为什么C中的通用链表中存储的数据已损坏

我在C中创建了一个通用链表来存储任何类型的数据。当然，这涉及到使用void指针。我知道代码正常工作，但我的问题可能是由于存储字符数组(即C字符串(的void指针周围的内存管理。可能是因为我对C中的void指针缺乏深入的理解？

出于测试目的，最好使用下面的代码示例来展示我的问题。

slist.h头文件

#ifndef _SLIST_H
#define _SLIST_H
#ifdef __cplusplus
extern "C" {
#endif
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
/* Linked list node data structure for the client program */
typedef struct _listNode {
void *datum;
struct _listNode *next;
} listNode, *plistNode;    
/* Generic pointer to data iterators */
typedef void(*listIterator)(void *);
typedef struct {
unsigned int length;
unsigned int storageSize;
listNode *head;
listNode *tail;
} Slist;
/* Prototype functions */
Slist *createList(const int datasize);
unsigned int destroyList(Slist *pHead);
listNode *insert(Slist *pHead, const void *data);
void iterate(Slist *pHead, listIterator iterator);
#ifdef __cplusplus
}
#endif
#endif

链表源代码-slist.cpp

#include "slist.h"
Slist *createList(const int datasize) {
Slist *pHead;
pHead = (Slist *)malloc(sizeof(Slist));
if (pHead) {
pHead->length = 0;
pHead->storageSize = datasize;
pHead->head = NULL;
pHead->tail = NULL;
}
return pHead;
}
unsigned int destroyList(Slist *pHead) {
unsigned int count = 0;
listNode *tnode;
listNode *cnode = pHead->head;
while (cnode) {
count++;
tnode = cnode;
cnode = cnode->next;
free(tnode->datum);
free(tnode);
}
free(pHead);
pHead = NULL;
return count;
}
listNode *insert(Slist *pHead, const void *data) {
listNode *node = (listNode *)malloc(sizeof(listNode));
if (node) {
node->datum = malloc(pHead->storageSize);
if (node->datum) {
memcpy(node->datum, data, pHead->storageSize);
node->next = NULL;
if (pHead->length > 0) {
pHead->tail->next = node;
pHead->tail = node;
} else {
pHead->head = node;
pHead->tail = node;
}
pHead->length++;
} else {
free(node);
node = NULL;
}
}
return node;
}
void iterate(Slist *pHead, listIterator iterator) {
listNode *node = pHead->head;
while (node) {
iterator(node->datum);
node = node->next;
}
}

主程序

#include "slist.h"
void iterate_string(void *data) {
printf("Address: %p. Data: %s (Ascii char value)n", data, *(char**)data);
}
void testStringList() {
char *buf = NULL;
Slist *list = createList(sizeof(char *));
const char *names[] = { "Toyota", "Mercdes", "Jaguar", "Lotus", "Hyundai", "Volkswagen" };

for (int i = 0; i < (sizeof(names) / sizeof(names[0])); i++) {
int len = strlen(names[i]) + 1;
buf = (char *)malloc(len * sizeof(char));
strcpy_s(buf, len, names[i]);
listNode *ptr = insert(list, &buf);
printf("TEST: Data received after insert -> %s at address %pn", *(char**)ptr->datum, ptr->datum);
free(buf);  <-- NOTE: Is that the issue???? Did I misuse it?
printf("TEST: Data after releasing temp buffer -> %s at address %pnn", *(char**)ptr->datum, ptr->datum);
}
iterate(list, iterate_string);
int killCount = destroyList(list);
printf("nList destroyed after killing %d strings...n", killCount);
}
int main(int argc, char **argv) {
testStringList();
return 0;
}

生成的输出1

TEST: Data received after insert -> Toyota at address 005642F0
TEST: Data after releasing temp buffer -> ннннннннннн at address 005642F0
TEST: Data received after insert -> Mercdes at address 00567A50
TEST: Data after releasing temp buffer -> ннннннннннннu at address 00567A50
TEST: Data received after insert -> Jaguar at address 00567AB8
TEST: Data after releasing temp buffer -> ннннннннннннu at address 00567AB8
TEST: Data received after insert -> Lotus at address 00567B20
TEST: Data after releasing temp buffer -> ннннннннннннu at address 00567B20
TEST: Data received after insert -> Hyundai at address 00567B88
TEST: Data after releasing temp buffer -> ннннннннннннu at address 00567B88
TEST: Data received after insert -> Volkswagen at address 00567BF0
TEST: Data after releasing temp buffer -> ннннннннннннннн at address 00567BF0
Address: 005642F0. Data: ннннннннннннннн (Ascii char value)
Address: 00567A50. Data: ннннннннннннннн (Ascii char value)
Address: 00567AB8. Data: ннннннннннннннн (Ascii char value)
Address: 00567B20. Data: ннннннннннннннн (Ascii char value)
Address: 00567B88. Data: ннннннннннннннн (Ascii char value)
Address: 00567BF0. Data: ннннннннннннннн (Ascii char value)
List destroyed after killing 6 strings...

生成的输出2

TEST: Data received after insert -> Toyota at address 007F3DB0
TEST: Data after releasing temp buffer -> Toyota at address 007F3DB0
TEST: Data received after insert -> Mercdes at address 007F3E18
TEST: Data after releasing temp buffer -> Mercdes at address 007F3E18
TEST: Data received after insert -> Jaguar at address 007F78D8
TEST: Data after releasing temp buffer -> Jaguar at address 007F78D8
TEST: Data received after insert -> Lotus at address 007F7978
TEST: Data after releasing temp buffer -> Lotus at address 007F7978
TEST: Data received after insert -> Hyundai at address 007F7A18
TEST: Data after releasing temp buffer -> Hyundai at address 007F7A18
TEST: Data received after insert -> Volkswagen at address 007F04D0
TEST: Data after releasing temp buffer -> Volkswagen at address 007F04D0
Address: 007F3DB0. Data: Toyota (Ascii char value)
Address: 007F3E18. Data: Mercdes (Ascii char value)
Address: 007F78D8. Data: Jaguar (Ascii char value)
Address: 007F7978. Data: Lotus (Ascii char value)
Address: 007F7A18. Data: Hyundai (Ascii char value)
Address: 007F04D0. Data: Volkswagen (Ascii char value)
List destroyed after killing 6 strings...

正如您所看到的，我想要字符串的动态存储，并通过void指针存储在通用链表中。为了进行测试，buf变量只是从硬编码数组中动态复制字符串，然后存储在列表中。一旦复制了每个数据，buf就会被释放，然后重新分配给下一个数据，以此类推

但结果并不是我所希望的(见输出1(。我检查了指针的地址，以确保我在内存中找到了正确的位置，但结果已损坏或丢失。

但是，当我注释掉free(buf)时，结果是令人满意的(参见输出2(，尽管内存明显泄漏。

有人能发现我的代码出了什么问题并告诉我吗？我确信我一定忽略了什么？非常感谢。