usb-modeswitch segfaults when connecting a HUAWEI E173

[Andres Rodriguez]

When connecting a USB 3G modem (HUAWEI E173), usb_modeswitch segfaults and the device is not recognized as a modem:

Syslog output:

n 24 14:45:33 pursue kernel: [ 1072.926833] usb 2-1.2: new high-speed USB device number 4 using ehci_hcd
Jan 24 14:45:33 pursue mtp-probe: checking bus 2, device 4: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2"
Jan 24 14:45:33 pursue mtp-probe: bus: 2, device: 4 was not an MTP device
Jan 24 14:45:33 pursue kernel: [ 1073.023345] scsi8 : usb-storage 2-1.2:1.0
Jan 24 14:45:33 pursue kernel: [ 1073.023819] scsi9 : usb-storage 2-1.2:1.1
Jan 24 14:45:33 pursue kernel: [ 1073.036193] show_signal_msg: 57 callbacks suppressed
Jan 24 14:45:33 pursue kernel: [ 1073.036202] usb_modeswitch_[5010]: segfault at 0 ip 00007f3b33365541 sp 00007ffff0a97728 error 4 in libc-2.13.so[7f3b332df000+197000]
Jan 24 14:45:34 pursue kernel: [ 1074.025122] scsi 9:0:0:0: Direct-Access HUAWEI SD Storage 2.31 PQ: 0 ANSI: 2
Jan 24 14:45:34 pursue kernel: [ 1074.025126] scsi 8:0:0:0: CD-ROM HUAWEI Mass Storage 2.31 PQ: 0 ANSI: 2
Jan 24 14:45:34 pursue kernel: [ 1074.025783] sd 9:0:0:0: Attached scsi generic sg1 type 0
Jan 24 14:45:34 pursue kernel: [ 1074.035047] sr0: scsi-1 drive

[Launchpad Janitor (janitor)]

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

[mahfiaz (mahfiaz)]

I get the same as well. Any workaround?

[ 3215.928226] usb_modeswitch_[16853]: segfault at 8 ip 00007f9c0152e541 sp 00007fff27d32a58 error 4 in libc-2.13.so[7f9c014a8000+197000]

[Mathieu Trudel-Lapierre (cyphermox)]

There's a simple workaround (though I'm still working on a proper fix):

edit /lib/udev/usb_modeswitch, change the line:
exec /usr/sbin/usb_modeswitch_dispatcher $1 $2 2>/dev/null

to

exec /usr/sbin/usb_modeswitch_dispatcher $1 $2 >/dev/null 2>&1

In other words, simply make sure any output is redirected to /dev/null.

[mahfiaz (mahfiaz)]

This removed the segfault error from the dmesg. But it seems like removing error does not solve the problem, NetworkManager still shows no modem.