Stuck debugging a problem that I think is related to malloc - c

Question

i'm currently writing a program that makes a sorted linked list in C. I'm new to C and am running into errors that I think are based around malloc. I would love if someone can give me some insight on my problems and how to fix them.
These are some of the errors I'm encountering:
==50002==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x563f6970912c bp 0x7ffe5d2b03f0 sp 0x7ffe5d2b03d0 T0)
==50002==The signal is caused by a WRITE memory access.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct node {
int data;
struct node* next;
};
void insert(struct node** n_ref, struct node* newNode) {
struct node* curr;
if (*n_ref == NULL || (*n_ref)->data >= newNode->data) {
newNode->next = *n_ref;
*n_ref = newNode;
} else {
curr = *n_ref;
while (curr->next != NULL && curr->next->data < newNode->data) {
curr = curr->next;
}
newNode->next = curr->next;
curr->next = newNode;
}
}
struct node* makeNode(int num){
struct node* newNode = NULL;
newNode->data = num;
newNode->next = NULL;
return newNode;
}
void delete(struct node** n, int num) {
struct node* temp = *n, *prev;
if (temp != NULL && temp->data == num) {
*n = temp->next;
free(temp);
return;
}
while (temp != NULL && temp->data != num) {
prev = temp;
temp = temp->next;
}
if (temp == NULL) {
return;
}
prev->next = temp->next;
free(temp);
}
void print(struct node* n) {
while (n != NULL) {
printf("%d ", n->data);
n = n->next;
}
}
int duplicate(struct node* n, int num) {
while (n != NULL) {
if (n->data == num) {
return 1;
}
n = n->next;
}
return 0;
}
int main(int argc, char* argv[argc + 1]) {
if (argc < 2) {
return EXIT_SUCCESS;
}
struct node* head = NULL;
FILE *file = fopen(argv[1], "r");
int x;
char str[10];
while (fscanf(file, "%s %d\n", str, &x) != EOF) {
if (strcmp(str, "INSERT")) {
if (duplicate(head, x) == 0) {
struct node* newNode;
newNode = (struct node*)malloc(sizeof(struct node));
newNode = makeNode(x);
insert(&head, newNode);
}
} else if (strcmp(str, "DELETE")) {
delete(&head, x);
}
print(head);
}
fclose(file);
return EXIT_SUCCESS;
}
Sorry for it being so messy. This is my first post here.

Answer 1

The original posted makeNode() assigns a local pointer to NULL and dereferences that 2x. Suggest allocating space and check the result, eg:
struct node* makeNode(int num) {
struct node* newNode;
newNode = malloc(sizeof(*newNode));
if (newNode) {
newNode->data = num;
newNode->next = NULL;
}
return newNode;
}