内存分配/释放错误(非常小的代码)

Question

在运行末尾列出的代码时，我在最后一行FREE(pTcpTable);处得到一个休息，如果我继续这个错误显示:

" netMon.exe中0x7737096E (ntdll.dll)的未处理异常:0xC0000005:访问违反读取位置0x00000009。"

crt0date .c打开，显示如下代码:

void __cdecl __crtExitProcess (
        int status
        )
{
        __crtCorExitProcess(status);
        /*
         * Either mscoree.dll isn't loaded,
         * or CorExitProcess isn't exported from mscoree.dll,
         * or CorExitProcess returned (should never happen).
         * Just call ExitProcess.
         */
        ExitProcess(status);
}

这是代码:

#include <iostream>
#include <WinSock2.h>
#include <IPHlpApi.h>
#include <Ws2tcpip.h>
using namespace std;
#pragma comment(lib, "iphlpapi.lib")
#pragma comment(lib, "ws2_32.lib")
#define MALLOC(x) HeapAlloc(GetProcessHeap(), 0, (x))
#define FREE(x) HeapFree(GetProcessHeap(), 0, (x))
int __cdecl main()
{
    PMIB_TCPTABLE_OWNER_PID pTcpTable;
    DWORD tcpTableSize = 0;
    char szLocalAddr[128];
    struct in_addr IpAddr;
    pTcpTable = (PMIB_TCPTABLE_OWNER_PID)MALLOC(sizeof(MIB_TCPTABLE_OWNER_PID));
    if(pTcpTable == NULL)
        return 1;
    tcpTableSize = sizeof(MIB_TCPTABLE_OWNER_PID);
    if(GetExtendedTcpTable(pTcpTable, &tcpTableSize, FALSE, AF_INET, TCP_TABLE_OWNER_PID_CONNECTIONS, 0) == ERROR_INSUFFICIENT_BUFFER)
    {
        FREE(pTcpTable);
        pTcpTable = (PMIB_TCPTABLE_OWNER_PID)MALLOC(sizeof(tcpTableSize));
        if(pTcpTable == NULL)
            return 1;
    }
    if(GetExtendedTcpTable(pTcpTable, &tcpTableSize, FALSE, AF_INET, TCP_TABLE_OWNER_PID_CONNECTIONS, 0) == NO_ERROR)
    {
        for(DWORD i = 0; i < pTcpTable->dwNumEntries; i++)
        {
            IpAddr.S_un.S_addr = (u_long)pTcpTable->table[i].dwRemoteAddr;
            InetNtop(AF_INET, &IpAddr, szLocalAddr, 128);
        }
    }
    if(pTcpTable != NULL)
        FREE(pTcpTable);
    return 0;
}

我不知道这里有什么问题，它只是简单的内存分配和释放，请在这里帮助我!

Answer 1

我很确定你不想要这个:

    pTcpTable = (PMIB_TCPTABLE_OWNER_PID)MALLOC(sizeof(tcpTableSize));

,而是

    pTcpTable = (PMIB_TCPTABLE_OWNER_PID)MALLOC(tcpTableSize);
    //                                          ^^^^^ sizeof removed.

它几乎肯定会崩溃，因为您覆盖了操作系统在退出时清理堆所必需的其他内容，这就是为什么您访问地址9时会崩溃的原因。

Answer 2

问题就在这里

pTcpTable = (PMIB_TCPTABLE_OWNER_PID)MALLOC(**sizeof**(tcpTableSize));

您需要分配tcpTableSize字节，而不是sizeof(DWORD)