[3.15] gh-149816: add missing critical section on self in buffered_iternext (GH-15029...

gh-149816: add missing critical section on self in buffered_iternext (GH-150295)
(cherry picked from commit e8545ed3eafbf349b51ea308126a67dc70416a62)

Co-authored-by: Kumar Aditya <kumaraditya@python.org>

diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index 0fdae7b2d210040bb7ab28db6f7c684388291088..5537947f6a51c113e0ba86460834464c282a305d 100644 (file)
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -1509,7 +1509,9 @@ buffered_iternext(PyObject *op)
         tp == state->PyBufferedRandom_Type)
     {
         /* Skip method call overhead for speed */
+        Py_BEGIN_CRITICAL_SECTION(self);
         line = _buffered_readline(self, -1);
+        Py_END_CRITICAL_SECTION();
     }
     else {
         line = PyObject_CallMethodNoArgs((PyObject *)self,