Re: 求助一个Crash Dump的INVALID_POINTER_READ问题

C/C++本地代码调试

求助一个Crash Dump的INVALID_POINTER_READ问题

saviola 2016-06-02, 19:33 下午
各位高手和老师们好！

近期遇到个无法解释的问题，程序Crash了，windbg了一下Dump，用.ecxr得到了exception状态时的指令。但是，它执行的指令不该触发异常啊，请看下这怎么解释？

0:005> !analyze -v

FAULTING_IP:
ProgramName!FAsyncTask<FSceneRenderer::FAsyncVisibilityCull>::FinishThreadedWork+3
0199ac63 83bfb003000000 cmp     dword ptr [edi+3B0h],0

EXCEPTION_RECORD: ffffffff -- (.exr 0xffffffffffffffff)
ExceptionAddress: 0199ac63 (ProgramName!FAsyncTask<FSceneRenderer::FAsyncVisibilityCull>::FinishThreadedWork+0x00000003)
   ExceptionCode: c0000005 (Access violation)
ExceptionFlags: 00000000
NumberParameters: 2
   Parameter[0]: 00000000
   Parameter[1]: abe904dc
Attempt to read from address abe904dc

DEFAULT_BUCKET_ID: INVALID_POINTER_READ

0:005> .ecxr
eax=00000000 ebx=0007781f ecx=abe9012c edx=00000002 esi=007cfd20 edi=abe9012c
eip=0199ac63 esp=077efcc4 ebp=077efce8 iopl=0         nv up ei pl zr na pe cy
cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b             efl=00010247
ProgramName!FAsyncTask<FSceneRenderer::FAsyncVisibilityCull>::FinishThreadedWork+0x3:
0199ac63 83bfb003000000 cmp     dword ptr [edi+3B0h],0 ds:002b:abe904dc=00000000

0:005> !address abe904dc
ProcessParametrs 00bd13e8 in range 00bd0000 00cd0000
Environment 00bd07f0 in range 00bd0000 00cd0000
    abe90000 : abe90000 - 0001e000
                    Type     00020000 MEM_PRIVATE
                    Protect 00000004 PAGE_READWRITE
                    State    00001000 MEM_COMMIT
                    Usage    RegionUsageIsVAD

0:005> dd abe904dc-20h L10
abe904bc 00000000 00000001 00000001 00000028
abe904cc 00000000 00000000 00000000 00000000
abe904dc 00000000 00000000 02b041c4 abe90058
abe904ec 7f7fffff 00000025 00000008 55804600

这块内存完全是可以被读到内容的呀，是个正常的READWRITE Page，哪怕是指针指坏了不该读那儿，但不管怎样是能读到的呀！为什么异常了？

背景：这是个32位程序，跑在64位Windows上时偶发Crash时的Dump

好迷茫，求指教。万分感谢！

Re: 求助一个Crash Dump的INVALID_POINTER_READ问题

HiJack 2016-08-14, 16:03 下午
你确认这个地址可读？edi+3B0h