Bug 1579432

Summary: OSError 17 due to _multiprocessing/semaphore.c assuming a one-to-one Pid -> process mapping.
Product: Red Hat Enterprise Linux 7 Reporter: Bill Nottingham <notting>
Component: pythonAssignee: Python Maintainers <python-maint>
Status: CLOSED ERRATA QA Contact: Jan Kepler <jkejda>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 7.5CC: cstratak, jkejda, pviktori
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
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Fixed In Version: python-2.7.5-74.el7 Doc Type: If docs needed, set a value
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Clone Of: Environment:
Last Closed: 2018-10-30 07:55:14 UTC Type: Bug
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description Bill Nottingham 2018-05-17 15:52:44 UTC 
Description of problem:

Python < 2.7.12 has a bug in its semaphore code that leads to errors when used with pid namespaces.

See: https://bugs.python.org/issue24303

This was fixed in 2.7.12 and 3.x, but RHEL 7 python still has this bug.


Version-Release number of selected component (if applicable):

2.7.5-68.el7.x86_64

How reproducible: 100%

Steps to Reproduce:
1. Run the following script

...
#!/bin/sh

for i in `seq 1 50`; do
  bwrap --unshare-uts --unshare-ipc --unshare-pid --proc /proc --dev-bind / / python -c "for i in range(500): import multiprocessing; print multiprocessing.Queue()" &
done | grep --line-buffered OSError
...

Actual results:

a smattering of:

```
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib64/python2.7/multiprocessing/__init__.py", line 218, in Queue
    return Queue(maxsize)
  File "/usr/lib64/python2.7/multiprocessing/queues.py", line 68, in __init__
    self._wlock = Lock()
  File "/usr/lib64/python2.7/multiprocessing/synchronize.py", line 147, in __init__
    SemLock.__init__(self, SEMAPHORE, 1, 1)
  File "/usr/lib64/python2.7/multiprocessing/synchronize.py", line 75, in __init__
    sl = self._semlock = _multiprocessing.SemLock(kind, value, maxvalue)
OSError: [Errno 17] File exists
```

Expected results:

no errors

Additional info:

This is breaking Ansible Tower with a number of RHEL customers.
Comment 7 errata-xmlrpc 2018-10-30 07:55:14 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.

https://access.redhat.com/errata/RHSA-2018:3041