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f4exb / sdrangel

SDR Rx/Tx software for Airspy, Airspy HF+, BladeRF, HackRF, LimeSDR, PlutoSDR, RTL-SDR, SDRplay and FunCube
GNU General Public License v3.0
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AIS: array access out of bounds #2101

Open dforsi opened 1 month ago

dforsi commented 1 month ago

When running sdrangel under ASAN detects a read access error at this line:

AISDemodSink::processOneSample(std::complex<float>&) sdrangel/plugins/channelrx/demodais/aisdemodsink.cpp:20

Printing the variable before line 204 shows that the error is triggered when x is zero, so the code reads from item -1 of the array

qDebug("x %d sampleOffset %d i %d m_rxBufLength %d", x, sampleOffset, i, m_rxBufLength);

I noticed that each time the starting value of x in incremented by 1:

2024-05-05 23:36:22.514 (D) x 113 sampleOffset -1 i 0 m_rxBufLength 6432
2024-05-05 23:36:22.516 (D) x 114 sampleOffset -1 i 0 m_rxBufLength 6432
2024-05-05 23:36:22.517 (D) x 115 sampleOffset -1 i 0 m_rxBufLength 6432
...

Here is the full output of the error:

READ of size 4 at 0x52b00028b1fc thread T27 (QThread)
    #0 0x7fcefc35e7ec in AISDemodSink::processOneSample(std::complex<float>&) sdrangel/plugins/channelrx/demodais/aisdemodsink.cpp:204
    #1 0x7fcefc35d9fa in AISDemodSink::feed(__gnu_cxx::__normal_iterator<Sample const*, std::vector<Sample, std::allocator<Sample> > > const&, __gnu_cxx::__normal_iterator<Sample const*, std::vector<Sample, std::allocator<Sample> > > const&) sdrangel/plugins/channelrx/demodais/aisdemodsink.cpp:112
    #2 0x7fcf28e88cec in DownChannelizer::feed(__gnu_cxx::__normal_iterator<Sample const*, std::vector<Sample, std::allocator<Sample> > > const&, __gnu_cxx::__normal_iterator<Sample const*, std::vector<Sample, std::allocator<Sample> > > const&) sdrangel/sdrbase/dsp/downchannelizer.cpp:57
    #3 0x7fcefc358766 in AISDemodBaseband::handleData() sdrangel/plugins/channelrx/demodais/aisdemodbaseband.cpp:107
    #4 0x7fcefc359c42 in QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, void (AISDemodBaseband::*)()>::call(void (AISDemodBaseband::*)(), AISDemodBaseband*, void**) /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:152
    #5 0x7fcefc359a7c in void QtPrivate::FunctionPointer<void (AISDemodBaseband::*)()>::call<QtPrivate::List<>, void>(void (AISDemodBaseband::*)(), AISDemodBaseband*, void**) /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:185
    #6 0x7fcefc359917 in QtPrivate::QSlotObject<void (AISDemodBaseband::*)(), QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*) /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:418
    #7 0x7fcf262f993f in QObject::event(QEvent*) (/lib/x86_64-linux-gnu/libQt5Core.so.5+0x2f993f) (BuildId: ed2abb344a128279a866aa6c4a79f3fa5c87c59e)
    #8 0x7fcf26f62f31 in QApplicationPrivate::notify_helper(QObject*, QEvent*) (/lib/x86_64-linux-gnu/libQt5Widgets.so.5+0x162f31) (BuildId: dfefd27f084c0dd066215fc79825fceae604f481)
    #9 0x7fcf262cc747 in QCoreApplication::notifyInternal2(QObject*, QEvent*) (/lib/x86_64-linux-gnu/libQt5Core.so.5+0x2cc747) (BuildId: ed2abb344a128279a866aa6c4a79f3fa5c87c59e)
    #10 0x7fcf262cfe50 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (/lib/x86_64-linux-gnu/libQt5Core.so.5+0x2cfe50) (BuildId: ed2abb344a128279a866aa6c4a79f3fa5c87c59e)
    #11 0x7fcf26328696  (/lib/x86_64-linux-gnu/libQt5Core.so.5+0x328696) (BuildId: ed2abb344a128279a866aa6c4a79f3fa5c87c59e)
    #12 0x7fcf253111f3  (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x571f3) (BuildId: 15cc0c863407714c5f1c645396cc190177fa08c1)
    #13 0x7fcf25314316  (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x5a316) (BuildId: 15cc0c863407714c5f1c645396cc190177fa08c1)
    #14 0x7fcf2531492f in g_main_context_iteration (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x5a92f) (BuildId: 15cc0c863407714c5f1c645396cc190177fa08c1)
    #15 0x7fcf26327d49 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (/lib/x86_64-linux-gnu/libQt5Core.so.5+0x327d49) (BuildId: ed2abb344a128279a866aa6c4a79f3fa5c87c59e)
    #16 0x7fcf262cb0fa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (/lib/x86_64-linux-gnu/libQt5Core.so.5+0x2cb0fa) (BuildId: ed2abb344a128279a866aa6c4a79f3fa5c87c59e)
    #17 0x7fcf260d9c51 in QThread::exec() (/lib/x86_64-linux-gnu/libQt5Core.so.5+0xd9c51) (BuildId: ed2abb344a128279a866aa6c4a79f3fa5c87c59e)
    #18 0x7fcf260daeb0  (/lib/x86_64-linux-gnu/libQt5Core.so.5+0xdaeb0) (BuildId: ed2abb344a128279a866aa6c4a79f3fa5c87c59e)
    #19 0x7fcf2bc5ae55 in asan_thread_start ../../../../src/libsanitizer/asan/asan_interceptors.cpp:234
    #20 0x7fcf25aa645b in start_thread nptl/pthread_create.c:444
    #21 0x7fcf25b26bbb in clone3 ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

0x52b00028b1fc is located 4 bytes before 25728-byte region [0x52b00028b200,0x52b000291680)
allocated by thread T27 (QThread) here:
    #0 0x7fcf2bcf4818 in operator new[](unsigned long) ../../../../src/libsanitizer/asan/asan_new_delete.cpp:98
    #1 0x7fcefc360e7c in AISDemodSink::applySettings(AISDemodSettings const&, bool) sdrangel/plugins/channelrx/demodais/aisdemodsink.cpp:428
    #2 0x7fcefc359240 in AISDemodBaseband::applySettings(AISDemodSettings const&, bool) sdrangel/plugins/channelrx/demodais/aisdemodbaseband.cpp:167
    #3 0x7fcefc358d71 in AISDemodBaseband::handleMessage(Message const&) sdrangel/plugins/channelrx/demodais/aisdemodbaseband.cpp:139
    #4 0x7fcefc358aee in AISDemodBaseband::handleInputMessages() sdrangel/plugins/channelrx/demodais/aisdemodbaseband.cpp:125
    #5 0x7fcefc33d4cb in AISDemodBaseband::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) build-sdrangel-Desktop_qt5-Debug/plugins/channelrx/demodais/demodais_autogen/EWIEGA46WW/moc_aisdemodbaseband.cpp:76
    #6 0x7fcf262f993f in QObject::event(QEvent*) (/lib/x86_64-linux-gnu/libQt5Core.so.5+0x2f993f) (BuildId: ed2abb344a128279a866aa6c4a79f3fa5c87c59e)
    #7 0x7fcf26f62f31 in QApplicationPrivate::notify_helper(QObject*, QEvent*) (/lib/x86_64-linux-gnu/libQt5Widgets.so.5+0x162f31) (BuildId: dfefd27f084c0dd066215fc79825fceae604f481)

Thread T27 (QThread) created by T23 (DSPDeviceSource) here:
    #0 0x7fcf2bcebae1 in pthread_create ../../../../src/libsanitizer/asan/asan_interceptors.cpp:245
    #1 0x7fcf260da974 in QThread::start(QThread::Priority) (/lib/x86_64-linux-gnu/libQt5Core.so.5+0xda974) (BuildId: ed2abb344a128279a866aa6c4a79f3fa5c87c59e)

Thread T23 (DSPDeviceSource) created by T0 here:
    #0 0x7fcf2bcebae1 in pthread_create ../../../../src/libsanitizer/asan/asan_interceptors.cpp:245
    #1 0x7fcf260da974 in QThread::start(QThread::Priority) (/lib/x86_64-linux-gnu/libQt5Core.so.5+0xda974) (BuildId: ed2abb344a128279a866aa6c4a79f3fa5c87c59e)

SUMMARY: AddressSanitizer: heap-buffer-overflow sdrangel/plugins/channelrx/demodais/aisdemodsink.cpp:204 in AISDemodSink::processOneSample(std::complex<float>&)
Shadow bytes around the buggy address:
  0x52b00028af00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x52b00028af80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x52b00028b000: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x52b00028b080: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x52b00028b100: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x52b00028b180: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa[fa]
  0x52b00028b200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x52b00028b280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x52b00028b300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x52b00028b380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x52b00028b400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07 
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
==59311==ABORTING
dforsi commented 1 month ago

The attached zip contains a WAV file that triggers that error in a build with ASAN, while in a build without ASAN a packet gets decoded and saved like this in CSV format:

Date,Time,Data,MMSI,Type,Message,NMEA,Slot,Slots
lun mag 6 2024,20:31:53,,000000000,Unknown message ID (0),"","
",2010,1

I'm going to open a separate issue because trying to load that CSV in sdrangel causes a segfault.

I cut the attached WAV with Audacity and you must add an AIS demodulator at offset +24000 (yes 24) to decode that packet.

IMSI 000000000 +24k - replay_buffer.zip