How could be Readfile permission error be solved?

Well, there's a task to process text file using WinAPI functions and asm nested into C++. When I try to invoke Readfile I'm getting error

Unhandled exception at 0x7692DEB5 (KernelBase.dll) в XXX.exe: 0xC0000005: violation of access rights when writing to 0x00000000

#include "stdafx.h"
#include <Windows.h>
#include <fileapi.h>
#include <string> 
#include <iostream> 
#include <iomanip>

using namespace std;

int main() 
{
    char filename[256] = "text.txt"; //name of file with text
    OFSTRUCT buffer;
    HFILE pfile; 
    DWORD filesize; //size of file
    BYTE * pbuf;

    setlocale(0, "");
__asm
    {
        //File opening
        push OF_READ
        lea eax, buffer
        push eax
        lea eax, filename
        push eax
        call DWORD PTR OpenFile
        cmp eax, -1
        je fopen_error
        mov pfile, eax

        //Getting file size
        push NULL
        push pfile 
        call GetFileSize //executing function which calculates file size, result goes to ax
        mov filesize, eax  //Saving into variable

        //Reserving memory for file reading into buffer
        mov eax, filesize
        inc eax
        push eax
        call malloc
        mov pbuf, eax
        add esp, 4

        //Reading into buffer
        push NULL
        push NULL
        PUSH filesize
        push pbuf
        push pfile
        call ReadFile  // At this point I'm getting an error

It runs nice on my friends PC (Win10 and VS 2017), I'm running on Win7 VS 2017 and I get this exception. Also we tried to launch same exe file with same code and it works good on my friend's PC and doesn't on mine.

Could you please check and tell me where I am wrong?

I think, that must be like this:

char filename[256] = "text.txt"; //name with text
    OFSTRUCT buffer;
    HFILE pfile; 
    DWORD filesize; //file size
    BYTE * pbuf;

    DWORD dwBytesRead; /* error because of absent link */

    setlocale(0, "");
__asm
    {
        //opening file
        push OF_READ
        lea eax, buffer
        push eax
        lea eax, filename
        push eax
        call DWORD PTR OpenFile
        cmp eax, -1
        je fopen_error
        mov pfile, eax

        //Getting full size
        push NULL
        push pfile
        call DWORD PTR GetFileSize //calling function via checking size
        mov filesize, eax  //recording

        //storaging memory for reading
        mov eax, filesize
        inc eax
        push eax
        call DWORD PTR malloc
        mov pbuf, eax
        add esp, 4

       //Reading into buffer
        push NULL
        lea eax,[dwBytesRead]
        push eax
        PUSH filesize
        push pbuf
        push pfile
        call DWORD PTR ReadFile