MASTER - modem-manager crashed when tty disappears during "enable" - with SIGSEGV in dbus_connection_send()

StacktraceTop:_dbus_list_unlink (list=0x9eff7cc, link=0x9c) at dbus-list.c:509
_dbus_list_pop_first_link (list=0x9eff7cc)
_dbus_connection_preallocate_send_unlocked (
_dbus_connection_send_and_unlock (connection=0x9eff75c,
dbus_connection_send (connection=0x9eff75c,

what did you do when it crashed? can you reproduce this crash?

i do nothing...
i conect and surf the web (ubuntudanmark.dk, launchpad.net and facebook.com) i check mail (evolution) and use pidgin (irc, facebook chat and msn)

@Alex,

I get this crash when I try to connect to mobile ISP.
I use network-manager applet to select my ISP and in a few second I see a black notification popup bar next to it saying "Disconnected". In a few scond later ubuntu shows the crash icon and proposes to report a bug.

@Alex,

I get this trying to connect via builtin UMTS. This worked 2-3 weeks ago. Obviously newer patches broke it. This is on i386, latest patches as of today.

attached are the logs as described here: https://wiki.ubuntu.com/DebuggingModemmanager

the mm-test.py crashed though:

$ python ./mm-test.py
GSM modem
Driver: 'sierra'
Modem device: '/sys/devices/pci0000:00/0000:00:1d.2/usb7/7-1'
Data device: 'ttyUSB2'
Traceback (most recent call last):
  File "./mm-test.py", line 276, in <module>
    modem.Enable(True)
  File "/usr/lib/pymodules/python2.6/dbus/proxies.py", line 140, in __call__
    **keywords)
  File "/usr/lib/pymodules/python2.6/dbus/connection.py", line 620, in call_blocking
    message, timeout)
dbus.exceptions.DBusException: org.freedesktop.ModemManager.Modem.General: The modem was removed or disabled.

after test script exits with an error I see that this

sudo killall modem-manager; sudo modem-manager --debug 2>&1 | tee /tmp/modem.log.txt

is still running. Then I try to connect to my mobile ISP and get the described above crash. And I see that this

sudo killall modem-manager; sudo modem-manager --debug 2>&1 | tee /tmp/modem.log.txt

is terminated.

after some debugging in #nm we found that there are two issues here:

a) sierra modem goes down completely when sending CFUN=1 ... so we shouldnt do that.

b) crash of modemmanager when a tty disappears in the middle of activation.

i will open a new bug for a) and adjust this bug title.

the sierra bug (case a)) is bug 459052 ... please subscribe there if you were one of the sierra modem users that see this issue.

In my case this happened when starting up with my mobile internet Huawei E160G HSPDA Modem connected and WLAN disabled (my machine is a real one - Dell Latitude E5500 - no Virtual machine).

In my case it happened using mobile internet with a Huawei E220/270 HSDPA modem. The machine was a no-vm Dell Inspiron 5150.

BTW: My E160G shows up in lsusb as E220/270.

This bug somewhat related to https://bugs.launchpad.net/ubuntu/+source/linux/+bug/446146 or https://bugs.launchpad.net/ubuntu/+source/linux/+bug/449394 maybe?

Quite a number of duplicates, and nice stack trace; Mathieu, can you please check if this is still an issue?

Martin Wildam (or anyone else with similar Huawei or Sierra devices),

Can you still reproduce this crash on new releases (10.04, 10.10)?

Looking at the git tree for ModemManager, looks to me like it would still be the case, but I don't happen to have a Sierra gsm modem nor a Huawei E220 or E160G (I'll look for one though), so it's hard to tell whether it would still crash. At the moment, it looks like CFUN=1 would still get issued, but after a delay to give the modem time to initialize, which may have fixed the issues.

Closing the bug for now, please re open if you can reproduce with the latest version of Ubuntu, thanks.