C: Correctly using malloc for linked list

Question

I am a beginner to C and have a question about the proper use of malloc/free for pointers, particularly in linked lists. I have implemented a method to add a new node to my linked list. The node "head" is a global variable. After creating a new node, I insert it at the front of my list and reassign head to point to it. Here is the code:

int add_entry(char* first_name, char* last_name, char* address, char* telephone)
{
    struct node* new_node = (struct node*) malloc(sizeof(struct node));
    strcpy(new_node->m_first_name, first_name);
    strcpy(new_node->m_last_name, last_name);
    strcpy(new_node->m_address, address);
    strcpy(new_node->m_telephone, telephone);

    if (num_nodes == 0)
        head = new_node;
    else {
        new_node->m_next = head;
        head = new_node;
    }
    num_nodes++;
    return 1;
}

We were told in class that anytime we use malloc, we should also use free. However, in this case use of free for new_node at the end of the program leads to a segmentation fault. What is the proper way to free memory in this case? Thanks!

Solution 1

void free_list(struct node *head)
{
   struct node *temp;

   while (head) {
       free(head->m_first_name);
       free(head->m_last_name);
       free(head->m_address);
       free(head->m_telephone);
       temp = head;
       head = head->m_next;
       free(temp);
    }
}

Solution 2

way to free your list:

void freeList(struct node* head)
{
   struct node* tmp;

   while (head != NULL)
    {
       tmp = head;
       head = head->next;
       free(tmp);
    }

}