From: "akr (Akira Tanaka)" <akr@...>
Date: 2013-08-25T00:23:09+09:00
Subject: [ruby-core:56797] [ruby-trunk - Bug #8816][Third Party's Issue]	Tempfile.new may return the same name for parallel calls


Issue #8816 has been updated by akr (Akira Tanaka).

Status changed from Open to Third Party's Issue

Tempfile.new creates a normal file, not unix socket.
So, your report is questionable.

Note that Tempfile uses O_EXCL to exclusive file creation.
If it doesn't work, it is a problem of kernel.

I checked kgio.
It seems the temporary file created by Tempfile.new is removed and
unix socket is created the name.

http://bogomips.org/kgio.git/tree/test/test_unix_connect.rb :

  class TestKgioUnixConnect < Test::Unit::TestCase

    def setup
      tmp = Tempfile.new('kgio_unix')
      @path = tmp.path
      File.unlink(@path)
      tmp.close rescue nil
      @srv = Kgio::UNIXServer.new(@path)
      @addr = Socket.pack_sockaddr_un(@path)
    end

The race condition should be solved by application.
Because another process may creates the file between unlink and unix socket creation.
Tempfile cannot do anything between them because Tempfile methods are not running at that time.

----------------------------------------
Bug #8816: Tempfile.new may return the same name for parallel calls
https://bugs.ruby-lang.org/issues/8816#change-41338

Author: 375gnu (Hleb  Valoshka)
Status: Third Party's Issue
Priority: Normal
Assignee: 
Category: 
Target version: 
ruby -v: ruby 1.9.3p194 (2012-04-20 revision 35410) [x86_64-linux]
Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN


Two simultaneous call to Tempfile.new may return the same name. This may lead
to race conditions.

There some examples of such races (unix socket can't be unlinked because it was
unlinked by another test case):

https://buildd.debian.org/status/fetch.php?pkg=ruby-kgio&arch=ia64&ver=2.8.0-1&stamp=1376819434
https://buildd.debian.org/status/fetch.php?pkg=ruby-kgio&arch=kfreebsd-i386&ver=2.8.0-1&stamp=1376820662



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