Coverity scan reports this for bufferedio.c :

Error: RESOURCE_LEAK (CWE-772): [#def23]
Python-2.7.15/Modules/_io/bufferedio.c:1353: alloc_fn: Storage is returned from allocation function "PyString_FromStringAndSize".
Python-2.7.15/Objects/stringobject.c:88:5: alloc_fn: Storage is returned from allocation function "PyObject_Malloc".
Python-2.7.15/Objects/obmalloc.c:982:5: alloc_fn: Storage is returned from allocation function "malloc".
Python-2.7.15/Objects/obmalloc.c:982:5: return_alloc_fn: Directly returning storage allocated by "malloc".
Python-2.7.15/Objects/stringobject.c:88:5: var_assign: Assigning: "op" = "PyObject_Malloc(37UL + size)".
Python-2.7.15/Objects/stringobject.c:111:5: return_alloc: Returning allocated memory "op".
Python-2.7.15/Modules/_io/bufferedio.c:1353: var_assign: Assigning: "data" = storage returned from "PyString_FromStringAndSize(self->buffer + self->pos, current_size)".
Python-2.7.15/Modules/_io/bufferedio.c:1366: leaked_storage: Variable "data" going out of scope leaks the storage it points to.
 1364|           if (res == NULL) {
 1365|               Py_DECREF(chunks);
 1366|->             return NULL;
 1367|           }
 1368|           Py_CLEAR(res);