C++ 内部realloc()的未定义行为

我正在try 编写一个PE解析器，我的程序包含两个循环，如下所示:

    size_t i = 0;
    while (condition_1) {
        struct _IMAGE_IMPORT_DESCRIPTOR64 *importDescriptorArray = malloc(sizeof(struct _IMAGE_IMPORT_DESCRIPTOR64));

        struct _IMAGE_THUNK_DATA64 *originalFirstThunkArray = malloc(sizeof(struct _IMAGE_THUNK_DATA64));

        size_t originalFirstThunkArrayIndex = 0;

        originalFirstThunkArray[originalFirstThunkArrayIndex].u1.ordinal = some_value; //set to a computed value

        while (condition_2) {
            originalFirstThunkArrayIndex++;

            originalFirstThunkArray = realloc(originalFirstThunkArray, originalFirstThunkArrayIndex * sizeof(struct _IMAGE_THUNK_DATA64));

            originalFirstThunkArrayOffset += sizeof(QWORD); //each element has its address stored as a QWORD, so I have to iterate QWORD-at-a-time.
            originalFirstThunkArray[originalFirstThunkArrayIndex].u1.ordinal = reverse_endianess_u_int64_t(readQWord(file, originalFirstThunkArrayOffset, QWORD_Buffer));
        }

        i++;
        importDescriptorArray = realloc(importDescriptorArray, i * sizeof(struct _IMAGE_IMPORT_DESCRIPTOR64));
    }

我可以执行外部循环n次，它总是会给我正确的输出.然而，inner循环会随机给出正确答案，或者通过malloc: Incorrect checksum for freed object错误消息退出.

我的代码库超出了复制/粘贴的范围，但以下是 struct 的定义:

struct _IMAGE_IMPORT_DESCRIPTOR64 {
    union {
        DWORD Characteristics;
        IMAGE_THUNK_DATA32 OriginalFirstThunk;
    } u;
    DWORD timeDateStamp;
    DWORD forwarderChain;
    DWORD name;
    IMAGE_THUNK_DATA32 FirstThunk;
} IMAGE_IMPORT_DESCRIPTOR64;

typedef struct _IMAGE_THUNK_DATA64 {
    union {
        QWORD forwarderString;
        QWORD function;
        QWORD ordinal;
        QWORD addressOfData;
    } u1;
} IMAGE_THUNK_DATA64;

我已经将导致错误的行缩小到内部循环的realloc()函数，但我不能理解原因-是因为我在重新分配之后立即访问数组(但我更改了索引，以便编辑新分配的空间的数据，而不是其他内容)？

我try 做的是一次分配一个 struct (为了节省内存)，因为除非在满足特定条件之前读取这些 struct ，否则没有其他方法可以知道它们有多少.