ModemManager dies (core dump) on free() call

[Hrvoje]

Hi.

With latest update, something changed, and now ModemManager is dying with SIGSEGV in free() call. Since it is configured as "respawn" in upstart scripts, it's clogging syslog, and adding additional load on cpu - it's restarting quite fast.

What is expected:

That modem manager is running.

What happened:

The modemmanager process is fast re-spawning and dying every time, clogging syslog and adding to cpu load.

Package info:

Version is 1.0.0-2ubuntu1.1, running on latest 14.04.01 (3.13.0-71-generic, #114), 64bit arch.

Additional info:

I'm experiencing this on at least two machines, with similar hardware (same 3G modem), different other stuff. This did not happen before last update - i think!

Here is the trace (full size attached):

*** Error in `ModemManager': free(): invalid pointer: 0x00000000011ba2a0 ***
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x7338f)[0x7f958a98f38f]
/lib/x86_64-linux-gnu/libc.so.6(+0x81fb6)[0x7f958a99dfb6]
/usr/lib/x86_64-linux-gnu/ModemManager/libmm-plugin-dell.so(+0x578a)[0x7f9585b6978a]
ModemManager[0x4901fb]
ModemManager[0x48db73]
ModemManager[0x48f76b]
/lib/x86_64-linux-gnu/libglib-2.0.so.0(g_main_context_dispatch+0x135)[0x7f958af47ce5]
/lib/x86_64-linux-gnu/libglib-2.0.so.0(+0x49048)[0x7f958af48048]
/lib/x86_64-linux-gnu/libglib-2.0.so.0(g_main_loop_run+0x6a)[0x7f958af4830a]
ModemManager(main+0xf6)[0x428fa6]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf5)[0x7f958a93dec5]
ModemManager[0x429102]
======= Memory map: ========
00400000-004df000 r-xp 00000000 fc:01 421732 /usr/sbin/ModemManager
006de000-006e0000 r--p 000de000 fc:01 421732 /usr/sbin/ModemManager
006e0000-006e3000 rw-p 000e0000 fc:01 421732 /usr/sbin/ModemManager
006e3000-006e4000 rw-p 00000000 00:00 0
01189000-0121d000 rw-p 00000000 00:00 0 [heap]
7f9583cdb000-7f9583cf1000 r-xp 00000000 fc:01 1311237 /lib/x86_64-linux-gnu/libgcc_s.so.1
7f9583cf1000-7f9583ef0000 ---p 00016000 fc:01 1311237 /lib/x86_64-linux-gnu/libgcc_s.so.1
7f9583ef0000-7f9583ef1000 rw-p 00015000 fc:01 1311237 /lib/x86_64-linux-gnu/libgcc_s.so.1

This is how kernel initializes card (tty USB ports):

[ 15.031607] usbcore: registered new interface driver usbserial
[ 15.031661] usbcore: registered new interface driver usbserial_generic
[ 15.031711] usbserial: USB Serial support registered for generic
[ 15.038822] usbcore: registered new interface driver option
[ 15.038910] usbserial: USB Serial support registered for GSM modem (1-port)
[ 15.039071] option 4-2:1.0: GSM modem (1-port) converter detected
[ 15.039516] usb 4-2: GSM modem (1-port) converter now attached to ttyUSB0
[ 15.039564] option 4-2:1.1: GSM modem (1-port) converter detected
[ 15.039973] usb 4-2: GSM modem (1-port) converter now attached to ttyUSB1

Listing of USB devices:

Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 007 Device 003: ID 0483:2016 STMicroelectronics Fingerprint Reader
Bus 007 Device 004: ID 0b97:7772 O2 Micro, Inc. OZ776 CCID Smartcard Reader
Bus 007 Device 002: ID 0b97:7761 O2 Micro, Inc. Oz776 1.1 Hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 002: ID 413c:8137 Dell Computer Corp. Wireless 5520 Voda L Mobile Broadband (3G HSDPA) Minicard Status Port
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 002: ID 413c:8140 Dell Computer Corp. Wireless 360 Bluetooth
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

WORKAROUND!

ModemManager works by disabling free check. THIS IS DANGEROUS, since it can have other. To do this, start ModemManager with "MALLOC_CHECK_" environment set to 0.

Regards,

H.