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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 (EOL) end of life 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 (EOL) end of life 3.9 only security fixes 3.10 only security fixes labels Jan 1, 2021
    @serhiy-storchaka serhiy-storchaka added 3.8 (EOL) end of life 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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