Don't crash in eval()/exec() on hydrated code with free vars

gvanrossum · gvanrossum · commit 91a7a5e8537a · 2021-07-23T15:56:40.000-07:00
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
@@ -4,6 +4,7 @@
 #include <ctype.h>
 #include "pycore_ast.h"           // _PyAST_Validate()
 #include "pycore_compile.h"       // _PyAST_Compile()
+#include "pycore_code.h"          // Hydration
 #include "pycore_object.h"        // _Py_AddToAllObjects()
 #include "pycore_pyerrors.h"      // _PyErr_NoMemory()
 #include "pycore_pystate.h"       // _PyThreadState_GET()
@@ -967,8 +968,13 @@ builtin_eval_impl(PyObject *module, PyObject *source, PyObject *globals,
         if (PySys_Audit("exec", "O", source) < 0) {
             return NULL;
         }
-
-        if (PyCode_GetNumFree((PyCodeObject *)source) > 0) {
+        PyCodeObject *code = (PyCodeObject *)source;
+        if (!_PyCode_IsHydrated(code)) {
+            if (!_PyCode_Hydrate(code)) {
+                return NULL;
+            }
+        }
+        if (PyCode_GetNumFree(code) > 0) {
             PyErr_SetString(PyExc_TypeError,
                 "code object passed to eval() may not contain free variables");
             return NULL;
@@ -1055,8 +1061,13 @@ builtin_exec_impl(PyObject *module, PyObject *source, PyObject *globals,
         if (PySys_Audit("exec", "O", source) < 0) {
             return NULL;
         }
-
-        if (PyCode_GetNumFree((PyCodeObject *)source) > 0) {
+        PyCodeObject *code = (PyCodeObject *)source;
+        if (!_PyCode_IsHydrated(code)) {
+            if (!_PyCode_Hydrate(code)) {
+                return NULL;
+            }
+        }
+        if (PyCode_GetNumFree(code) > 0) {
             PyErr_SetString(PyExc_TypeError,
                 "code object passed to exec() may not "
                 "contain free variables");
