Index: Lib/tarfile.py
===================================================================
--- Lib/tarfile.py	(revision 84663)
+++ Lib/tarfile.py	(working copy)
@@ -1729,9 +1729,12 @@
             if filemode not in "rw":
                 raise ValueError("mode must be 'r' or 'w'")
 
-            t = cls(name, filemode,
-                    _Stream(name, filemode, comptype, fileobj, bufsize),
-                    **kwargs)
+            stream = _Stream(name, filemode, comptype, fileobj, bufsize)
+            try:
+                t = cls(name, filemode, stream, **kwargs)
+            except:
+                stream.close()
+                raise
             t._extfileobj = False
             return t