Question

I freed a pointer that I made, but Valgrind still reports that I’ve lost bytes, so I’m not really sure how to approach it.

The code in question Is:

listNode* temp = (listNode*)malloc(sizeof(listNode));
node = list->head;
while (node != NULL)
{
    temp = node->next;
    free(node->entry);
    free(node);
    node = temp;
}
free(temp);

With the valgrind output:

16 bytes in 1 blocks are definitely lost in loss record 13 of 21
==2137==    at 0xB823: malloc (vg_replace_malloc.c:266)
==2137==    by 0x100001B1E: freeList (main.c:110)
==2137==    by 0x100001CB5: main (main.c:157)

Answer 1

You don’t free the memory allocated with malloc in the code given, unless node == NULL. You allocate a block of memory, assign it to temp, then go on in the loop to reassign to temp other addresses, losing the memory that you’ve allocated with malloc.

It doesn’t look like you need the malloc at all: you’re just using temp as a temporary pointer: why do you need to allocate memory for it?