在对链表进行排序时出现分段错误

Question

everytime I run this loop , I get a segmentation fault in the second iteration of the loop .

node *new,*new1;

new=(node*) malloc(sizeof(node));
new1=(node*) malloc(sizeof(node));
new = start->next;

for(;new->next != NULL;new = new->next)
{
    for(new1=new->next;new1 != NULL;new1=new1->next)
    {   //printf("LOOP\n");
        if(new->data > new1->data)   
        {
            printf("\n Swapping - new:%d and  new1:%d\n",new->data,new1->data); 
            temp = (node*) malloc(sizeof(node));
            temp1 = (node*) malloc(sizeof(node));
            temp1 = new->next;
            temp = new1->next;
            new->next = temp;
            printf("Temp var : %d\n",temp->data);
            printf("Temp1 var : %d\n",temp1->data);
            new1->next = new;

            new1 = new;
            new = temp1;
            printf("After swapping , new:%d and new1 : %d\n",new->data,new1->data);
            //        free(temp);
            //       free(temp1);
        }
    }
} 

Whenever I give a list to it - eg. 4,1,9,6 it only swaps 4 and 1 , when it is the iteration to swap 9 and 6 , it shows and segmentation fault .

Answer 1

After executing temp = new1->next; , temp could be NULL if new1 was the last node of the list. While temp is NULL , it would raise a segment error when you visit it's field in this line printf("Temp var : %d\\n",temp->data);