New submission from Erik Aronesty <[email protected]>:
Depending on the user's permissions, this code can hang, instead of raising an
exception:
from tempfile import NamedTemporaryFile
NamedTemporaryFile(dir="/")
The problamatic code is in tempfile.py:
When encountering a "[Errno 13] Permission denied: '/tmpmcupmo_g'", the current
code uses _os.access(dir, _os.W_OK) in two places to check if access is allowed
to write to the directory.
On windows, _os.access does not check if the user has permission to write to
the folder, it only checks if the folder is read-only (and it doesn't even do a
good job at that).
So the temp file creator loops for a rather long time, and consumes a massive
amount of system resources, because os.TMP_MAX on modern windows versions is
2147483647.
This article explains how to check if a directory can-write without trying to
write to it:
http://blog.aaronballman.com/2011/08/how-to-check-access-rights/
Alternatively, a more careful check of the winerror return value from the open
call *might* be sufficient.
----------
messages: 347073
nosy: earonesty
priority: normal
severity: normal
status: open
title: NamedTemporaryFile can hang on windows
versions: Python 3.6, Python 3.7
_______________________________________
Python tracker <[email protected]>
<https://bugs.python.org/issue37477>
_______________________________________
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
