Move nodes to the end of Linked List function Problem

Question

I'm a student in C programming and I'm just learning the basics for now. I need to write a function that given a linked list in input, put the nodes containing a multiple of 5 and 3 to the end of the list. I'm trying with a sort of recursive approach, but the program crashes. The exercise guidelines say I cannot delete nodes and then recreate them at the end of the list. I must modify pointers.

EDIT: The debugger says it's a segmentation fault problem.

Here there is the image of the debug errors with this list (15 -> 7 -> 2 -> 1 -> 30 -> 25 -> 10) given in input: segfaultdebug

//node is a type I defined for linked list nodes

node *multipleOf3And5ToTail(node *head){

    node *temp2=head;

    if((head->val%3==0)&&(head->val%5==0)&&head!=NULL){

         while(temp2->next!=NULL){
            temp2=temp2->next;
          }

          temp2->next=head;
          head=head->next;
          temp2->next->next=NULL;
          head->next=multipleOf3And5ToTail(head->next);
    }
    else{
         while(((head->val%3!=0)||(head->val%5!=0))&&head!=NULL){
            head=head->next;}
         if((head->val%3==0)&&(head->val%5==0)&&head!=NULL){
            head=multipleOf3And5ToTail(head);
         }
    }
    return head;
}

Answer 1

Thanks guys! I solved my own problem writing a different code.

bool isMultipleOf3And5(int n){
    return n%3==0 && n%5==0;
}

node* getTail(node *head){
    while(head->next != NULL)
        head = head->next;
    return head;
}

node* multipleOf3And5ToTail(node *head){

    node *prev=NULL, *curr=head, *succ=NULL, *tail=NULL, *firstMultipleInTail=NULL;
    
    while(curr != NULL){
        
        while(!isMultipleOf3And5(curr->val) && curr->next != NULL){
            prev = curr;
            curr = curr->next;
            succ = curr->next;
        }
        if(curr == firstMultipleInTail || curr->next == NULL)
            break; // if so, we can stop
        
        if(tail == NULL) {
            // needed to check when we arrive again to it
            firstMultipleInTail = curr;
            tail = getTail(curr);
        }
        
        // put the multiple of 3 and 5 in tail
        tail->next = curr;

        // to adjust pointers:
        // if the multiple was in head, we advance head
        if(prev == NULL) head = head->next;
        // else we link the prev to the succ
        else prev->next = succ;

        // advance curr
        curr = curr->next;
        // set the end of list to NULL
        tail->next->next = NULL;
        // update the tail
        tail = tail->next;
    }

    return head;
}