[3.11] gh-108342: Break ref cycle in SSLSocket._create() exc (GH-108344) (#108349)

miss-islington · vstinner · web-flow · commit 93714b7db795 · 2023-08-23T12:10:04.000+02:00
Explicitly break a reference cycle when SSLSocket._create() raises an exception. Clear the variable storing the exception, since the exception traceback contains the variables and so creates a reference cycle. This test leak was introduced by the test added for the fix of GH-108310. (cherry picked from commit 64f9935) Co-authored-by: Victor Stinner <vstinner@python.org>
diff --git a/Lib/ssl.py b/Lib/ssl.py
@@ -1083,7 +1083,11 @@ def _create(cls, sock, server_side=False, do_handshake_on_connect=True,
                     self.close()
                 except OSError:
                     pass
-                raise notconn_pre_handshake_data_error
+                try:
+                    raise notconn_pre_handshake_data_error
+                finally:
+                    # Explicitly break the reference cycle.
+                    notconn_pre_handshake_data_error = None
         else:
             connected = True
 
