I get a segmentation fault when implementing a append function for a linked list

I am defining head as a global variable. The user enters integers which should be appended to a singly linked list. I implemented the append function, but it gives me a segmentation fault.

void Append(int x)
{
    struct Node *temp, *current;
    temp = (struct Node*)malloc(sizeof(struct Node));
    temp -> data = x;


    temp -> next = NULL;

    if(head->next ==NULL)
    {
            head = temp;

    }
    else{

            //current = (struct Node*)malloc(sizeof(struct Node));
            current = head;
            while(1)//current != NULL)
            {
                    if(current->next ==NULL)
                    {
                            current =current -> next;
                            printf("added to the end\n");
                            break;
                    }

                    current = current -> next;
            }
    }
}

The main function is given below:

int main()
{
    //create empty List
    head =NULL;

    printf("How many numbers?\n");
    int n,i,x;
    scanf("%d",&n);
    for(i =0; i<n; i++)
    {

            printf("Enter the number\n");
            scanf("%d",&x);
            //Insert(x);
            Append(x);
            Print();
    }
    return 0;
}