c - Trying to free an invalid pointer -

i've got a

*** glibc detected *** [...] free(): invalid pointer: 0x0804d0d0 *** 

in function:

ptrgbloque determinar_nodo(const char* path){     // si es el directorio raiz, devuelve 0:     if(!strcmp(path, "/")) return 0;      int fd, i, nodo_anterior, aux;     // super_path usado para obtener la parte superior del path, sin el nombre.     char *super_path = (char*) malloc(strlen(path)), *nombre = (char*) malloc(strlen(path));     char *start = nombre, *start_super_path = super_path; //estos liberaran memoria.     struct grasa_file_t *node, *inicio;     unsigned char *node_name;     strcpy(super_path, path);     strcpy(nombre, path);     // obtiene y acomoda el nombre del archivo.     if (lastchar(path, '/')) {             nombre[strlen(nombre)-1] = '\0';     }     nombre = strrchr(nombre, '/');     nombre[0] = '\0';     nombre = &nombre[1]; // acomoda el nombre, ya que el primer digito siempre es '/'      // acomoda el super_path     if (lastchar(super_path, '/')) {             super_path[strlen(super_path)-1] = '\0';     }     aux = strlen(super_path) - strlen(nombre);     super_path[aux] = '\0';      nodo_anterior = determinar_nodo(super_path);      // abrir conexion y traer directorios, guarda el bloque de inicio para luego liberar memoria     if ((fd = open(disc_path, o_rdonly, 0)) == -1) {             printf("error");             return -enoent;     }     node = (void*) mmap(null, header_size_b + bitmap_size_b + node_table_size_b , prot_read, map_shared, fd, 0);     inicio = node;     node = &(node[gfilebyblock + bitmap_block_size]);      // busca el nodo sobre el cual se encuentre el nombre.     node_name = &(node->fname[0]);     (i = 0; ( (node->parent_dir_block != nodo_anterior) | (strcmp(nombre, (char*) node_name) != 0) | (node->state == 0)) &  (i < gfilebytable) ; i++ ){             node = &(node[1]);             node_name = &(node->fname[0]);     }      // cierra conexiones y libera memoria.     free(start);     free(start_super_path);     if (munmap(inicio, header_size_b + bitmap_size_b + node_table_size_b) == -1) printf("error");     close(fd);     if (i >= gfilebytable) return -1;     return (i+1); } 

the problem happens when call function with:

determinar_nodo("/otra carpetita/inside otra/inside otra otra :d/"); 

there many redundant steps in code because of debbuging, try step them over.

which matters me memory problem. notice @ beggining of declarations create start , start_super_path pointers not loose address free @ end of function. in addition, seems function breaks @ second call if it. means first "free" working properly, correspond call of determinar_nodo("/otra carpetita/"), breaks @ free of call determinar_nodo("/otra carpetita/inside otra/").

debbuging on memory browser, notice adresses function trying free indeed correct, don't know going on. anyway, if free of those, got mentioned error.

thanks in advance help, , please forgive poor english.

you must have (char*) malloc(strlen(path)+1) (+1 \0 terminating character).

otherwise, you'll have buffer overflow can corrupt heap.
related link: how malloc() , free() work?