让valgrind开心vs避免segfault

我是C语言的新手,尝试学习char数组的动态内存分配,不知道为什么我不能让valgrind在避免segfault的同时也对0个错误感到满意。我的示例基于以下示例:

How to dynamically allocate memory for char** in C

根据该示例,我编写了以下测试代码:

#include <stdlib.h>
#include <stdio.h>

int main (int argc, char* argv[]){
        char **myChar;

        int nEl = 5;
        int nChars = 10;

        myChar = (char**)malloc(sizeof(char*));
        for (int it = 0; it < nEl; it++) {
                myChar[it] = (char*)malloc((nChars) * sizeof(char));
        }

        //for (int it = 0; it < nEl; it++) {
        //        free(myChar[it]);
        //}
        //free(myChar);

        return 0;
}

它按原样编译,运行正常,退出时返回0x0,但valgrind抱怨:

4 errors in context 1 of 1:
Invalid write of size 8
   at 0x400583: main (in /home/username/Documents/personal/tmp/cprog2/test2)
 Address 0x5204048 is 0 bytes after a block of size 8 alloc'd
   at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
   by 0x40054D: main (in /home/username/Documents/personal/tmp/cprog2/test2)

ERROR SUMMARY: 4 errors from 1 contexts (suppressed: 0 from 0)

考虑到valgrind希望malloc'd**myChar和myChar[it]是free(),我取消了注释位,但程序segfaults和valgrind说:

4 errors in context 1 of 2:
Invalid read of size 8
   at 0x4005EF: main (in /home/username/Documents/personal/tmp/cprog2/test2)
 Address 0x5204048 is 0 bytes after a block of size 8 alloc'd
   at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
   by 0x40058D: main (in /home/username/Documents/personal/tmp/cprog2/test2)


4 errors in context 2 of 2:
Invalid write of size 8
   at 0x4005C3: main (in /home/username/Documents/personal/tmp/cprog2/test2)
 Address 0x5204048 is 0 bytes after a block of size 8 alloc'd
   at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
   by 0x40058D: main (in /home/username/Documents/personal/tmp/cprog2/test2)

ERROR SUMMARY: 8 errors from 2 contexts (suppressed: 0 from 0)

为什么我不能让valgrind开心,编译并运行一个工作应用程序?