#30624 / selectors: use bare except clause in order to not leave the fd in a bad state in case of error (#2082)

Lib/selectors.py

@@ -387,7 +387,7 @@ class _PollLikeSelector(_BaseSelectorImpl):
                 selector_events |= self._EVENT_WRITE
             try:
                 self._selector.modify(key.fd, selector_events)
-            except Exception:
+            except:
                 super().unregister(fileobj)
                 raise
             changed = True
@@ -524,7 +524,7 @@ if hasattr(select, 'kqueue'):
                     kev = select.kevent(key.fd, select.KQ_FILTER_WRITE,
                                         select.KQ_EV_ADD)
                     self._selector.control([kev], 0, 0)
-            except Exception:
+            except:
                 super().unregister(fileobj)
                 raise
             return key

Misc/NEWS

@@ -350,6 +350,10 @@ Extension Modules
 Library
 -------
 
+- bpo-30624: selectors does not take KeyboardInterrupt and SystemExit into
+  account, leaving a fd in a bad state in case of error. Patch by Giampaolo
+  Rodola'.
+
 - bpo-30595: multiprocessing.Queue.get() with a timeout now polls its reader in
   non-blocking mode if it succeeded to aquire the lock but the acquire took
   longer than the timeout.