Memory management routine error - c++

Question

I'm trying to use FP routine, but it doesn't work...Why?
This is my code:
int output = FindPattern(0x0042A000, 0x2000, "\x68\x00\x00\x00\x00\xFF\x76\x08\x89\x46\x44", "x????xxxxxx");
if (output > -1) {
ReadProcessMemory(hProcHandle, (PVOID)address, &value2, sizeof(value2), NULL);
}
Function:
int FindPattern(int start_offset, int size, const char * pattern, const char * mask)
{
int pos = 0;
for (int retAddress = start_offset; retAddress < start_offset + size; retAddress++)
{
if (*(const char*)retAddress == pattern[pos] || mask[pos] == '?')
{
if (mask[pos+1] == '\0')
return retAddress+1;
pos++;
}
else
pos = 0;
}
return -1;
}
I also tried:
DWORD output = FindPattern(hProcHandle, "\x68\x00\x00\x00\x00\xFF\x76\x08\x89\x46\x44", "x????xxxxxx");
bool VerifyAddress(HANDLE hwnd, DWORD dwAddress, char *bMask, char *szMask )
{
PBYTE *pTemp = { 0 };
for ( int i = 0; *szMask; ++szMask, ++bMask, ++i )
{
if ( !ReadProcessMemory( hwnd, reinterpret_cast<LPCVOID>(dwAddress + i), &pTemp, sizeof(pTemp), 0 ) ){
return false;
}
if ( *szMask == 'x' && (char)pTemp != *bMask){
return false;
}
}
return true;
}
DWORD FindPattern(HANDLE hwnd, char* bMask, char *szMask )
{
for ( DWORD dwCurrentAddress = 0x4FFFFFF; dwCurrentAddress < 0x7FFFFFF; dwCurrentAddress++ ){
if ( VerifyAddress( hwnd, dwCurrentAddress, bMask, szMask )) {
return dwCurrentAddress;
}
}
But with these codes I get always
Unhandled exception at 0x01034BB1 in Program.exe: 0xC0000005: Access
violation reading location 0x02343DA2.

Answer 1

This code:
int output = FindPattern(0x0042A000, 0x2000,
indicates that you are using address 0x0042A000 local to your process, so you are iterating over some random addresses in your process which is Undefined Behaviour and ends with exception.
ReadProcessMemory copies specified memory from some other process to your process and stores in in memory buffer you provide in this function call as lpBuffer parameter.