Abort trap 6: Freeing unallocated pointer

Here is code to destroy a circularly linked list. When it runs, it produces an abort trap 6: pointer being freed was not allocated

NODE *roamer = list->head;
        do{
            NODE *oldRoamer = roamer;
            roamer = roamer->next;
            printf("freeing prev");
            free(oldRoamer);
            printf("prev freed");
        }while (roamer != NULL);

The program prints both printf statements a bunch of times, but then gives the error just after printing "freeing prev".