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Segmentation fault in asyncio #82966

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Segmentation fault in asyncio#82966
Labels
3.7 (EOL)end of life3.8 (EOL)end of life3.9 (EOL)end of lifetopic-asynciotype-crashA hard crash of the interpreter, possibly with a core dump

Description

@akayunov
akayunov
mannequin
opened on Nov 13, 2019
BPO 38785
Nosy @vstinner, @asvetlov, @1st1, @miss-islington, @akayunov
PRs
  • bpo-38785: Prevent asyncio from crashing  #17144
  • [3.8] bpo-38785: Prevent asyncio from crashing (GH-17144) #17147
  • [3.7] bpo-38785: Prevent asyncio from crashing (GH-17144) #17148
    		•
    Files
  • scratch_15.py
    		•

    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 2019-11-13.21:55:19.610>
created_at = <Date 2019-11-13.08:34:09.900>
labels = ['3.7', '3.8', '3.9', 'type-crash', 'expert-asyncio']
title = 'Segmentation fault in asyncio'
updated_at = <Date 2019-11-13.21:55:19.604>
user = 'https://github.com/akayunov'

    bugs.python.org fields:

    activity = <Date 2019-11-13.21:55:19.604>
actor = 'asvetlov'
assignee = 'none'
closed = True
closed_date = <Date 2019-11-13.21:55:19.610>
closer = 'asvetlov'
components = ['asyncio']
creation = <Date 2019-11-13.08:34:09.900>
creator = 'akayunov'
dependencies = []
files = ['48712']
hgrepos = []
issue_num = 38785
keywords = ['patch']
message_count = 8.0
messages = ['356523', '356524', '356526', '356527', '356528', '356557', '356559', '356560']
nosy_count = 5.0
nosy_names = ['vstinner', 'asvetlov', 'yselivanov', 'miss-islington', 'akayunov']
pr_nums = ['17144', '17147', '17148']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'crash'
url = 'https://bugs.python.org/issue38785'
versions = ['Python 3.7', 'Python 3.8', 'Python 3.9']

    Activity

    1. akayunov commented on Nov 13, 2019

      @akayunov
      akayunovmannequin
      on Nov 13, 2019
      MannequinAuthor

      Get Segmentation fault on run script in attachment.

    2. akayunov
      added
      3.7 (EOL)end of life
      topic-asyncio
      type-crashA hard crash of the interpreter, possibly with a core dump
      on Nov 13, 2019

    3. akayunov commented on Nov 13, 2019

      @akayunov
      akayunovmannequin
      on Nov 13, 2019
      MannequinAuthor

      Get seg fault on running script in attachment:

      root@fake:/opt/securisync/be# python3.7 scratch_15.py
      In tratata before
      In tratata2 before
      Segmentation fault

    4. asvetlov commented on Nov 13, 2019

      @asvetlov
      asvetlov
      on Nov 13, 2019
      Contributor

      Thanks for the report!
      I would say that deriving from the future class without calling super().__init__() is an error.
      After fixing this the snippet raises expected "RuntimeError: yield was used instead of yield from in task" error.

    5. vstinner commented on Nov 13, 2019

      @vstinner
      vstinner
      on Nov 13, 2019
      Member

      The crash occurs in _asyncio_Future_get_loop():

      (gdb) frame
      #0 0x00007fffea2fe689 in _Py_INCREF (op=0x0) at ./Include/object.h:459
      459 op->ob_refcnt++;

      (gdb) up
      #1 0x00007fffea301b14 in _asyncio_Future_get_loop_impl (self=0x7fffea2615f0)
      at /home/vstinner/python/master/Modules/_asynciomodule.c:1094
      1094 Py_INCREF(self->fut_loop);

      (gdb) p self->fut_loop
      $1 = 0x0

      (gdb) where
      #0 0x00007fffea2fe689 in _Py_INCREF (op=0x0) at ./Include/object.h:459
      #1 0x00007fffea301b14 in _asyncio_Future_get_loop_impl (self=0x7fffea2615f0)
      at /home/vstinner/python/master/Modules/_asynciomodule.c:1094
      #2 0x00007fffea2fef01 in _asyncio_Future_get_loop (self=0x7fffea2615f0,
      _unused_ignored=0x0)
      at /home/vstinner/python/master/Modules/clinic/_asynciomodule.c.h:252
      #3 0x0000000000645364 in cfunction_vectorcall_NOARGS (
      func=<built-in method get_loop of Qwe2 object at remote 0x7fffea2615f0>,
      args=0x0, nargsf=0, kwnames=0x0) at Objects/methodobject.c:424
      #4 0x000000000042f8d1 in _PyObject_VectorcallTstate (tstate=0x81ae00,
      callable=<built-in method get_loop of Qwe2 object at remote 0x7fffea2615f0>, args=0x0, nargsf=0, kwnames=0x0) at ./Include/cpython/abstract.h:111
      #5 0x000000000042f930 in _PyObject_Vectorcall (
      callable=<built-in method get_loop of Qwe2 object at remote 0x7fffea2615f0>, args=0x0, nargsf=0, kwnames=0x0) at ./Include/cpython/abstract.h:120
      #6 0x000000000042f988 in _PyObject_CallNoArg (
      func=<built-in method get_loop of Qwe2 object at remote 0x7fffea2615f0>)
      at ./Include/cpython/abstract.h:148
      #7 0x000000000042fc57 in PyObject_CallNoArgs (
      func=<built-in method get_loop of Qwe2 object at remote 0x7fffea2615f0>)
      at Objects/call.c:83
      #8 0x00007fffea2ffc16 in get_future_loop (
      fut=<Qwe2(value=0) at remote 0x7fffea2615f0>)
      --Type <RET> for more, q to quit, c to continue without paging--q
      Quit

      (gdb) py-bt
Traceback (most recent call first):
  <built-in method get_loop of Qwe2 object at remote 0x7fffea2615f0>
  <built-in method run of Context object at remote 0x7fffea215170>
  File "/home/vstinner/python/master/Lib/asyncio/events.py", line 81, in _run
    self._context.run(self._callback, *self._args)
  File "/home/vstinner/python/master/Lib/asyncio/base_events.py", line 2641, in _run_once
  File "/home/vstinner/python/master/Lib/asyncio/base_events.py", line 1101, in run_forever
    await waiter
  File "/home/vstinner/python/master/Lib/asyncio/base_events.py", line 621, in run_until_complete
    self.run_forever()
  File "/home/vstinner/python/master/Lib/asyncio/runners.py", line 299, in run
  File "/home/vstinner/python/master/scratch_15.py", line 56, in <module>
    asyncio.run(main())

    6. asvetlov commented on Nov 13, 2019

      @asvetlov
      asvetlov
      on Nov 13, 2019
      Contributor

      Looks like get_future_loop() function misses ENSURE_FUTURE_ALIVE macro call.

    7. miss-islington commented on Nov 13, 2019

      @miss-islington
      miss-islington
      on Nov 13, 2019
      Contributor

      New changeset dad6be5 by Miss Islington (bot) (Andrew Svetlov) in branch 'master':
      bpo-38785: Prevent asyncio from crashing (GH-17144)
      dad6be5

    8. miss-islington commented on Nov 13, 2019

      @miss-islington
      miss-islington
      on Nov 13, 2019
      Contributor

      New changeset 87b4d39 by Miss Islington (bot) in branch '3.7':
      bpo-38785: Prevent asyncio from crashing (GH-17144)
      87b4d39

    9. miss-islington commented on Nov 13, 2019

      @miss-islington
      miss-islington
      on Nov 13, 2019
      Contributor

      New changeset 694c03f by Miss Islington (bot) in branch '3.8':
      bpo-38785: Prevent asyncio from crashing (GH-17144)
      694c03f

    10. asvetlov
      added
      3.8 (EOL)end of life
      3.9 (EOL)end of life
      on Nov 13, 2019
    11. asvetlov
      closed this as completedon Nov 13, 2019
    12. ezio-melotti
      transferred this issue fromon Apr 10, 2022
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