Crash in Modem-Manager on Ubuntu

[Ajay Garg <ajaygargnsit gmail com>]

Hi All.

I am using Ubuntu, and achieve the following crash when trying to
connect to a Mobile-Broadband connection ::


Last few-logs ::
------------------------

########################################################################
ModemManager[11586]: <info>  Modem
/org/freedesktop/ModemManager1/Modem/0: 3GPP Registration state
changed (unknown -> registering)
ModemManager[11586]: <info>  Modem
/org/freedesktop/ModemManager1/Modem/0: 3GPP Registration state
changed (registering -> home)
ModemManager[11586]: <info>  Modem
/org/freedesktop/ModemManager1/Modem/0: 3GPP location updated (MCC:
'0', MNC: '0', Location area code: '79C4', Cell ID: '7925EE')
ModemManager[11586]: <info>  Modem
/org/freedesktop/ModemManager1/Modem/0: 3GPP location updated (MCC:
'404', MNC: '10', Location area code: '79C4', Cell ID: '7925EE')
ModemManager[11586]: mm_serial_port_close: assertion 'priv->open_count
> 0' failed
ModemManager[11586]: <info>  Modem
/org/freedesktop/ModemManager1/Modem/0: state changed (enabling ->
registered)
ModemManager[11586]: <info>  (tty/ttyUSB0): released by modem
/sys/devices/pci0000:00/0000:00:14.0/usb1/1-4/1-4.1
ModemManager[11586]: <info>  (tty/ttyUSB2): released by modem
/sys/devices/pci0000:00/0000:00:14.0/usb1/1-4/1-4.1
ModemManager[11586]: <info>  (tty/ttyUSB4): released by modem
/sys/devices/pci0000:00/0000:00:14.0/usb1/1-4/1-4.1
ModemManager[11586]: <info>  (tty/ttyUSB3): released by modem
/sys/devices/pci0000:00/0000:00:14.0/usb1/1-4/1-4.1
ModemManager[11586]: <info>  Simple connect started...
ModemManager[11586]: <info>  Simple connect state (4/8): Wait to get
fully enabled
ModemManager[11586]: <info>  Simple connect state (5/8): Register
ModemManager[11586]: <info>  Simple connect state (6/8): Bearer
########################################################################



Backtrace ::
------------------------

########################################################################
Program received signal SIGSEGV, Segmentation fault.
0x08073234 in mm_bearer_get_path ()
(gdb) bt
#0  0x08073234 in mm_bearer_get_path ()
#1  0xb6fabc67 in ?? () from
/usr/lib/i386-linux-gnu/ModemManager/libmm-plugin-sierra-legacy.so
#2  0x08086173 in ?? ()
#3  0xb7c984c5 in g_simple_async_result_complete () from
/usr/lib/i386-linux-gnu/libgio-2.0.so.0
#4  0xb6fabd92 in ?? () from
/usr/lib/i386-linux-gnu/ModemManager/libmm-plugin-sierra-legacy.so
#5  0xb7c984c5 in g_simple_async_result_complete () from
/usr/lib/i386-linux-gnu/libgio-2.0.so.0
#6  0xb7c9852b in ?? () from /usr/lib/i386-linux-gnu/libgio-2.0.so.0
#7  0xb7b10c50 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#8  0xb7b140a7 in g_main_context_dispatch () from
/lib/i386-linux-gnu/libglib-2.0.so.0
#9  0xb7b14468 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#10 0xb7b1476b in g_main_loop_run () from /lib/i386-linux-gnu/libglib-2.0.so.0
#11 0x0806869d in main ()
########################################################################


I see an identical reported bug at
https://bugzilla.redhat.com/show_bug.cgi?id=1089094, however there was
no progress there due to EOL of the OS.

I tried on Ubuntu-14 on Linux-Kernel-3.16 and Linux-Kernel-4.2, and
behaviour is same.

The modemmanager version is 1.0.0-2ubuntu1.1 on both.
I tried "apt-get install", but I am told it is the latest-version available.

Not sure whether really this is in domain of NM-guys or kernel-guys,
so ccing both :)

Any ideas of a fix/workaround?


Thanks and Regards,
Ajay