C linked list searchNode / freeList methods (seg fault) - c

Question

I've been making the transition from Java to learning C for a class. A current exercise is to implement removeAtFront(), searchNode(), and freeList() methods for a LinkedList. I understand theoretically how this works - I'd have it done quickly in Java, I've just tried for hours and don't understand why the below code doesn't work.
The remove method appears to work, producing the correct modified list, until the search method is called AFTER removing a node. Then a seg fault 11 is always produced. The free method also always produces a seg fault.
I'm not asking for people to do my homework, but if I could be pointed in the right direction that'd be much appreciated!
The given Node* struct is:
typedef struct Node
{
char *word;
struct Node *next;
} Node;
The methods outside of main() read like this:
void insertAtFront( Node **head, char * key )
{
Node *new = malloc( sizeof(Node) );
if (!new) fatal("Malloc of new Node failed");
new->word = key;
new->next = *head;
*head = new;
}
void insertAtTail( Node **head, char * word )
{
if (!(*head)) insertAtFront(head, word);
else insertAtTail(&(*head)->next, word);
}
void removeAtFront( Node ** head )
{
Node *tmp = *head;
if (!tmp) return;
*head = tmp->next;
free(tmp->word);
free (tmp);
}
void removeNode( Node ** head, char * key )
{
Node *tmp = searchNode(*head, key);
if (tmp) removeAtFront (&tmp);
}
Node * searchNode ( Node * head, char * key )
{
if (!head || (strcmp(head->word, key) == 0)) return head;
return searchNode(head->next, key);
}
void freeList( Node ** head )
{
if (!head) return;
if (&(*head)->next) freeList (&(*head)->next);
removeAtFront(head);
}
EDIT: One of the comments fixed my problem with the freeList() method, but others asked for more code. The problem with this assignment is that I am only allowed to modify the insertAtTail(), removeAtFront(), remove(), search(), and freeList() methods. I'll post the main method below though. I think the word values are allocated correctly within that though.
Node *searchNode( Node * head, char * key );
void insertAtFront( Node **head, char * key ); // ALREADY WRITTEN FOR YOU
void insertAtTail( Node **head, char * key );
void removeAtFront( Node ** head );
void removeNode( Node **head, char * key );
void freeList( Node **head );
void printList( Node * head ); // ALREADY WRITTEN FOR YOU
void fatal( char * msg ); // ALREADY WRITTEN FOR YOU
#define BUFFER_CAP 20
int main()
{
Node *head = NULL;
while (1)
{
char option;
printf("\nChoose 'H'ead Insert, 'T'ail insert, 'R'emove, 'S'earch, F'ree, 'Q'uit " );
fflush( stdout );
int result = scanf(" %c%*[^\n]", &option); getchar(); // MAGIC BULLET TO CORRECTLY READ A SINGLE CHAR FROM STDIN
if (result <1) fatal("failure reading from stdin\n");
if (option == 'H' )
{
char * word=malloc(BUFFER_CAP); // DONT ENTER ANY LONG WORDS!
printf("Enter a word to insertAtFront: " );
fflush( stdout );
char * result = fgets( word, BUFFER_CAP, stdin );
if (result==NULL) fatal("failure reading from stdin\n");
strtok(word,"\n"); // overwrites '\n' with '\0'
insertAtFront( &head, word ); /* shallow copy string into list */
printList( head );
}
if (option == 'T' )
{
char * word=malloc(BUFFER_CAP); // DONT ENTER ANY LONG WORDS!
printf("Enter a word to insertAtTail: " );
fflush( stdout );
char * result = fgets( word, BUFFER_CAP, stdin );
if (result==NULL) fatal("failure reading from stdin\n");
strtok(word,"\n"); // overwrites '\n' with '\0'
insertAtTail( &head, word ); /* shallow copy string into list */
printList( head );
}
if (option == 'R' )
{
char * word=malloc(BUFFER_CAP); // DONT ENTER ANY LONG WORDS!
printf("Enter a word to remove: " );
fflush( stdout );
char * result = fgets( word, BUFFER_CAP, stdin );
if (result==NULL) fatal("failure reading from stdin\n");
strtok(word,"\n"); // overwrites '\n' with '\0'
removeNode( &head, word );
printList( head );
free( word ); // we were just using it for matching
}
if (option == 'S' )
{
char * word=malloc(BUFFER_CAP); // DONT ENTER ANY LONG WORDS!
printf("Enter a word to find: " );
fflush( stdout );
char * result = fgets( word, BUFFER_CAP, stdin );
if (result==NULL) fatal("failure reading from stdin\n");
strtok(word,"\n"); // overwrites '\n' with '\0'
if (searchNode( head, word ))
fprintf(stderr, "%s FOUND\n",word );
else
fprintf(stderr, "%s NOT FOUND\n",word );
printList( head );
free( word ); // we were just using it for matching
}
if (option == 'F' ) // free the entire list (remember to set head to NULL)
{
freeList( &head );
printList( head );
}
else if (option == 'Q' )
exit( 0 );
} // END WHILE
return 0;
}

Answer 1

when you are allocating memory for node using Node *new = malloc( sizeof(Node) ); , you are allocating memory for pointer but not for data. your are do allocate memory for char also like: (its just an idea)
new->word= malloc(sizeof(char)*(strlen(key) + 1));
strcpy(new->word, key)
Other wise you have to be use that you allocate memory for key dynamically. (because you do free(tmp->word);)
I think you should put some more code. How do you pass key?

Answer 2

Yeah as indicated in earlier answer, you are not allocating memory for word in each node though you have allocated the memory for the node. Sometimes it might work, without causing segfault, at that time you are using "somebody's" memory, that you haven't claimed, causing to corrupt that memory locations.