subprocess_fork_exec leaks memory when extra_groups are supplied

[tiran]

BPO	40955
Nosy	@gpshead, @tiran, @koobs, @miss-islington
PRs	bpo-40955: Fix memory leak in subprocess module #20825 [3.9] bpo-40955: Fix memory leak in subprocess module (GH-20825) #20831 [3.8] bpo-40955: Fix memory leak in subprocess module (GH-20825) #20832 [3.7] bpo-40955: Fix memory leak in subprocess module (GH-20825) #20833

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

Show more details

GitHub fields:

assignee = None
closed_at = <Date 2020-06-12.17:09:12.793>
created_at = <Date 2020-06-12.09:54:50.526>
labels = ['extension-modules', '3.9', '3.10', 'performance']
title = 'subprocess_fork_exec leaks memory when extra_groups are supplied'
updated_at = <Date 2020-06-12.17:09:12.791>
user = 'https://github.com/tiran'

bugs.python.org fields:

activity = <Date 2020-06-12.17:09:12.791>
actor = 'christian.heimes'
assignee = 'none'
closed = True
closed_date = <Date 2020-06-12.17:09:12.793>
closer = 'christian.heimes'
components = ['Extension Modules']
creation = <Date 2020-06-12.09:54:50.526>
creator = 'christian.heimes'
dependencies = []
files = []
hgrepos = []
issue_num = 40955
keywords = ['patch']
message_count = 4.0
messages = ['371346', '371392', '371396', '371397']
nosy_count = 4.0
nosy_names = ['gregory.p.smith', 'christian.heimes', 'koobs', 'miss-islington']
pr_nums = ['20825', '20831', '20832', '20833']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'resource usage'
url = 'https://bugs.python.org/issue40955'
versions = ['Python 3.9', 'Python 3.10']

[tiran]

asan has detected a minor memory leak in subprocess_fork_exec:

Direct leak of 8 byte(s) in 1 object(s) allocated from:
#0 0x7f008bf19667 in __interceptor_malloc (/lib64/libasan.so.6+0xb0667)
#1 0x7f007a0bee4a in subprocess_fork_exec /home/heimes/dev/python/cpython/Modules/_posixsubprocess.c:774
#2 0xe0305b in cfunction_call Objects/methodobject.c:546
#3 0x4bdd0c in _PyObject_MakeTpCall Objects/call.c:191
#4 0x462fd0 in _PyObject_VectorcallTstate Include/cpython/abstract.h:112
#5 0x462fd0 in _PyObject_VectorcallTstate Include/cpython/abstract.h:99
#6 0x462fd0 in PyObject_Vectorcall Include/cpython/abstract.h:123
#7 0x462fd0 in call_function Python/ceval.c:5110
#8 0x462fd0 in _PyEval_EvalFrameDefault Python/ceval.c:3510
#9 0x8c1c1d in _PyEval_EvalFrame Include/internal/pycore_ceval.h:40
#10 0x8c1c1d in _PyEval_EvalCode Python/ceval.c:4365

[miss-islington]

New changeset 0d3350d by Christian Heimes in branch 'master':
bpo-40955: Fix memory leak in subprocess module (GH-20825)
0d3350d

[miss-islington]

New changeset ee3f7fe by Miss Islington (bot) in branch '3.9':
bpo-40955: Fix memory leak in subprocess module (GH-20825)
ee3f7fe

[tiran]

3.8 and 3.7 don't have the code path and are not affected.