test_ssl memory leak

[mdickinson]

BPO	9497
Nosy	@mdickinson
Files	test_ssl_leak_report.txt

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = 'https://github.com/mdickinson'
closed_at = <Date 2010-08-03.18:55:33.803>
created_at = <Date 2010-08-03.17:50:11.153>
labels = ['extension-modules', 'performance']
title = 'test_ssl memory leak'
updated_at = <Date 2010-08-03.18:55:33.800>
user = 'https://github.com/mdickinson'

bugs.python.org fields:

activity = <Date 2010-08-03.18:55:33.800>
actor = 'mark.dickinson'
assignee = 'mark.dickinson'
closed = True
closed_date = <Date 2010-08-03.18:55:33.803>
closer = 'mark.dickinson'
components = ['Extension Modules']
creation = <Date 2010-08-03.17:50:11.153>
creator = 'mark.dickinson'
dependencies = []
files = ['18348']
hgrepos = []
issue_num = 9497
keywords = []
message_count = 3.0
messages = ['112637', '112645', '112651']
nosy_count = 2.0
nosy_names = ['mark.dickinson', 'janssen']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'resource usage'
url = 'https://bugs.python.org/issue9497'
versions = ['Python 2.6', 'Python 3.1', 'Python 2.7', 'Python 3.2']

[mdickinson]

On OS X 10.6, with a 64-bit build of Python, regrtest -L is showing leaks from test_ssl. Here are the first few lines of the output; I've also attached the full output.

newton:py3k dickinsm$ ./python.exe -m test.regrtest -L test_ssl
[1/1] test_ssl
1 test OK.
leaks Report Version: 2.0
Process: python.exe [36421]
Path: /Users/dickinsm/python/svn/py3k/python.exe
Load Address: 0x100000000
Identifier: python.exe
Version: ??? (???)
Code Type: X86-64 (Native)
Parent Process: bash [80529]

Date/Time: 2010-08-03 18:48:10.072 +0100
OS Version: Mac OS X 10.6.4 (10F569)
Report Version: 6

Process 36421: 8194 nodes malloced for 15049 KB
Process 36421: 106 leaks for 4080 total leaked bytes.
Leak: 0x10173df50 size=272 zone: DefaultMallocZone_0x1002f7000 string '/C=US/ST=Delaware/L=Wilmington/O=Python Software Foundation/OU=SSL/CN=somemachine.python.org'
Leak: 0x10171c0c0 size=192 zone: DefaultMallocZone_0x1002f7000
0x31898130 0x0609300b 0x06045503 0x53550213 0..1.0...U....US
0x0f301131 0x04550306 0x44081308 0x77616c65 1.0...U....Delaw
0x31657261 0x06113013 0x07045503 0x69570a13 are1.0...U....Wi
0x6e696d6c 0x6e6f7467 0x21302331 0x04550306 lmington1#0!..U.
0x501a130a 0x6f687479 0x6f53206e 0x61777466 ...Python Softwa
0x46206572 0x646e756f 0x6f697461 0x300c316e re Foundation1.0
0x5503060a 0x03130b04 0x314c5353 0x061d301f ...U....SSL1.0..
0x03045503 0x6f731613 0x616d656d 0x6e696863 .U....somemachin
...
Leak: 0x10171e7a0 size=192 zone: DefaultMallocZone_0x1002f7000
0x31898130 0x0609300b 0x06045503 0x53550213 0..1.0...U....US
0x0f301131 0x04550306 0x44081308 0x77616c65 1.0...U....Delaw
0x31657261 0x06113013 0x07045503 0x69570a13 are1.0...U....Wi
0x6e696d6c 0x6e6f7467 0x21302331 0x04550306 lmington1#0!..U.
0x501a130a 0x6f687479 0x6f53206e 0x61777466 ...Python Softwa
0x46206572 0x646e756f 0x6f697461 0x300c316e re Foundation1.0
0x5503060a 0x03130b04 0x314c5353 0x061d301f ...U....SSL1.0..
0x03045503 0x6f731613 0x616d656d 0x6e696863 .U....somemachin
...

[mdickinson]

From a bit of experimentation, ssl._ssl._test_decode_cert seems to be the call that's leaking. I haven't studied the source to see if I can pinpoint the cause yet.

[mdickinson]

The fix turned out to be as simple as adding a single X509_free call to _test_decode_cert.

Fixed in revisions r83677 (py3k), r83679 (release31-maint), r83680 (release27-maint) and r83686 (release26-maint). [The last with Barry's approval.]