gh-112997: Don't log arguments in asyncio unless debugging (#115667)

Nothing else in Python generally logs the contents of variables, so this
can be very unexpected for developers and could leak sensitive
information in to terminals and log files.

1 files changed, 15 insertions, 7 deletions

diff --git a/Lib/asyncio/format_helpers.py b/Lib/asyncio/format_helpers.py
index 27d11fd4fa9..93737b7708a 100644
--- a/Lib/asyncio/format_helpers.py
+++ b/Lib/asyncio/format_helpers.py
@@ -19,19 +19,26 @@ def _get_function_source(func):
     return None
 
 
-def _format_callback_source(func, args):
-    func_repr = _format_callback(func, args, None)
+def _format_callback_source(func, args, *, debug=False):
+    func_repr = _format_callback(func, args, None, debug=debug)
     source = _get_function_source(func)
     if source:
         func_repr += f' at {source[0]}:{source[1]}'
     return func_repr
 
 
-def _format_args_and_kwargs(args, kwargs):
+def _format_args_and_kwargs(args, kwargs, *, debug=False):
     """Format function arguments and keyword arguments.
 
     Special case for a single parameter: ('hello',) is formatted as ('hello').
+
+    Note that this function only returns argument details when
+    debug=True is specified, as arguments may contain sensitive
+    information.
     """
+    if not debug:
+        return '()'
+
     # use reprlib to limit the length of the output
     items = []
     if args:
@@ -41,10 +48,11 @@ def _format_args_and_kwargs(args, kwargs):
     return '({})'.format(', '.join(items))
 
 
-def _format_callback(func, args, kwargs, suffix=''):
+def _format_callback(func, args, kwargs, *, debug=False, suffix=''):
     if isinstance(func, functools.partial):
-        suffix = _format_args_and_kwargs(args, kwargs) + suffix
-        return _format_callback(func.func, func.args, func.keywords, suffix)
+        suffix = _format_args_and_kwargs(args, kwargs, debug=debug) + suffix
+        return _format_callback(func.func, func.args, func.keywords,
+                                debug=debug, suffix=suffix)
 
     if hasattr(func, '__qualname__') and func.__qualname__:
         func_repr = func.__qualname__
@@ -53,7 +61,7 @@ def _format_callback(func, args, kwargs, suffix=''):
     else:
         func_repr = repr(func)
 
-    func_repr += _format_args_and_kwargs(args, kwargs)
+    func_repr += _format_args_and_kwargs(args, kwargs, debug=debug)
     if suffix:
         func_repr += suffix
     return func_repr