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Base 85 encoding initialization race condition #83249

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drmonkeysee mannequin opened this issue Dec 16, 2019 · 4 comments
Closed

Base 85 encoding initialization race condition #83249

drmonkeysee mannequin opened this issue Dec 16, 2019 · 4 comments
Labels
3.8 only security fixes 3.9 only security fixes 3.10 only security fixes stdlib Python modules in the Lib dir type-crash A hard crash of the interpreter, possibly with a core dump

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@drmonkeysee
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drmonkeysee mannequin commented Dec 16, 2019

BPO 39068
Nosy @serhiy-storchaka, @miss-islington, @drmonkeysee
PRs
  • bpo-39068 guard _b85chars2 initialization #17627
  • [3.9] bpo-39068: Fix race condition in base64 (GH-17627) #24020
  • [3.8] bpo-39068: Fix race condition in base64 (GH-17627) #24022
  • [3.9] bpo-39068: Fix race condition in base64 (GH-17627) #24051
    		•

    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 = None
closed_at = <Date 2021-01-01.20:46:37.998>
created_at = <Date 2019-12-16.17:55:04.510>
labels = ['3.8', '3.10', 'library', '3.9', 'type-crash']
title = 'Base 85 encoding initialization race condition'
updated_at = <Date 2021-01-01.20:46:37.997>
user = 'https://github.com/drmonkeysee'

    bugs.python.org fields:

    activity = <Date 2021-01-01.20:46:37.997>
actor = 'serhiy.storchaka'
assignee = 'none'
closed = True
closed_date = <Date 2021-01-01.20:46:37.998>
closer = 'serhiy.storchaka'
components = ['Library (Lib)']
creation = <Date 2019-12-16.17:55:04.510>
creator = 'drmonkeysee'
dependencies = []
files = []
hgrepos = []
issue_num = 39068
keywords = ['patch']
message_count = 4.0
messages = ['358495', '384107', '384190', '384205']
nosy_count = 3.0
nosy_names = ['serhiy.storchaka', 'miss-islington', 'drmonkeysee']
pr_nums = ['17627', '24020', '24022', '24051']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'crash'
url = 'https://bugs.python.org/issue39068'
versions = ['Python 3.8', 'Python 3.9', 'Python 3.10']
    @drmonkeysee
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    drmonkeysee mannequin commented Dec 16, 2019

    Under multi-threading scenarios a race condition may occur where a thread sees an initialized _b85chars table but an uninitialized _b85chars2 table due to the guard only checking the first table.

    This causes an exception like:

      File "/usr/lib/python3.6/base64.py", line 434, in b85encode
    return _85encode(b, _b85chars, _b85chars2, pad),
  File "/usr/lib/python3.6/base64.py", line 294, in _85encode
    for word in words],
  File "/usr/lib/python3.6/base64.py", line 294, in <listcomp>
    for word in words],
 "TypeError: 'NoneType' object is not subscriptable

    @drmonkeysee drmonkeysee mannequin added stdlib Python modules in the Lib dir type-crash A hard crash of the interpreter, possibly with a core dump labels Dec 16, 2019
    @drmonkeysee drmonkeysee mannequin changed the title Base 85 encoding initialization race conditiong Base 85 encoding initialization race condition Dec 16, 2019
    @drmonkeysee drmonkeysee mannequin changed the title Base 85 encoding initialization race conditiong Base 85 encoding initialization race condition Dec 16, 2019
    @serhiy-storchaka
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    New changeset 9655434 by Brandon Stansbury in branch 'master':
    bpo-39068: Fix race condition in base64 (GH-17627)
    9655434

    @serhiy-storchaka
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    New changeset b863607 by Serhiy Storchaka in branch '3.8':
    [3.8] bpo-39068: Fix race condition in base64 (GH-17627) (GH-24022)
    b863607

    @miss-islington
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    New changeset 0d6e407 by Miss Islington (bot) in branch '3.9':
    bpo-39068: Fix race condition in base64 (GH-17627)
    0d6e407

    @serhiy-storchaka serhiy-storchaka added 3.8 only security fixes 3.9 only security fixes 3.10 only security fixes labels Jan 1, 2021
    @serhiy-storchaka serhiy-storchaka added 3.8 only security fixes 3.9 only security fixes 3.10 only security fixes labels Jan 1, 2021
    @ezio-melotti ezio-melotti transferred this issue from another repository Apr 10, 2022
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