Bug 960168

Summary: failed incoming SSL connection stays open
Product: Red Hat Enterprise Linux 6 Reporter: Saveliev Peter <peet>
Component: pythonAssignee: Matej Stuchlik <mstuchli>
Status: CLOSED ERRATA QA Contact: Jan Kepler <jkejda>
Severity: medium Docs Contact:
Priority: unspecified    
Version: 6.4CC: bkabrda, fholec, jberan, jkejda, lnovich, michal.skrivanek, mstuchli
Target Milestone: rc   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: python-2.6.6-47.el6 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2013-11-21 09:14:59 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Attachments:
Description Flags
simple SSL server testcase
none
SSL fix backported from 2.7 none

Description Saveliev Peter 2013-05-06 15:31:22 UTC
Description of problem
======================

Having a server with SSLSocket waiting for connections, the incoming connection, failed on automatic do_handshake(), stays open forever — accept() raises the SSLError and does not return client connection socket.

How reproducible
================

146%

Steps to reproduce
==================

server side:

1. create a SOCK_STREAM socket
2. wrap it with wrap_socket()
3. listen()
4. accept()

client side:

1. telnet to this port
2. enter any random text
  

Expected results
================

1. Incoming connection is closed and client disconnected

Actual results
==============

1. On the server side, due to exception, the reference to the incoming connection gets lost.
2. The client stays connected as long as the server operates.

Actually, this issue can lead to unintentional DoS, if a client will try open new connections on a failure — without explicit closing failed ones.

Possible fix
============

Add into do_handshake() something like that:

    try:
        self._sslobj.do_handshake()
    except SSLError as e:
        self._sock.close()
        raise e

Additional info
===============

Python bugzilla issue: http://bugs.python.org/issue17918
Important: only Python2 versions are affected. Python3 works OK.
Possibly related issue: http://bugs.python.org/issue12378 (differs: see the line above)

Comment 1 Saveliev Peter 2013-05-06 15:32:30 UTC
Created attachment 744237 [details]
simple SSL server testcase

Comment 3 Saveliev Peter 2013-05-07 08:37:33 UTC
Upstream issue is fixed and closed. Tested OK.

Merged into cpython 2.7 branch as http://hg.python.org/cpython/rev/85e5a93e534e

Comment 4 Bohuslav "Slavek" Kabrda 2013-05-22 12:20:55 UTC
This fix is easily backportable to RHEL 6 python-2.6.

Comment 5 Matej Stuchlik 2013-06-03 10:49:03 UTC
Created attachment 756235 [details]
SSL fix backported from 2.7

Comment 14 errata-xmlrpc 2013-11-21 09:14:59 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHSA-2013-1582.html