为什么我得到 memory 在无法访问时仍然可以访问

Question

this is the struct of list:

struct link {
    char name[20]; 
    list* next;
};

this is the function that valgrind say that the memory is still reachable.

list* make_new_link(char* name) {
    list* new_link = (list*)malloc(sizeof(list));
    new_link->name = name;
    new_link->next = NULL;

    return new_link;

}

at the end of the code I freed the list like so: NOTE: list* lst is the pointer of the list

void free_list(list* lst) {
    list* temp = NULL;

    while(lst->next != NULL) {
        temp = lst;
        lst = lst->next;
        free(temp);
    }
}

so why I still get an memory problem?

Answer 1

You never clean up the first element because of while(lst->next != NULL) . Fix it like this:

void free_list(list* lst) {
    list* temp = NULL;

    while(lst != NULL) {
        temp = lst;
        lst = lst->next;
        free(temp);
    }
}