I'm debugging a software which crashes eventually with one of the following messages:
1. DAMAGE: after normal block (#24729280) at 0x00D710E0
2. Debug Assertion Failed
Program: D:\Soft\Test.exe
File: dbgheap.c
Line: 1017
Expression: _BLOCK_TYPE_IS_VALID(phead->nBlockUse)
This software is really old but changing it now is not an option. It's written on Visual C++ 6.0. We are guessing it's some kind of buffer overflow, so we are trying to find ways to detect where it is happening.
I have found information about PageHeap (which seems to be able to tell me what I want) and GFlags, but it seems I can't make it work.
I created a test program:
char* test;
test = new char[5];
test[5] = 'a';
delete[] test;
which raises an error:
DAMAGE: after normal block (#55) at 0x1671920
Then, I tried attaching PageHeap to it by running:
gflags.exe /p /enable MemoryTest.exe /full
and then rerunning it (both through Visual C++ 6.0 interface and through the windows explorer), which resulted on the same error.
Then I tried to compile the release version, and ran it through the Visual C++ 6.0 interface to get the error:
User breakpoint called from code at 0x7c90120e
And from the windows explorer, I just got the windows dialog asking me to send an error report.
What am I missing?