Application: krita (2.6.3)
KDE Platform Version: 4.10.2
Qt Version: 4.8.4
Operating System: Linux 3.8.0-19-generic x86_64
Distribution: Ubuntu 13.04

-- Information about the crash:
As above, I had just loaded a 16bit per channel compressed PNG produced by Fotoxx from several blended HDR exposures. A small part of the image exhibited ghosting, possibly as a result of the exposures being taken with a handheld camera through the window of a train travelling at about 70mph. Not being terribly familiar with Krita, I settled on the "Select by brush" tool to make the selection. On three repeatable attempts, the tool initially worked, but either caused a crash before finishing the selection, or when trying to operate on the new selection. I'm afraid I was using the proprietary Nvidia drivers and these seem to feature heavily in the backtrace, however I had disabled OpenGL support in Krita previously due to unusably slow performance with it enabled. Please let me know if I can provide any more information.

The crash can be reproduced sometimes.

-- Backtrace:
Application: Krita (krita), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f40431f17c0 (LWP 10111))]

Thread 7 (Thread 0x7f4027981700 (LWP 10112)):
#0  0x00007f403b7ee0ca in __GI___pthread_mutex_lock (mutex=0xac53e0) at pthread_mutex_lock.c:116
#1  0x00007f403b3585c1 in g_mutex_lock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f403b318abb in g_main_context_query () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f403b31914c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f403b3196ba in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007f402f2944f6 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#6  0x00007f403b33ceb5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#7  0x00007f40357443b4 in ?? () from /usr/lib/nvidia-310-updates/libGL.so.1
#8  0x00007f403b7ebf8e in start_thread (arg=0x7f4027981700) at pthread_create.c:311
#9  0x00007f404274ae1d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113

Thread 6 (Thread 0x7f40156bc700 (LWP 10113)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f404066e14b in wait (time=18446744073709551615, this=0x5926240) at thread/qwaitcondition_unix.cpp:86
#2  QWaitCondition::wait (this=<optimized out>, mutex=0x59261f0, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:158
#3  0x00007f404066a067 in QSemaphore::acquire (this=this@entry=0x5925f40, n=n@entry=1) at thread/qsemaphore.cpp:144
#4  0x00007f401d7e33ee in KisTileDataPooler::waitForWork (this=this@entry=0x5925f30) at /build/buildd/calligra-2.6.3/krita/image/tiles3/kis_tile_data_pooler.cc:162
#5  0x00007f401d7e379b in KisTileDataPooler::run (this=0x5925f30) at /build/buildd/calligra-2.6.3/krita/image/tiles3/kis_tile_data_pooler.cc:184
#6  0x00007f404066dbec in QThreadPrivate::start (arg=0x5925f30) at thread/qthread_unix.cpp:338
#7  0x00007f40357443b4 in ?? () from /usr/lib/nvidia-310-updates/libGL.so.1
#8  0x00007f403b7ebf8e in start_thread (arg=0x7f40156bc700) at pthread_create.c:311
#9  0x00007f404274ae1d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113

Thread 5 (Thread 0x7f4014ebb700 (LWP 10114)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f404066e14b in wait (time=18446744073709551615, this=0x59265d0) at thread/qwaitcondition_unix.cpp:86
#2  QWaitCondition::wait (this=<optimized out>, mutex=0x5926580, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:158
#3  0x00007f404066a438 in QSemaphore::tryAcquire (this=0x59262b0, n=n@entry=1, timeout=timeout@entry=-1) at thread/qsemaphore.cpp:221
#4  0x00007f401d800f13 in KisTileDataSwapper::waitForWork (this=this@entry=0x5925f68) at /build/buildd/calligra-2.6.3/krita/image/tiles3/swap/kis_tile_data_swapper.cpp:86
#5  0x00007f401d80120a in KisTileDataSwapper::run (this=0x5925f68) at /build/buildd/calligra-2.6.3/krita/image/tiles3/swap/kis_tile_data_swapper.cpp:92
#6  0x00007f404066dbec in QThreadPrivate::start (arg=0x5925f68) at thread/qthread_unix.cpp:338
#7  0x00007f40357443b4 in ?? () from /usr/lib/nvidia-310-updates/libGL.so.1
#8  0x00007f403b7ebf8e in start_thread (arg=0x7f4014ebb700) at pthread_create.c:311
#9  0x00007f404274ae1d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113

Thread 4 (Thread 0x7f400effd700 (LWP 10121)):
#0  0x00007f404079b61a in QEventDispatcherUNIXPrivate::doSelect (this=this@entry=0x7f4000000940, flags=..., timeout=0x0) at kernel/qeventdispatcher_unix.cpp:211
#1  0x00007f404079bc82 in QEventDispatcherUNIX::processEvents (this=0x7f4000000920, flags=...) at kernel/qeventdispatcher_unix.cpp:937
#2  0x00007f404076938f in QEventLoop::processEvents (this=this@entry=0x7f400effccd0, flags=...) at kernel/qeventloop.cpp:149
#3  0x00007f4040769618 in QEventLoop::exec (this=this@entry=0x7f400effccd0, flags=...) at kernel/qeventloop.cpp:204
#4  0x00007f404066b410 in QThread::exec (this=this@entry=0x5e2c8b0) at thread/qthread.cpp:542
#5  0x00007f404074aedf in QInotifyFileSystemWatcherEngine::run (this=0x5e2c8b0) at io/qfilesystemwatcher_inotify.cpp:256
#6  0x00007f404066dbec in QThreadPrivate::start (arg=0x5e2c8b0) at thread/qthread_unix.cpp:338
#7  0x00007f40357443b4 in ?? () from /usr/lib/nvidia-310-updates/libGL.so.1
#8  0x00007f403b7ebf8e in start_thread (arg=0x7f400effd700) at pthread_create.c:311
#9  0x00007f404274ae1d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113

Thread 3 (Thread 0x7f400f7fe700 (LWP 10148)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f404066e14b in wait (time=18446744073709551615, this=0x9d0e650) at thread/qwaitcondition_unix.cpp:86
#2  QWaitCondition::wait (this=this@entry=0x9d0e1d8, mutex=mutex@entry=0x9d0e1d0, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:158
#3  0x00007f4041644636 in QFileInfoGatherer::run (this=0x9d0e1c0) at dialogs/qfileinfogatherer.cpp:214
#4  0x00007f404066dbec in QThreadPrivate::start (arg=0x9d0e1c0) at thread/qthread_unix.cpp:338
#5  0x00007f40357443b4 in ?? () from /usr/lib/nvidia-310-updates/libGL.so.1
#6  0x00007f403b7ebf8e in start_thread (arg=0x7f400f7fe700) at pthread_create.c:311
#7  0x00007f404274ae1d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113

Thread 2 (Thread 0x7f3ff8a40700 (LWP 10149)):
#0  0x00007f4042743233 in select () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f40407964f3 in qt_safe_select (nfds=41, fdread=0x7f3fd8000af8, fdwrite=0x7f3fd8000d90, fdexcept=0x7f3fd8001028, orig_timeout=0x0) at kernel/qcore_unix.cpp:83
#2  0x00007f404079b499 in QEventDispatcherUNIXPrivate::doSelect (this=this@entry=0x7f3fd8000940, flags=..., timeout=0x0) at kernel/qeventdispatcher_unix.cpp:223
#3  0x00007f404079bc82 in QEventDispatcherUNIX::processEvents (this=0x7f3fd8000920, flags=...) at kernel/qeventdispatcher_unix.cpp:937
#4  0x00007f404076938f in QEventLoop::processEvents (this=this@entry=0x7f3ff8a3fcd0, flags=...) at kernel/qeventloop.cpp:149
#5  0x00007f4040769618 in QEventLoop::exec (this=this@entry=0x7f3ff8a3fcd0, flags=...) at kernel/qeventloop.cpp:204
#6  0x00007f404066b410 in QThread::exec (this=this@entry=0x9d0e860) at thread/qthread.cpp:542
#7  0x00007f404074aedf in QInotifyFileSystemWatcherEngine::run (this=0x9d0e860) at io/qfilesystemwatcher_inotify.cpp:256
#8  0x00007f404066dbec in QThreadPrivate::start (arg=0x9d0e860) at thread/qthread_unix.cpp:338
#9  0x00007f40357443b4 in ?? () from /usr/lib/nvidia-310-updates/libGL.so.1
#10 0x00007f403b7ebf8e in start_thread (arg=0x7f3ff8a40700) at pthread_create.c:311
#11 0x00007f404274ae1d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113

Thread 1 (Thread 0x7f40431f17c0 (LWP 10111)):
[KCrash Handler]
#6  0x00007f40400bf834 in KParts::ReadWritePart::isModified (this=0x5c8e230) at ../../kparts/part.cpp:1031
#7  0x00007f40422f81e0 in KoDocument::isModified (this=this@entry=0x5c8e1f0) at /build/buildd/calligra-2.6.3/libs/main/KoDocument.cpp:556
#8  0x00007f40422fd7cd in KoDocument::slotAutoSave (this=0x5c8e1f0) at /build/buildd/calligra-2.6.3/libs/main/KoDocument.cpp:481
#9  0x00007f40422fdb05 in KoDocument::qt_static_metacall (_o=0x5c8e230, _c=QMetaObject::InvokeMetaMethod, _id=1, _a=0x7fffd2422890) at /build/buildd/calligra-2.6.3/obj-x86_64-linux-gnu/libs/main/KoDocument.moc:97
#10 0x00007f404077f0ef in QMetaObject::activate (sender=0x5c8d410, m=<optimized out>, local_signal_index=<optimized out>, argv=0x0) at kernel/qobject.cpp:3539
#11 0x00007f40407843ec in QObject::event (this=0x5c8d410, e=<optimized out>) at kernel/qobject.cpp:1156
#12 0x00007f40411538ec in QApplicationPrivate::notify_helper (this=this@entry=0x8da880, receiver=receiver@entry=0x5c8d410, e=e@entry=0x7fffd2422f90) at kernel/qapplication.cpp:4567
#13 0x00007f404115625b in QApplication::notify (this=0x7fffd2423390, receiver=receiver@entry=0x5c8d410, e=e@entry=0x7fffd2422f90) at kernel/qapplication.cpp:4428
#14 0x00007f40422efd98 in KoApplication::notify (this=<optimized out>, receiver=0x5c8d410, event=0x7fffd2422f90) at /build/buildd/calligra-2.6.3/libs/main/KoApplication.cpp:528
#15 0x00007f404076a63e in QCoreApplication::notifyInternal (this=0x7fffd2423390, receiver=0x5c8d410, event=event@entry=0x7fffd2422f90) at kernel/qcoreapplication.cpp:946
#16 0x00007f404079bb72 in sendEvent (event=0x7fffd2422f90, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#17 QTimerInfoList::activateTimers (this=0x8dbf58) at kernel/qeventdispatcher_unix.cpp:622
#18 0x00007f404079bbd0 in QEventDispatcherUNIX::activateTimers (this=this@entry=0x7fd440) at kernel/qeventdispatcher_unix.cpp:879
#19 0x00007f404079bd28 in QEventDispatcherUNIX::processEvents (this=this@entry=0x7fd440, flags=...) at kernel/qeventdispatcher_unix.cpp:941
#20 0x00007f40411f9b9f in QEventDispatcherX11::processEvents (this=0x7fd440, flags=...) at kernel/qeventdispatcher_x11.cpp:152
#21 0x00007f404076938f in QEventLoop::processEvents (this=this@entry=0x7fffd24232e0, flags=...) at kernel/qeventloop.cpp:149
#22 0x00007f4040769618 in QEventLoop::exec (this=this@entry=0x7fffd24232e0, flags=...) at kernel/qeventloop.cpp:204
#23 0x00007f404076ecf6 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1218
#24 0x00007f4041151ffc in QApplication::exec () at kernel/qapplication.cpp:3828
#25 0x00007f4042bff312 in kdemain (argc=<optimized out>, argv=<optimized out>) at /build/buildd/calligra-2.6.3/krita/main.cc:114
#26 0x00007f4042672ea5 in __libc_start_main (main=0x4006d0 <main(int, char**)>, argc=1, ubp_av=0x7fffd24234a8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffd2423498) at libc-start.c:260
#27 0x0000000000400701 in _start ()

Reported using DrKonqi