bpo-38858: Fix ref leak in pycore_interp_init() (GH-17512)

vstinner · web-flow · commit 080ee5a88406 · 2019-12-08T21:55:58.000+01:00
bpo-38858, bpo-38997: _PySys_Create() returns a strong reference to the sys module: Py_DECREF() is needed when we are done with the module.
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
@@ -705,24 +705,29 @@ static PyStatus
 pycore_interp_init(PyThreadState *tstate)
 {
     PyStatus status;
+    PyObject *sysmod = NULL;
 
     status = pycore_init_types(tstate);
     if (_PyStatus_EXCEPTION(status)) {
-        return status;
+        goto done;
     }
 
-    PyObject *sysmod;
     status = _PySys_Create(tstate, &sysmod);
     if (_PyStatus_EXCEPTION(status)) {
-        return status;
+        goto done;
     }
 
     status = pycore_init_builtins(tstate);
     if (_PyStatus_EXCEPTION(status)) {
-        return status;
+        goto done;
     }
 
-    return pycore_init_import_warnings(tstate, sysmod);
+    status = pycore_init_import_warnings(tstate, sysmod);
+
+done:
+    /* sys.modules['sys'] contains a strong reference to the module */
+    Py_XDECREF(sysmod);
+    return status;
 }
 
 

Original file line number	Diff line number	Diff line change
`@@ -705,24 +705,29 @@ static PyStatus`
`705`	`705`	`pycore_interp_init(PyThreadState *tstate)`
`706`	`706`	`{`
`707`	`707`	`PyStatus status;`
	`708`	`+ PyObject *sysmod = NULL;`
`708`	`709`
`709`	`710`	`status = pycore_init_types(tstate);`
`710`	`711`	`if (_PyStatus_EXCEPTION(status)) {`
`711`		`- return status;`
	`712`	`+ goto done;`
`712`	`713`	`}`
`713`	`714`
`714`		`- PyObject *sysmod;`
`715`	`715`	`status = _PySys_Create(tstate, &sysmod);`
`716`	`716`	`if (_PyStatus_EXCEPTION(status)) {`
`717`		`- return status;`
	`717`	`+ goto done;`
`718`	`718`	`}`
`719`	`719`
`720`	`720`	`status = pycore_init_builtins(tstate);`
`721`	`721`	`if (_PyStatus_EXCEPTION(status)) {`
`722`		`- return status;`
	`722`	`+ goto done;`
`723`	`723`	`}`
`724`	`724`
`725`		`- return pycore_init_import_warnings(tstate, sysmod);`
	`725`	`+ status = pycore_init_import_warnings(tstate, sysmod);`
	`726`	`+`
	`727`	`+done:`
	`728`	`+ /* sys.modules['sys'] contains a strong reference to the module */`
	`729`	`+ Py_XDECREF(sysmod);`
	`730`	`+ return status;`
`726`	`731`	`}`
`727`	`732`
`728`	`733`