KBlueMon crashes when scanning with service discovery enabled

[Joshua Kugler]

In KBlueMon, check "Discover Remote Services," and click "Start Scan." KBlueMon will crash with a seg fault.

I've tried this on two different systems (a laptop and desktop) both installed on the hard drive, and using the LiveCD. I've tried it with three different Bluetooth dongles (Kensington among them, don't have the others handy at the moment).

The phone being scanned is a Nokia 6126 Type RM-126.

[jdb2 (jonathanbusby)]

I can confirm this behavior with a Kensington USB 2.0 Bluetooth 2.0 EDR dongle ( model# K33348B , Chip: Broadcom Corp 2 BCM92045B3 ROM ) : a segfault after pressing "Scan" every time "Discover Remote Services" is checked.

Recently not only did KBlueMon segfault or lock up, but invariably my whole system would lock up, with the exception that in some cases the mouse pointer would still be active -- I could still gain access to a shell prompt using the Magic SysRq key by putting the keyboard into RAW mode and tapping Alt-1. For some reason, after some recent updates, this behavior stopped with the reproducible segfault described in the first sentence taking its place. Sorry that I can't be more specific concerning the updates. :/

Also, I have attached the output of dmesg, lspci, uname, version, and lsusb. ( with each conforming to the same criteria required by a kernel bug report ) I captured output from the above commands 3 times : Before insertion of the Bluetooth USB key, After the insertion, After the crash. Each of the 3 outputs from the above commands has been saved in a Bzipped TAR file corresponding to the name of the command. Also, I've included the backtrace of the crash, which follows. My system configuration is included at the end of this comment. ( I know that including 3 copies of the output of uname and version is redundant, but I have a shell script to do the logging and taring, and I'm lazy. ;) )

--------------------------------------------

kbluemon.kcrash :

(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
[Thread debugging using libthread_db enabled]
[New Thread 0xb67ca6c0 (LWP 9230)]
[KCrash handler]
#6 0xb6fbe052 in QShared::ref (this=0x53e58955) at ../include/qshared.h:52
#7 0xb73b6367 in QString::operator= (this=0x6530d00c, s=@0xb70b0076)
    at tools/qstring.cpp:1596
#8 0x080525aa in ?? ()
#9 0x080525f0 in ?? ()
#10 0x08051c91 in ?? ()
#11 0x08052098 in ?? ()
#12 0xb709a704 in QObject::activate_signal (this=0x80e9a88, clist=0x8091b40,
    o=0xbfcd73fc) at kernel/qobject.cpp:2359
#13 0xb7f27ae4 in KBluetooth::Adapter::remoteDeviceFound ()
   from /usr/lib/libkbluetooth.so.0
#14 0xb7f2ad41 in KBluetooth::Adapter::filterFunctionAd ()
   from /usr/lib/libkbluetooth.so.0
#15 0xb7ee0a37 in dbus_connection_dispatch () from /usr/lib/libdbus-1.so.3
#16 0xb7eb9893 in DBusQt::Connection::dispatchRead ()
   from /usr/lib/libdbus-qt-1.so.1
#17 0xb7eba147 in DBusQt::Connection::qt_invoke ()
   from /usr/lib/libdbus-qt-1.so.1
#18 0xb709a704 in QObject::activate_signal (this=0x80e9ce0, clist=0x80ea138,
    o=0xbfcd7638) at kernel/qobject.cpp:2359
#19 0xb709b1e9 in QObject::activate_signal (this=0x80e9ce0, signal=2)
    at kernel/qobject.cpp:2328
#20 0xb7ebab29 in DBusQt::Internal::Integrator::readReady ()
   from /usr/lib/libdbus-qt-1.so.1
#21 0xb7ebac0f in DBusQt::Internal::Integrator::slotRead ()
   from /usr/lib/libdbus-qt-1.so.1
#22 0xb7ebac8a in DBusQt::Internal::Integrator::qt_invoke ()
   from /usr/lib/libdbus-qt-1.so.1
#23 0xb709a704 in QObject::activate_signal (this=0x80e8728, clist=0x80e9ff0,
    o=0xbfcd7770) at kernel/q...

[jdb2 (jonathanbusby)]

Forgot to mention the device being scanned : a Samsung Blackjack II cell phone.

[jdb2 (jonathanbusby)]

I compiled kdebluetooth ( which includes kbluemon ) from the latest svn snapshot, with all the debugging symbols enabled.

Here's the crash backtrace :

[Thread debugging using libthread_db enabled]
[New Thread 0xb675c6c0 (LWP 26800)]
[KCrash handler]
#6 0x08054c2d in QValueVector<QString>::detach (this=0x6f008e)
    at /usr/share/qt3/include/qvaluevector.h:482
#7 0x08054c8d in QValueVector<QString>::at (this=0x6f008e, i=0, ok=0x0)
    at /usr/share/qt3/include/qvaluevector.h:345
#8 0x0805207d in Monitor::newdev (this=0xbff38724, name=@0x81500c0,
    dev_class=5898764, rssi=44) at monitor.cpp:150
#9 0x08052882 in Monitor::qt_invoke (this=0xbff38724, _id=53, _o=0xbff37df0)
    at monitor.moc:123
#10 0xb702c704 in QObject::activate_signal (this=0x80edab8, clist=0x809c790,
    o=0xbff37df0) at kernel/qobject.cpp:2359
#11 0xb7ef96bd in KBluetooth::Adapter::remoteDeviceFound (this=0x80edab8,
    t0=@0xbff37ee4, t1=5898764, t2=-62) at adapter.moc:324
#12 0xb7efa17a in KBluetooth::Adapter::filterFunctionAd (msg=0x80eda40)
    at adapter.cpp:556
#13 0xb7e8ea37 in dbus_connection_dispatch () from /usr/lib/libdbus-1.so.3
#14 0xb7e67893 in DBusQt::Connection::dispatchRead ()
   from /usr/lib/libdbus-qt-1.so.1
#15 0xb7e68147 in DBusQt::Connection::qt_invoke ()
   from /usr/lib/libdbus-qt-1.so.1
#16 0xb702c704 in QObject::activate_signal (this=0x80ef028, clist=0x80ef428,
    o=0xbff38038) at kernel/qobject.cpp:2359
#17 0xb702d1e9 in QObject::activate_signal (this=0x80ef028, signal=2)
    at kernel/qobject.cpp:2328
#18 0xb7e68b29 in DBusQt::Internal::Integrator::readReady ()
   from /usr/lib/libdbus-qt-1.so.1
#19 0xb7e68c0f in DBusQt::Internal::Integrator::slotRead ()
   from /usr/lib/libdbus-qt-1.so.1
#20 0xb7e68c8a in DBusQt::Internal::Integrator::qt_invoke ()
   from /usr/lib/libdbus-qt-1.so.1
#21 0xb702c704 in QObject::activate_signal (this=0x80ece60, clist=0x80ef2a8,
    o=0xbff38170) at kernel/qobject.cpp:2359
#22 0xb702d051 in QObject::activate_signal (this=0x80ece60, signal=2,
    param=12) at kernel/qobject.cpp:2452
#23 0xb73bcb99 in QSocketNotifier::activated (this=0x80ece60, t0=12)
    at .moc/debug-shared-mt/moc_qsocketnotifier.cpp:85
#24 0xb704e766 in QSocketNotifier::event (this=0x80ece60, e=0xbff38480)
    at kernel/qsocketnotifier.cpp:261
#25 0xb6fc0c36 in QApplication::internalNotify (this=0xbff38940,
    receiver=0x80ece60, e=0xbff38480) at kernel/qapplication.cpp:2638
#26 0xb6fc2a5f in QApplication::notify (this=0xbff38940, receiver=0x80ece60,
    e=0xbff38480) at kernel/qapplication.cpp:2361
#27 0xb77819b2 in KApplication::notify (this=0xbff38940, receiver=0x80ece60,
    event=0xbff38480)
    at /build/buildd/kdelibs-3.5.10/./kdecore/kapplication.cpp:550
#28 0xb6f5128d in QApplication::sendEvent (receiver=0x80ece60,
    event=0xbff38480) at ../include/qapplication.h:523
#29 0xb6fb2b4a in QEventLoop::activateSocketNotifiers (this=0x8096b88)
    at kernel/qeventloop_unix.cpp:581
#30 0xb6f66630 in QEventLoop::processEvents (this=0x8096b88, flags=4)
    at kernel/qeventloop_x11.cpp:386
#31 0xb6fdbf90 in QEventLoop::enterLoop (this=0x8096b88)
    at kernel/qeventloop.cpp:201
#32 0xb6fc275d in QApplication::enter_loop (this=0xb...