c - Valgrind newbie, can't seem to make it happy -

i'm working through cs50 course online, , task @ hand load dictionary memory (i'm using chained hash table data structure), , check contents of text file against words in dictionary. wrote load() function loads dictionary file , stores every word memory. function returns true when words loaded. valgrind shows no memory leaks. problem have ridiculous amount of read/write errors. helped me pinpoint seem coming , i've been scouring interwebs can't seem make heads or tails of it.

here's relevant code:

#include <stdbool.h> #include <stdio.h> #include <stdlib.h> #include <string.h>  #define hash_size 10 #define length 45  typedef struct node {     char* word;     struct node* next; } node;  // globals node* hashtable[hash_size]; unsigned int dictionary_size = 0;  /**  * loads dictionary memory.  returns true if successful else false.  **/ bool load(const char* dictionary) {     // initialize variables     char currentword[length + 1];     int tableindex;      // open dictionary     file* dict = fopen(dictionary, "r");     if (dict == null)         return false;      while(fscanf(dict, "%s", currentword) == 1)     {         // hash value of word         tableindex = hash(currentword);          // initialize new node         node* newnode = malloc(sizeof(node));         newnode->word = malloc((strlen(currentword) + 1) * sizeof(char));         if (newnode == null || newnode->word == null)         {             printf("error: out of memory\n");             return false;         }          // copy word new node         strcpy(newnode->word, currentword);         newnode->next = null;          // if no collision, hash word head of list         if (hashtable[tableindex] == null)             hashtable[tableindex] = newnode;          // create pointer , move down list         else         {             node* ptrnode = hashtable[tableindex];              while (ptrnode->next != null)                 ptrnode = ptrnode->next;              // append node end of linked list             ptrnode->next = newnode;         }          // increase dictionary size         dictionary_size++;          // free word member before actual node         free(newnode->word);         free(newnode);     }      // close dictionary , return true     fclose(dict);     return true; } 

and valgrind:

==32487== invalid read of size 4 ==32487==    @ 0x8048989: load (my_new_test.c:120) ==32487==    0x804873d: main (my_new_test.c:53) ==32487==  address 0x423b30c 4 bytes inside block of size 8 free'd ==32487==    @ 0x402b3d8: free (in /usr/lib/valgrind/vgpreload_memcheck-x86-   linux.so) ==32487==    0x80489d3: load (my_new_test.c:132) ==32487==    0x804873d: main (my_new_test.c:53) ==32487==  ==32487== invalid write of size 4 ==32487==    @ 0x80489aa: load (my_new_test.c:124) ==32487==    0x804873d: main (my_new_test.c:53) ==32487==  address 0x423b30c 4 bytes inside block of size 8 free'd ==32487==    @ 0x402b3d8: free (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so) ==32487==    0x80489d3: load (my_new_test.c:132) ==32487==    0x804873d: main (my_new_test.c:53) ==32487==  ==32487== invalid read of size 4 ==32487==    @ 0x8048999: load (my_new_test.c:121) ==32487==    0x804873d: main (my_new_test.c:53) ==32487==  address 0x423bb24 4 bytes inside block of size 8 free'd ==32487==    @ 0x402b3d8: free (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so) ==32487==    0x80489d3: load (my_new_test.c:132) ==32487==    0x804873d: main (my_new_test.c:53)  ==32487== heap summary: ==32487==     in use @ exit: 0 bytes in 0 blocks ==32487==   total heap usage: 286,183 allocs, 286,183 frees, 2,584,308 bytes        allocated ==32487==  ==32487== heap blocks freed -- no leaks possible ==32487==  ==32487== counts of detected , suppressed errors, rerun with: -v ==32487== error summary: 10000000 errors 3 contexts (suppressed: 0  0) 

i'm still raw valgrind gather issue seems inside else statement, pointer created (node* ptrnode). can see i'm not seeing? appreciated!

the problem these 2 lines:

free(newnode->word); free(newnode); 

you added node hash-table, free it, making pointers in hash-table invalid point free'd data.