QT （C++）定位内存越界（踩内存）问题

同事写的QT （C++）运行就崩溃，简单扫了一下代码，估计是内存越界了。但是第一眼没看出来。也懒得一行一行看，所以就借助AddressSanitizer（俗称阿三。。。。）这个软件找一下，

我们是在Ubuntu下面所以先安装2个库

apt install libasan8
apt install llvm

然后去QT的 .PRO文件加两个编译选项

QMAKE_CXXFLAGS += -fsanitize=address -fno-omit-frame-pointer -O1
QMAKE_LFLAGS += -fsanitize=address  

然后编译

运行你的程序    ./Example  我的叫这个名字

=================================================================
==16320==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7fffe4bff800 at pc 0x555555794e15 bp 0x7fffffffcbd0 sp 0x7fffffffcbc0
WRITE of size 1 at 0x7fffe4bff800 thread T0
    #0 0x555555794e14 in WindowPlayBackGrayscaleImage::SetPlaybackData() ../../NewCode/Dialog/Components/windowplaybackgrayscaleimage.cpp:348
    #1 0x5555557990ff in WindowPlayBackGrayscaleImage::RecieveData(int, unsigned char*, int) ../../NewCode/Dialog/Components/windowplaybackgrayscaleimage.cpp:288
    #2 0x555555863bc7 in MainWindow::GetBackPlayDataAndSend(int, int) ../../NewCode/Dialog/windowmain.cpp:2079
    #3 0x555555863d75 in MainWindow::BackplayRefreshDataTimeoutSlot() ../../NewCode/Dialog/windowmain.cpp:2063
    #4 0x555555a0d913 in MainWindow::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) /mnt/hgfs/VCode/YiTiJi/Code/integratedmachine/一体机软件/build-Example-Desktop_Qt_5_15_2_GCC_64bit-Debug/moc_windowmain.cpp:344
    #5 0x7ffff32d5dde in void doActivate(QObject*, int, void**) kernel/qobject.cpp:3898
    #6 0x7ffff32daa56 in QTimer::timeout(QTimer::QPrivateSignal) .moc/moc_qtimer.cpp:205
    #7 0x7ffff32dad27 in QTimer::timerEvent(QTimerEvent*) kernel/qtimer.cpp:257
    #8 0x7ffff32ccd5a in QObject::event(QEvent*) kernel/qobject.cpp:1336
    #9 0x7ffff476343b in QApplicationPrivate::notify_helper(QObject*, QEvent*) kernel/qapplication.cpp:3632
    #10 0x7ffff4769f1f in QApplication::notify(QObject*, QEvent*) kernel/qapplication.cpp:3378
    #11 0x7ffff329d807 in QCoreApplication::notifyInternal2(QObject*, QEvent*) kernel/qcoreapplication.cpp:1063
    #12 0x7ffff32f8688 in QTimerInfoList::activateTimers() kernel/qtimerinfo_unix.cpp:643
    #13 0x7ffff32f8e98 in timerSourceDispatch kernel/qeventdispatcher_glib.cpp:183
    #14 0x7ffff32f8e98 in idleTimerSourceDispatch kernel/qeventdispatcher_glib.cpp:230
    #15 0x7ffff4f1bd3a in g_main_context_dispatch (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x55d3a)
    #16 0x7ffff4f71257  (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0xab257)
    #17 0x7ffff4f193e2 in g_main_context_iteration (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x533e2)
    #18 0x7ffff32f91cb in QEventDispatcherGlib::processEvents(QFlags) kernel/qeventdispatcher_glib.cpp:423
    #19 0x7ffff329c219 in QEventLoop::exec(QFlags) kernel/qeventloop.cpp:232
    #20 0x7ffff32a51d2 in QCoreApplication::exec() kernel/qcoreapplication.cpp:1371
    #21 0x555555904693 in main ../../NewCode/main.cpp:22
    #22 0x7ffff2829d8f in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
    #23 0x7ffff2829e3f in __libc_start_main_impl ../csu/libc-start.c:392
    #24 0x5555555dfa34 in _start (/mnt/hgfs/VCode/YiTiJi/Code/integratedmachine/一体机软件/build-Example-Desktop_Qt_5_15_2_GCC_64bit-Debug/Example+0x8ba34)

0x7fffe4bff800 is located 0 bytes to the right of 1536000-byte region [0x7fffe4a88800,0x7fffe4bff800)
allocated by thread T0 here:
    #0 0x7ffff74b6357 in operator new[](unsigned long) ../../../../src/libsanitizer/asan/asan_new_delete.cpp:102
    #1 0x555555792856 in WindowPlayBackGrayscaleImage::initFile(ZoroyRadarBackplayLineInfo) ../../NewCode/Dialog/Components/windowplaybackgrayscaleimage.cpp:97
    #2 0x555555876344 in MainWindow::OpenNewLineSlot(LineFileInfo) ../../NewCode/Dialog/windowmain.cpp:730
    #3 0x555555a0d50d in MainWindow::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) /mnt/hgfs/VCode/YiTiJi/Code/integratedmachine/一体机软件/build-Example-Desktop_Qt_5_15_2_GCC_64bit-Debug/moc_windowmain.cpp:308
    #4 0x7ffff32d5dde in void doActivate(QObject*, int, void**) kernel/qobject.cpp:3898
    #5 0x555555a05901 in LineManager::signal_openLineConfirm(LineFileInfo) /mnt/hgfs/VCode/YiTiJi/Code/integratedmachine/一体机软件/build-Example-Desktop_Qt_5_15_2_GCC_64bit-Debug/moc_WindowLineManager.cpp:562
    #6 0x555555803033 in LineManager::OpenLineProcess() ../../NewCode/Dialog/Project/WindowLineManager.cpp:863
    #7 0x555555a05ee8 in LineManager::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) /mnt/hgfs/VCode/YiTiJi/Code/integratedmachine/一体机软件/build-Example-Desktop_Qt_5_15_2_GCC_64bit-Debug/moc_WindowLineManager.cpp:493
    #8 0x7ffff32d5dde in void doActivate(QObject*, int, void**) kernel/qobject.cpp:3898
    #9 0x555555a057cf in OpenAndDeleteLineWindow::signal_openLine() /mnt/hgfs/VCode/YiTiJi/Code/integratedmachine/一体机软件/build-Example-Desktop_Qt_5_15_2_GCC_64bit-Debug/moc_WindowLineManager.cpp:395
    #10 0x5555557f41f9 in OpenAndDeleteLineWindow::OnBtnOpenConfirmClicked() ../../NewCode/Dialog/Project/WindowLineManager.cpp:474
    #11 0x555555a05b10 in OpenAndDeleteLineWindow::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) /mnt/hgfs/VCode/YiTiJi/Code/integratedmachine/一体机软件/build-Example-Desktop_Qt_5_15_2_GCC_64bit-Debug/moc_WindowLineManager.cpp:308
    #12 0x7ffff32d5dde in void doActivate(QObject*, int, void**) kernel/qobject.cpp:3898
    #13 0x7ffff484eba1 in QAbstractButton::clicked(bool) .moc/moc_qabstractbutton.cpp:308

SUMMARY: AddressSanitizer: heap-buffer-overflow ../../NewCode/Dialog/Components/windowplaybackgrayscaleimage.cpp:348 in WindowPlayBackGrayscaleImage::SetPlaybackData()
Shadow bytes around the buggy address:
  0x10007c977eb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10007c977ec0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10007c977ed0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10007c977ee0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10007c977ef0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x10007c977f00:[fa]fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x10007c977f10: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x10007c977f20: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x10007c977f30: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x10007c977f40: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x10007c977f50: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
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
  Shadow gap:              cc
==16320==ABORTING
 

通过观察 发现是 ../../NewCode/Dialog/Components/windowplaybackgrayscaleimage.cpp:348 这行有问题，然后在通过0x7fffe4bff800 is located 0 bytes to the right of 1536000-byte region [0x7fffe4a88800,0x7fffe4bff800) 这句话就彻底明白你是怎么出错的了，很明显是内存越界了。

你要英语不好，实在看不明白 就把这些关键信息放文心一言里面，它能帮你翻译一下