bpo-31787: Prevent refleaks when calling __init__() more than once (GH-3995)

4 files changed, 23 insertions, 13 deletions

diff --git a/Modules/_asynciomodule.c b/Modules/_asynciomodule.c
index e82425b..d66cc4c 100644
--- a/Modules/_asynciomodule.c
+++ b/Modules/_asynciomodule.c
@@ -458,6 +458,7 @@ future_schedule_callbacks(FutureObj *fut)
     return 0;
 }
 
+
 static int
 future_init(FutureObj *fut, PyObject *loop)
 {
@@ -465,6 +466,19 @@ future_init(FutureObj *fut, PyObject *loop)
     int is_true;
     _Py_IDENTIFIER(get_debug);
 
+    // Same to FutureObj_clear() but not clearing fut->dict
+    Py_CLEAR(fut->fut_loop);
+    Py_CLEAR(fut->fut_callback0);
+    Py_CLEAR(fut->fut_context0);
+    Py_CLEAR(fut->fut_callbacks);
+    Py_CLEAR(fut->fut_result);
+    Py_CLEAR(fut->fut_exception);
+    Py_CLEAR(fut->fut_source_tb);
+
+    fut->fut_state = STATE_PENDING;
+    fut->fut_log_tb = 0;
+    fut->fut_blocking = 0;
+
     if (loop == Py_None) {
         loop = get_event_loop();
         if (loop == NULL) {
@@ -474,7 +488,7 @@ future_init(FutureObj *fut, PyObject *loop)
     else {
         Py_INCREF(loop);
     }
-    Py_XSETREF(fut->fut_loop, loop);
+    fut->fut_loop = loop;
 
     res = _PyObject_CallMethodId(fut->fut_loop, &PyId_get_debug, NULL);
     if (res == NULL) {
@@ -486,16 +500,12 @@ future_init(FutureObj *fut, PyObject *loop)
         return -1;
     }
     if (is_true) {
-        Py_XSETREF(fut->fut_source_tb, _PyObject_CallNoArg(traceback_extract_stack));
+        fut->fut_source_tb = _PyObject_CallNoArg(traceback_extract_stack);
         if (fut->fut_source_tb == NULL) {
             return -1;
         }
     }
 
-    fut->fut_callback0 = NULL;
-    fut->fut_context0 = NULL;
-    fut->fut_callbacks = NULL;
-
     return 0;
 }
 
@@ -1938,16 +1948,16 @@ _asyncio_Task___init___impl(TaskObj *self, PyObject *coro, PyObject *loop)
         return -1;
     }
 
-    self->task_context = PyContext_CopyCurrent();
+    Py_XSETREF(self->task_context, PyContext_CopyCurrent());
     if (self->task_context == NULL) {
         return -1;
     }
 
-    self->task_fut_waiter = NULL;
+    Py_CLEAR(self->task_fut_waiter);
     self->task_must_cancel = 0;
     self->task_log_destroy_pending = 1;
     Py_INCREF(coro);
-    self->task_coro = coro;
+    Py_XSETREF(self->task_coro, coro);
 
     if (task_call_step_soon(self, NULL)) {
         return -1;
diff --git a/Modules/_bz2module.c b/Modules/_bz2module.c
index dba0e19..0789b61 100644
--- a/Modules/_bz2module.c
+++ b/Modules/_bz2module.c
@@ -644,7 +644,7 @@ _bz2_BZ2Decompressor___init___impl(BZ2Decompressor *self)
     self->bzs_avail_in_real = 0;
     self->input_buffer = NULL;
     self->input_buffer_size = 0;
-    self->unused_data = PyBytes_FromStringAndSize(NULL, 0);
+    Py_XSETREF(self->unused_data, PyBytes_FromStringAndSize(NULL, 0));
     if (self->unused_data == NULL)
         goto error;
 
diff --git a/Modules/_hashopenssl.c b/Modules/_hashopenssl.c
index 44d3f63..b6dcc06 100644
--- a/Modules/_hashopenssl.c
+++ b/Modules/_hashopenssl.c
@@ -369,8 +369,8 @@ EVP_tp_init(EVPobject *self, PyObject *args, PyObject *kwds)
         return -1;
     }
 
-    self->name = name_obj;
-    Py_INCREF(self->name);
+    Py_INCREF(name_obj);
+    Py_XSETREF(self->name, name_obj);
 
     if (data_obj) {
         if (view.len >= HASHLIB_GIL_MINSIZE) {
diff --git a/Modules/_lzmamodule.c b/Modules/_lzmamodule.c
index fd3bbb8..5bcd088 100644
--- a/Modules/_lzmamodule.c
+++ b/Modules/_lzmamodule.c
@@ -1173,7 +1173,7 @@ _lzma_LZMADecompressor___init___impl(Decompressor *self, int format,
     self->needs_input = 1;
     self->input_buffer = NULL;
     self->input_buffer_size = 0;
-    self->unused_data = PyBytes_FromStringAndSize(NULL, 0);
+    Py_XSETREF(self->unused_data, PyBytes_FromStringAndSize(NULL, 0));
     if (self->unused_data == NULL)
         goto error;