gh-140406: Fix memory leak upon `__hash__` returning a non-integer by ZeroIntensity · Pull Request #140411 · python/cpython

ZeroIntensity · 2025-10-21T10:52:38Z

Issue: Memory leak when object.__hash__ returns a non-int value #140406

kumaraditya303 · 2025-10-21T10:55:41Z

Lib/test/test_hash.py

+                return 1.0
+
+        for _ in range(100):
+            with self.assertRaises(TypeError):


The ref leak checker should catch it even in one iteration, is 100 needed here?

It's a very tiny leak, so I wasn't sure if it would be caught. I don't mind removing it.

test_hash in test_builtin is also a good place. It already contains similar tests (TypeErrors and classes with custom __hash__).

Good idea, I moved it to test_builtin.

serhiy-storchaka

I just created a similar patch, but you were the first.

serhiy-storchaka · 2025-10-21T11:00:49Z

Lib/test/test_hash.py

+                return 1.0
+
+        for _ in range(100):
+            with self.assertRaises(TypeError):


test_hash in test_builtin is also a good place. It already contains similar tests (TypeErrors and classes with custom __hash__).

serhiy-storchaka · 2025-10-21T11:02:41Z

Objects/typeobject.c

        return PyObject_HashNotImplemented(self);
    }
    if (!PyLong_Check(res)) {
+        Py_DECREF(res);


I suggest to move this line below PyErr_SetString(). Later, it can be used to format a better error message.

I think we should do that in a different PR, where we change the error message. I generally like to call Py_DECREF before PyErr* functions to protect against badly crafted destructors that break the exception state. But, if you feel strongly about this, I'm also fine with moving it.

I do not feel strongly about this. It would just make the future diff a little bit smaller, and git blame would show your commit instead of the following commit.
In general, I prefer to call Py_DECREF before PyErr* functions too.

serhiy-storchaka

LGTM. 👍

ZeroIntensity · 2025-10-21T11:11:28Z

I just created a similar patch, but you were the first.

Sorry! I'd have let you go for it if I had known you were working on it.

miss-islington-app · 2025-10-21T12:10:05Z

Thanks @ZeroIntensity for the PR 🌮🎉.. I'm working now to backport this PR to: 3.13, 3.14.
🐍🍒⛏🤖 I'm not a witch! I'm not a witch!

…ger (pythonGH-140411) (cherry picked from commit 71db05a) Co-authored-by: Peter Bierma <zintensitydev@gmail.com>

miss-islington-app · 2025-10-21T12:10:13Z

Sorry, @ZeroIntensity, I could not cleanly backport this to 3.13 due to a conflict.
Please backport using cherry_picker on command line.

cherry_picker 71db05a12d9953a96f809d84b4d0d452a464e431 3.13

bedevere-app · 2025-10-21T12:10:19Z

GH-140417 is a backport of this pull request to the 3.14 branch.

…eger (GH-140411) (GH-140417) gh-140406: Fix memory leak upon `__hash__` returning a non-integer (GH-140411) (cherry picked from commit 71db05a) Co-authored-by: Peter Bierma <zintensitydev@gmail.com>

bedevere-bot · 2025-10-21T12:49:22Z

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot ARM64 macOS 3.14 (tier-2) has failed when building commit c0f0eca.

What do you need to do:

Don't panic.
Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
Go to the page of the buildbot that failed (https://buildbot.python.org/#/builders/1772/builds/614) and take a look at the build logs.
Check if the failure is related to this commit (c0f0eca) or if it is a false positive.
If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#/builders/1772/builds/614

Failed tests:

test_urllib2net

Failed subtests:

test_ftp_no_timeout - test.test_urllib2net.TimeoutTest.test_ftp_no_timeout
test_ftp_default_timeout - test.test_urllib2net.TimeoutTest.test_ftp_default_timeout

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 363, in test_ftp_no_timeout
    u = _urlopen_with_retry(self.FTP_HOST, timeout=None)
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 28, in wrapped
    return _retry_thrice(func, exc, *args, **kwargs)
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 24, in _retry_thrice
    raise last_exc
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 20, in _retry_thrice
    return func(*args, **kwargs)
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/urllib/request.py", line 187, in urlopen
    return opener.open(url, data, timeout)
           ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/urllib/request.py", line 487, in open
    response = self._open(req, data)
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/urllib/request.py", line 504, in _open
    result = self._call_chain(self.handle_open, protocol, protocol +
                              '_open', req)
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/urllib/request.py", line 464, in _call_chain
    result = func(*args)
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/urllib/request.py", line 1556, in ftp_open
    raise URLError(f"ftp error: {exp}") from exp
urllib.error.URLError: <urlopen error ftp error: [Errno 60] Operation timed out>


Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 22, in _retry_thrice
    last_exc = e
ResourceWarning: unclosed <socket.socket fd=7, family=2, type=1, proto=6, laddr=('192.168.0.101', 59738), raddr=('68.183.26.59', 21)>
Warning -- Unraisable exception
Exception ignored while finalizing socket <socket.socket fd=8, family=2, type=1, proto=6, laddr=('192.168.0.101', 59815), raddr=('68.183.26.59', 21)>:
Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 22, in _retry_thrice
    last_exc = e
ResourceWarning: unclosed <socket.socket fd=8, family=2, type=1, proto=6, laddr=('192.168.0.101', 59815), raddr=('68.183.26.59', 21)>
ERROR


Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/support/__init__.py", line 847, in gc_collect
    gc.collect()
ResourceWarning: unclosed <socket.socket fd=6, family=2, type=1, proto=6, laddr=('192.168.0.101', 59572), raddr=('68.183.26.59', 21)>
Warning -- Unraisable exception
Exception ignored while finalizing socket <socket.socket fd=7, family=2, type=1, proto=6, laddr=('192.168.0.101', 59983), raddr=('68.183.26.59', 21)>:
Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/support/__init__.py", line 847, in gc_collect
    gc.collect()
ResourceWarning: unclosed <socket.socket fd=7, family=2, type=1, proto=6, laddr=('192.168.0.101', 59983), raddr=('68.183.26.59', 21)>
Warning -- Unraisable exception
Exception ignored while finalizing socket <socket.socket fd=8, family=2, type=1, proto=6, laddr=('192.168.0.101', 60078), raddr=('68.183.26.59', 21)>:
Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/support/__init__.py", line 847, in gc_collect
    gc.collect()
ResourceWarning: unclosed <socket.socket fd=8, family=2, type=1, proto=6, laddr=('192.168.0.101', 60078), raddr=('68.183.26.59', 21)>


Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/support/__init__.py", line 847, in gc_collect
    gc.collect()
ResourceWarning: unclosed <socket.socket fd=7, family=2, type=1, proto=6, laddr=('192.168.0.101', 62198), raddr=('68.183.26.59', 21)>
Warning -- Unraisable exception
Exception ignored while finalizing socket <socket.socket fd=8, family=2, type=1, proto=6, laddr=('192.168.0.101', 62205), raddr=('68.183.26.59', 21)>:
Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/support/__init__.py", line 847, in gc_collect
    gc.collect()
ResourceWarning: unclosed <socket.socket fd=8, family=2, type=1, proto=6, laddr=('192.168.0.101', 62205), raddr=('68.183.26.59', 21)>


Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 351, in test_ftp_default_timeout
    u = _urlopen_with_retry(self.FTP_HOST)
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 28, in wrapped
    return _retry_thrice(func, exc, *args, **kwargs)
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 24, in _retry_thrice
    raise last_exc
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 20, in _retry_thrice
    return func(*args, **kwargs)
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/urllib/request.py", line 187, in urlopen
    return opener.open(url, data, timeout)
           ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/urllib/request.py", line 487, in open
    response = self._open(req, data)
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/urllib/request.py", line 504, in _open
    result = self._call_chain(self.handle_open, protocol, protocol +
                              '_open', req)
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/urllib/request.py", line 464, in _call_chain
    result = func(*args)
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/urllib/request.py", line 1556, in ftp_open
    raise URLError(f"ftp error: {exp}") from exp
urllib.error.URLError: <urlopen error ftp error: [Errno 60] Operation timed out>


Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 22, in _retry_thrice
    last_exc = e
ResourceWarning: unclosed <socket.socket fd=8, family=2, type=1, proto=6, laddr=('192.168.0.101', 62200), raddr=('68.183.26.59', 21)>
Warning -- Unraisable exception
Exception ignored while finalizing socket <socket.socket fd=9, family=2, type=1, proto=6, laddr=('192.168.0.101', 62203), raddr=('68.183.26.59', 21)>:
Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 22, in _retry_thrice
    last_exc = e
ResourceWarning: unclosed <socket.socket fd=9, family=2, type=1, proto=6, laddr=('192.168.0.101', 62203), raddr=('68.183.26.59', 21)>
ERROR


Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 22, in _retry_thrice
    last_exc = e
ResourceWarning: unclosed <socket.socket fd=6, family=2, type=1, proto=6, laddr=('192.168.0.101', 59387), raddr=('68.183.26.59', 21)>
Warning -- Unraisable exception
Exception ignored while finalizing socket <socket.socket fd=7, family=2, type=1, proto=6, laddr=('192.168.0.101', 59504), raddr=('68.183.26.59', 21)>:
Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 22, in _retry_thrice
    last_exc = e
ResourceWarning: unclosed <socket.socket fd=7, family=2, type=1, proto=6, laddr=('192.168.0.101', 59504), raddr=('68.183.26.59', 21)>
ERROR


Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/urllib/request.py", line 1546, in ftp_open
    fp, retrlen = fw.retrfile(file, type)
                  ~~~~~~~~~~~^^^^^^^^^^^^
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/urllib/request.py", line 1826, in retrfile
    conn, retrlen = self.ftp.ntransfercmd(cmd)
                    ~~~~~~~~~~~~~~~~~~~~~^^^^^
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/ftplib.py", line 354, in ntransfercmd
    conn = socket.create_connection((host, port), self.timeout,
                                    source_address=self.source_address)
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/socket.py", line 870, in create_connection
    raise exceptions[0]
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/socket.py", line 855, in create_connection
    sock.connect(sa)
    ~~~~~~~~~~~~^^^^
TimeoutError: [Errno 60] Operation timed out


Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 22, in _retry_thrice
    last_exc = e
ResourceWarning: unclosed <socket.socket fd=7, family=2, type=1, proto=6, laddr=('192.168.0.101', 62194), raddr=('68.183.26.59', 21)>
Warning -- Unraisable exception
Exception ignored while finalizing socket <socket.socket fd=8, family=2, type=1, proto=6, laddr=('192.168.0.101', 62196), raddr=('68.183.26.59', 21)>:
Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.14.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_urllib2net.py", line 22, in _retry_thrice
    last_exc = e
ResourceWarning: unclosed <socket.socket fd=8, family=2, type=1, proto=6, laddr=('192.168.0.101', 62196), raddr=('68.183.26.59', 21)>
ERROR

bedevere-app · 2025-10-22T00:46:19Z

GH-140441 is a backport of this pull request to the 3.13 branch.

…ger (pythonGH-140411) (cherry picked from commit 71db05a)

…on-integer (pythonGH-140411) (cherry picked from commit 71db05a) Co-authored-by: Peter Bierma <zintensitydev@gmail.com>

…eger (GH-140411) (GH-140441) * gh-140406: Fix memory leak upon `__hash__` returning a non-integer (GH-140411) (cherry picked from commit 71db05a)

…ger (pythonGH-140411)

ZeroIntensity added 3 commits October 21, 2025 06:47

Fix memory leak upon __hash__ returning a non-integer.

b1013fe

Add a test case.

ed017f0

Add blurb.

9f89372

ZeroIntensity requested a review from markshannon as a code owner October 21, 2025 10:52

bedevere-app bot mentioned this pull request Oct 21, 2025

Memory leak when object.__hash__ returns a non-int value #140406

Closed

bedevere-app bot added the awaiting core review label Oct 21, 2025

ZeroIntensity added needs backport to 3.13 bugs and security fixes needs backport to 3.14 bugs and security fixes labels Oct 21, 2025

kumaraditya303 reviewed Oct 21, 2025

View reviewed changes

Remove unnecessary loop.

1b96db7

serhiy-storchaka reviewed Oct 21, 2025

View reviewed changes

serhiy-storchaka approved these changes Oct 21, 2025

View reviewed changes

bedevere-app bot added awaiting merge and removed awaiting core review labels Oct 21, 2025

Move test to test_builtin.

5754822

kumaraditya303 approved these changes Oct 21, 2025

View reviewed changes

ZeroIntensity merged commit 71db05a into python:main Oct 21, 2025
45 checks passed

ZeroIntensity deleted the hash-leak branch October 21, 2025 12:10

bedevere-app bot removed the awaiting merge label Oct 21, 2025

miss-islington-app bot assigned ZeroIntensity Oct 21, 2025

bedevere-app bot removed the needs backport to 3.14 bugs and security fixes label Oct 21, 2025

bedevere-app bot removed the needs backport to 3.13 bugs and security fixes label Oct 22, 2025

ZeroIntensity added a commit to ZeroIntensity/cpython that referenced this pull request Oct 22, 2025

pythongh-140406: Fix memory leak upon __hash__ returning a non-inte…

649986b

…ger (pythonGH-140411) (cherry picked from commit 71db05a)

StanFromIreland pushed a commit to StanFromIreland/cpython that referenced this pull request Dec 6, 2025

pythongh-140406: Fix memory leak upon __hash__ returning a non-inte…

6a88b06

…ger (pythonGH-140411)

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⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

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