python
diff --git a/‎Lib/test/test_csv.py
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+8-1Lines changed: 8 additions & 1 deletion b/‎Lib/test/test_csv.py
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+8-1Lines changed: 8 additions & 1 deletion
diff --git a/‎Misc/NEWS.d/next/Library/2023-05-07-19-56-45.gh-issue-104265.fVblry.rst
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+4Lines changed: 4 additions & 0 deletions b/‎Misc/NEWS.d/next/Library/2023-05-07-19-56-45.gh-issue-104265.fVblry.rst
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+4Lines changed: 4 additions & 0 deletions
diff --git a/‎Modules/_csv.c
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+2-2Lines changed: 2 additions & 2 deletions b/‎Modules/_csv.c
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+2-2Lines changed: 2 additions & 2 deletions
@@ -10,7 +10,7 @@
 import gc
 import pickle
 from test import support
-from test.support import warnings_helper
+from test.support import warnings_helper, import_helper, check_disallow_instantiation
 from itertools import permutations
 from textwrap import dedent
 from collections import OrderedDict
@@ -1390,5 +1390,12 @@ def test_subclassable(self):
         # issue 44089
         class Foo(csv.Error): ...
 
+    @support.cpython_only
+    def test_disallow_instantiation(self):
+        _csv = import_helper.import_module("_csv")
+        for tp in _csv.Reader, _csv.Writer:
+            with self.subTest(tp=tp):
+                check_disallow_instantiation(self, tp)
+
 if __name__ == '__main__':
     unittest.main()
@@ -0,0 +1,4 @@
+Prevent possible crash by disallowing instantiation of the
+:class:`!_csv.Reader` and :class:`!_csv.Writer` types.
+The regression was introduced in 3.10.0a4 with PR 23224 (:issue:`14935`).
+Patch by Radislav Chugunov.
@@ -1000,7 +1000,7 @@ PyType_Spec Reader_Type_spec = {
     .name = "_csv.reader",
     .basicsize = sizeof(ReaderObj),
     .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC |
-              Py_TPFLAGS_IMMUTABLETYPE),
+              Py_TPFLAGS_IMMUTABLETYPE | Py_TPFLAGS_DISALLOW_INSTANTIATION),
     .slots = Reader_Type_slots
 };
 
@@ -1425,7 +1425,7 @@ PyType_Spec Writer_Type_spec = {
     .name = "_csv.writer",
     .basicsize = sizeof(WriterObj),
     .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC |
-              Py_TPFLAGS_IMMUTABLETYPE),
+              Py_TPFLAGS_IMMUTABLETYPE | Py_TPFLAGS_DISALLOW_INSTANTIATION),
     .slots = Writer_Type_slots,
 };