled enabled enabled enabled disabled

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Severin H (severinh)]

Prior to the segmentation fault, network-manager always emits the following warning in generate_duid_from_machine_id.

Failed to read /etc/machine-id to generate DHCPv6 DUID: (4) Failed to open file '/etc/machine-id': No such file or directory

The duid being NULL later leads to a null pointer dereference when attempting to escape it in nm_dhcp_dhclient_escape_duid. I'm not sure whether the call to generate_duid_from_machine_id was supposed to happen in the first place. If not, get_duid in nm-dhcp-dhclient.c would be to blame because it failed to obtain a duid and thus decided to generate one. It did not emit any warnings, though.

[Severin H (severinh)]

The problem is indeed that the file /etc/machine-id does not exist. You can work around the problem by creating it using the following command:

dbus-uuidgen | sudo tee /etc/machine-id

The file /etc/machine-id does not exist on Ubuntu machines because it is related to systemd. The official command for generating this file would be systemd-machine-id-setup, but it is not available on Ubuntu, so I abused dbus-uuidgen to achieve the same result. See http://www.freedesktop.org/software/systemd/man/systemd-machine-id-setup.html

network-manager should probably be patched such that it does not rely on the existence of this file.

[Severin H (severinh)]

I set the importance to High because the bug completetly prevented me from connecting to the wireless network at work.

[Ubuntu QA Website (ubuntuqa)]

This bug has been reported on the Ubuntu ISO testing tracker.

A list of all reports related to this bug can be found here:
http://iso.qa.ubuntu.com/qatracker/reports/bugs/1153342

[Mathieu Trudel-Lapierre (cyphermox)]

That file exists in a few other locations; /etc is just one of the possibilities. It actually comes from DBUS.

Regardless, full ack; we need to fix this ASAP. Seems like it's already corrected upstream by commit http://cgit.freedesktop.org/NetworkManager/NetworkManager/commit/?h=nm-0-9-8&id=1d14f17998bf0388db43b52e53690188e907cb01.

Setting to Triaged / Critical; let's land this in saucy (and SRU to Raring) ASAP.

[Launchpad Janitor (janitor)]

This bug was fixed in the package network-manager - 0.9.8.4-0ubuntu3

---------------
network-manager (0.9.8.4-0ubuntu3) trusty; urgency=low

  * Set "allow-stderr" for debian/tests/apparmor_workaround to avoid failure
    on AppArmor warnings.
 -- Martin Pitt <email address hidden> Tue, 05 Nov 2013 09:48:28 +0100

[Rolf Leggewie (r0lf)]

raring has seen the end of its life and is no longer receiving any updates. Marking the raring task for this ticket as "Won't Fix".

[Rolf Leggewie (r0lf)]

saucy has seen the end of its life and is no longer receiving any updates. Marking the saucy task for this ticket as "Won't Fix".