Invalid memory area STR

Posted By: oliver2s

Invalid memory area STR - 05/16/12 15:14

Hi,

I have the following code to get My Documents folder:

Code:

#include <acknex.h>;
#include <windows.h>;

long __stdcall RegOpenKey(long hKey, char* lpSubKey, long phkResult);
#define PRAGMA_API RegOpenKey;advapi32!RegOpenKeyA
long __stdcall RegQueryValueEx(long hKey, char* lpValueName, long lpReserved, long lpType, long  lpData, long lpcbData);
#define PRAGMA_API RegQueryValueEx;advapi32!RegQueryValueExA
long __stdcall RegCloseKey(long hKey);
#define PRAGMA_API RegCloseKey;advapi32!RegCloseKey

var reg_get_STRING(long HKEY, char* KEY, char* VALUE, STRING* *DATA)
{	long regPtr=0, DataType=0, DataLen=999;
	if(RegOpenKey(HKEY, KEY, &regPtr))	return(false);
	if((RegQueryValueEx(regPtr,VALUE,0,&DataType,NULL,&DataLen))||(DataType!=1))
	{	RegCloseKey(regPtr);	return(false);		}
	STRING* tmpStr = str_create("");
	str_cat_num(tmpStr, "\#%.0f", DataLen);
	if(!*DATA)	*DATA = str_create("");
	str_cpy(*DATA, _chr(tmpStr));		str_remove(tmpStr);

	//!!!!=>>following line causes error "invalid memory area STR"<<=!!!!
	RegQueryValueEx(regPtr,VALUE,0,0,_chr(*DATA),&DataLen); 
	
	RegCloseKey(regPtr);	return(true);
}

void getMyDocuments()
{
	STRING* tmpStr = str_create("");
	
	reg_get_STRING(HKEY_CURRENT_USER, "Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Shell Folders", "Personal", tmpStr);
	str_cat(tmpStr, "\\My Game");
	str_cpy(save_dir, tmpStr);
	CreateDirectory(_chr(tmpStr),NULL);
	
	ptr_remove(tmpStr);

	error(save_dir);
}

void main()
{
	warn_level=6;
	getMyDocuments();
}

The code works (almost) well, it gives me the My Documents folder, but I get the error message "invalid memory area STR" in this line:

Code:

RegQueryValueEx(regPtr,VALUE,0,0,_chr(*DATA),&DataLen);

But I don't have any idea what's wrong.

Does anyone have an idea?

Posted By: TechMuc

Re: Invalid memory area STR - 05/16/12 15:56

Hi Oliver,
[edit: this post is full of advertisement, so just copy your code if you don't want to read

]
Okay that's really senseless, but i just have to promote my product here.. With my wonderful perfect editor (liteEdit, for your reference: check this: http://www.opserver.de/ubb7/ubbthreads.php?ubb=showflat&Number=401310#Post401310 ) i was able to REALLY debug your code and check all temporary values.

- enough.

The debugging result was, that the crash didn't happened in your mentioned line but in the str_cat(tmpStr, "\\my Game"); line. Why? Because the string is corrupted (can also be detected by the debugger

), after the RegQueryValueEx instruction.
The string is currupted because you can not give a char* of a string to a WinAPI function. This might (!!) work in very few cases (when the string aquired by str_create is big enough), but most probable will dump, because the other internal struct members of STIRNG (e.g. "length") will be ignored / not mainted.

Use the following code to solve your problem, and use my editor to prevent those problems in future

Code:

#include <acknex.h>;
#include <windows.h>;

long __stdcall RegOpenKey(long hKey, char* lpSubKey, long phkResult);
#define PRAGMA_API RegOpenKey;advapi32!RegOpenKeyA
long __stdcall RegQueryValueEx(long hKey, char* lpValueName, long lpReserved, long lpType, long  lpData, long lpcbData);
#define PRAGMA_API RegQueryValueEx;advapi32!RegQueryValueExA
long __stdcall RegCloseKey(long hKey);
#define PRAGMA_API RegCloseKey;advapi32!RegCloseKey

var reg_get_STRING(long HKEY, char* KEY, char* VALUE, STRING* *DATA)
{	long regPtr=0, DataType=0, DataLen=999;
	char* dwData = 0;
	dwData = (char*)malloc(sizeof(char*)*DataLen);
	memset(dwData,0,DataLen);
	if(RegOpenKey(HKEY, KEY, &regPtr))	return(false);
	if((RegQueryValueEx(regPtr,VALUE,0,&DataType,NULL,&DataLen))||(DataType!=1))
	{	RegCloseKey(regPtr);	return(false);		}
	STRING* tmpStr = str_create("");
	str_cat_num(tmpStr, "\#%.0f", DataLen);
	if(!*DATA)	*DATA = str_create("");
	str_cpy(*DATA, _chr(tmpStr));		str_remove(tmpStr);

	//!!!!=>>following line causes error "invalid memory area STR"<<=!!!!
	RegQueryValueEx(regPtr,VALUE,0,0,dwData,&DataLen); 
	str_cpy(*DATA,dwData);
	free(dwData);
	RegCloseKey(regPtr);	return(true);
}

void getMyDocuments()
{
	STRING* tmpStr = str_create("");
	
	reg_get_STRING(HKEY_CURRENT_USER, "Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Shell Folders", "Personal", tmpStr);
	str_cat(tmpStr, "\\My Game");
	str_cpy(save_dir, tmpStr);
	CreateDirectory(_chr(tmpStr),NULL);
	
	ptr_remove(tmpStr);

	error(save_dir);
}

void main()
{
	warn_level=6;
	getMyDocuments();
}

Posted By: oliver2s

Re: Invalid memory area STR - 05/16/12 16:04

Wow, thank you for the fast answer. Seems it works

And I will try your editor