GeezerVison

The World Wide Web, restored to 800 pixels of glory.

GeezerVison is showing github.com — gh-140067: Fix memory leak in sub-interpreter creation by ashm-dev · Pull Request #140111 · python/cpython

Conversation

ashm-dev commented Oct 14, 2025 •

edited by bedevere-app Bot

Loading

Uh oh!

There was an error while loading. Please reload this page.

Copy link

Copy Markdown

Contributor

This patch fixes a memory leak detected by AddressSanitizer during subinterpreter creation.
The original allocation pointer is now stored before the aligned memory block, removing
the need for the _malloced field in PyInterpreterState.

Thanks to @kumaraditya303 for highlighting the pointer overwrite issue.

Fixes #140067

Issue: Memory leak in test_sys with subinterpreters creation (AddressSanitizer detection) #140067

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.

All reactions


          bpo-140067: Fix memory leak in subinterpreter creation (remove redundant

595adea

malloced pointer)

ashm-dev requested review from ZeroIntensity and ericsnowcurrently as code owners

October 14, 2025 14:03

bedevere-app Bot added the awaiting review label

Oct 14, 2025


          add blurb

0fd2715

StanFromIreland changed the title ~~bpo-140067: Fix memory leak in subinterpreter creation (remove redundant~~ gh-140067: Fix memory leak in subinterpreter creation (remove redundant

Oct 14, 2025

bedevere-app Bot mentioned this pull request

Oct 14, 2025

Memory leak in test_sys with subinterpreters creation (AddressSanitizer detection) #140067

Closed


          Merge branch 'main' into pythongh-140067

b96102b

kumaraditya303 changed the title ~~gh-140067: Fix memory leak in subinterpreter creation (remove redundant~~ gh-140067: Fix memory leak in sub-interpreter creation

Oct 14, 2025

kumaraditya303 reviewed

Oct 14, 2025

View reviewed changes

Comment thread

Misc/NEWS.d/next/Core_and_Builtins/2025-10-14-17-07-37.gh-issue-140067.ID2gOm.rst Resolved

Uh oh!

There was an error while loading. Please reload this page.

kumaraditya303 reviewed

Oct 14, 2025

View reviewed changes

Comment thread

Python/pystate.c Resolved

Uh oh!

There was an error while loading. Please reload this page.

kumaraditya303 reviewed

Oct 14, 2025

View reviewed changes

Comment thread

Python/pystate.c Resolved

Uh oh!

There was an error while loading. Please reload this page.

ashm-dev and others added 3 commits

October 14, 2025 17:16


          Update Misc/NEWS.d/next/Core_and_Builtins/2025-10-14-17-07-37.gh-issu…

e9c6735

…e-140067.ID2gOm.rst

Co-authored-by: Kumar Aditya <[email protected]>


          Update Python/pystate.c

0afd99e

Co-authored-by: Kumar Aditya <[email protected]>


          Update Python/pystate.c

47fef02

Co-authored-by: Kumar Aditya <[email protected]>

kumaraditya303 commented Oct 14, 2025

Copy link

Copy Markdown

Contributor

On main without fix:

Using random seed: 1178707616
0:00:00 load avg: 0.00 Run 1 test sequentially in a single process
0:00:00 load avg: 0.00 [1/1] test_sys
0:00:15 load avg: 0.30 [1/1] test_sys passed

== Tests result: SUCCESS ==

1 test OK.

Total duration: 15.3 sec
Total tests: run=92 skipped=7
Total test files: run=1/1
Result: SUCCESS

=================================================================
==72608==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 4290637 byte(s) in 19 object(s) allocated from:
    #0 0x55ccf021119d in calloc (/home/realkumaraditya/cpython/python+0x32f19d) (BuildId: 8c0c0e48d6c92676ff9a5253a45afb26c8d18926)
    #1 0x55ccf0549d3e in _PyMem_DebugRawAlloc /home/realkumaraditya/cpython/Objects/obmalloc.c:2884:24
    #2 0x55ccf0549d3e in _PyMem_DebugRawCalloc /home/realkumaraditya/cpython/Objects/obmalloc.c:2929:12
    #3 0x55ccf091d6d5 in alloc_interpreter /home/realkumaraditya/cpython/Python/pystate.c:462:17
    #4 0x55ccf091d6d5 in _PyInterpreterState_New /home/realkumaraditya/cpython/Python/pystate.c:660:18
    #5 0x55ccf08d5f30 in new_interpreter /home/realkumaraditya/cpython/Python/pylifecycle.c:2425:14
    #6 0x55ccf08d5cb2 in Py_NewInterpreterFromConfig /home/realkumaraditya/cpython/Python/pylifecycle.c:2521:12
    #7 0x55ccf080f6a8 in _PyXI_NewInterpreter /home/realkumaraditya/cpython/Python/crossinterp.c:3204:23
    #8 0x7f4cbc4dc62f in _interpreters_create_impl /home/realkumaraditya/cpython/./Modules/_interpretersmodule.c:880:13
    #9 0x7f4cbc4dc62f in _interpreters_create /home/realkumaraditya/cpython/./Modules/clinic/_interpretersmodule.c.h:91:20
    #10 0x55ccf03fafc2 in _PyObject_VectorcallTstate /home/realkumaraditya/cpython/./Include/internal/pycore_call.h:169:11
    #11 0x55ccf0783a7f in _PyEval_EvalFrameDefault /home/realkumaraditya/cpython/Python/generated_cases.c.h:3188:35
    #12 0x55ccf075c6e7 in _PyEval_EvalFrame /home/realkumaraditya/cpython/./Include/internal/pycore_ceval.h:121:16
    #13 0x55ccf075c6e7 in _PyEval_Vector /home/realkumaraditya/cpython/Python/ceval.c:2001:12
    #14 0x55ccf0406d12 in _PyObject_VectorcallTstate /home/realkumaraditya/cpython/./Include/internal/pycore_call.h:169:11
    #15 0x55ccf0404631 in method_vectorcall /home/realkumaraditya/cpython/Objects/classobject.c:95:18
    #16 0x55ccf077790d in _PyEval_EvalFrameDefault /home/realkumaraditya/cpython/Python/generated_cases.c.h:2616:32
    #17 0x55ccf075c6e7 in _PyEval_EvalFrame /home/realkumaraditya/cpython/./Include/internal/pycore_ceval.h:121:16
    #18 0x55ccf075c6e7 in _PyEval_Vector /home/realkumaraditya/cpython/Python/ceval.c:2001:12
    #19 0x55ccf03fb440 in _PyObject_VectorcallDictTstate /home/realkumaraditya/cpython/Objects/call.c:135:15
    #20 0x55ccf03fe1b2 in _PyObject_Call_Prepend /home/realkumaraditya/cpython/Objects/call.c:504:24
    #21 0x55ccf05ade31 in call_method /home/realkumaraditya/cpython/Objects/typeobject.c:3076:19
    #22 0x55ccf03fb9f3 in _PyObject_MakeTpCall /home/realkumaraditya/cpython/Objects/call.c:242:18
    #23 0x55ccf078353d in _PyEval_EvalFrameDefault /home/realkumaraditya/cpython/Python/generated_cases.c.h:4021:35
    #24 0x55ccf075c6e7 in _PyEval_EvalFrame /home/realkumaraditya/cpython/./Include/internal/pycore_ceval.h:121:16
    #25 0x55ccf075c6e7 in _PyEval_Vector /home/realkumaraditya/cpython/Python/ceval.c:2001:12
    #26 0x55ccf0406d12 in _PyObject_VectorcallTstate /home/realkumaraditya/cpython/./Include/internal/pycore_call.h:169:11
    #27 0x55ccf0404631 in method_vectorcall /home/realkumaraditya/cpython/Objects/classobject.c:95:18
    #28 0x55ccf077790d in _PyEval_EvalFrameDefault /home/realkumaraditya/cpython/Python/generated_cases.c.h:2616:32
    #29 0x55ccf075c6e7 in _PyEval_EvalFrame /home/realkumaraditya/cpython/./Include/internal/pycore_ceval.h:121:16
    #30 0x55ccf075c6e7 in _PyEval_Vector /home/realkumaraditya/cpython/Python/ceval.c:2001:12
    #31 0x55ccf03fb440 in _PyObject_VectorcallDictTstate /home/realkumaraditya/cpython/Objects/call.c:135:15
    #32 0x55ccf03fe1b2 in _PyObject_Call_Prepend /home/realkumaraditya/cpython/Objects/call.c:504:24
    #33 0x55ccf05ade31 in call_method /home/realkumaraditya/cpython/Objects/typeobject.c:3076:19
    #34 0x55ccf03fb9f3 in _PyObject_MakeTpCall /home/realkumaraditya/cpython/Objects/call.c:242:18
    #35 0x55ccf078353d in _PyEval_EvalFrameDefault /home/realkumaraditya/cpython/Python/generated_cases.c.h:4021:35
    #36 0x55ccf075c6e7 in _PyEval_EvalFrame /home/realkumaraditya/cpython/./Include/internal/pycore_ceval.h:121:16
    #37 0x55ccf075c6e7 in _PyEval_Vector /home/realkumaraditya/cpython/Python/ceval.c:2001:12

Direct leak of 225823 byte(s) in 1 object(s) allocated from:
    #0 0x55ccf021119d in calloc (/home/realkumaraditya/cpython/python+0x32f19d) (BuildId: 8c0c0e48d6c92676ff9a5253a45afb26c8d18926)
    #1 0x55ccf0549d3e in _PyMem_DebugRawAlloc /home/realkumaraditya/cpython/Objects/obmalloc.c:2884:24
    #2 0x55ccf0549d3e in _PyMem_DebugRawCalloc /home/realkumaraditya/cpython/Objects/obmalloc.c:2929:12
    #3 0x55ccf091d6d5 in alloc_interpreter /home/realkumaraditya/cpython/Python/pystate.c:462:17
    #4 0x55ccf091d6d5 in _PyInterpreterState_New /home/realkumaraditya/cpython/Python/pystate.c:660:18
    #5 0x55ccf08d5f30 in new_interpreter /home/realkumaraditya/cpython/Python/pylifecycle.c:2425:14
    #6 0x55ccf08d5cb2 in Py_NewInterpreterFromConfig /home/realkumaraditya/cpython/Python/pylifecycle.c:2521:12
    #7 0x55ccf080f6a8 in _PyXI_NewInterpreter /home/realkumaraditya/cpython/Python/crossinterp.c:3204:23
    #8 0x7f4cbc4dc62f in _interpreters_create_impl /home/realkumaraditya/cpython/./Modules/_interpretersmodule.c:880:13
    #9 0x7f4cbc4dc62f in _interpreters_create /home/realkumaraditya/cpython/./Modules/clinic/_interpretersmodule.c.h:91:20
    #10 0x55ccf03fafc2 in _PyObject_VectorcallTstate /home/realkumaraditya/cpython/./Include/internal/pycore_call.h:169:11
    #11 0x55ccf078af2d in _PyEval_EvalFrameDefault /home/realkumaraditya/cpython/Python/generated_cases.c.h:2920:35
    #12 0x55ccf075c6e7 in _PyEval_EvalFrame /home/realkumaraditya/cpython/./Include/internal/pycore_ceval.h:121:16
    #13 0x55ccf075c6e7 in _PyEval_Vector /home/realkumaraditya/cpython/Python/ceval.c:2001:12
    #14 0x55ccf0406d12 in _PyObject_VectorcallTstate /home/realkumaraditya/cpython/./Include/internal/pycore_call.h:169:11
    #15 0x55ccf0404631 in method_vectorcall /home/realkumaraditya/cpython/Objects/classobject.c:95:18
    #16 0x55ccf077790d in _PyEval_EvalFrameDefault /home/realkumaraditya/cpython/Python/generated_cases.c.h:2616:32
    #17 0x55ccf075c6e7 in _PyEval_EvalFrame /home/realkumaraditya/cpython/./Include/internal/pycore_ceval.h:121:16
    #18 0x55ccf075c6e7 in _PyEval_Vector /home/realkumaraditya/cpython/Python/ceval.c:2001:12
    #19 0x55ccf03fb440 in _PyObject_VectorcallDictTstate /home/realkumaraditya/cpython/Objects/call.c:135:15
    #20 0x55ccf03fe1b2 in _PyObject_Call_Prepend /home/realkumaraditya/cpython/Objects/call.c:504:24
    #21 0x55ccf05ade31 in call_method /home/realkumaraditya/cpython/Objects/typeobject.c:3076:19
    #22 0x55ccf03fb9f3 in _PyObject_MakeTpCall /home/realkumaraditya/cpython/Objects/call.c:242:18
    #23 0x55ccf078353d in _PyEval_EvalFrameDefault /home/realkumaraditya/cpython/Python/generated_cases.c.h:4021:35
    #24 0x55ccf075c6e7 in _PyEval_EvalFrame /home/realkumaraditya/cpython/./Include/internal/pycore_ceval.h:121:16
    #25 0x55ccf075c6e7 in _PyEval_Vector /home/realkumaraditya/cpython/Python/ceval.c:2001:12
    #26 0x55ccf0406d12 in _PyObject_VectorcallTstate /home/realkumaraditya/cpython/./Include/internal/pycore_call.h:169:11
    #27 0x55ccf0404631 in method_vectorcall /home/realkumaraditya/cpython/Objects/classobject.c:95:18
    #28 0x55ccf077790d in _PyEval_EvalFrameDefault /home/realkumaraditya/cpython/Python/generated_cases.c.h:2616:32
    #29 0x55ccf075c6e7 in _PyEval_EvalFrame /home/realkumaraditya/cpython/./Include/internal/pycore_ceval.h:121:16
    #30 0x55ccf075c6e7 in _PyEval_Vector /home/realkumaraditya/cpython/Python/ceval.c:2001:12
    #31 0x55ccf03fb440 in _PyObject_VectorcallDictTstate /home/realkumaraditya/cpython/Objects/call.c:135:15
    #32 0x55ccf03fe1b2 in _PyObject_Call_Prepend /home/realkumaraditya/cpython/Objects/call.c:504:24
    #33 0x55ccf05ade31 in call_method /home/realkumaraditya/cpython/Objects/typeobject.c:3076:19
    #34 0x55ccf03fb9f3 in _PyObject_MakeTpCall /home/realkumaraditya/cpython/Objects/call.c:242:18
    #35 0x55ccf078353d in _PyEval_EvalFrameDefault /home/realkumaraditya/cpython/Python/generated_cases.c.h:4021:35
    #36 0x55ccf075c6e7 in _PyEval_EvalFrame /home/realkumaraditya/cpython/./Include/internal/pycore_ceval.h:121:16
    #37 0x55ccf075c6e7 in _PyEval_Vector /home/realkumaraditya/cpython/Python/ceval.c:2001:12

SUMMARY: AddressSanitizer: 4516460 byte(s) leaked in 20 allocation(s).

With fix:

Using random seed: 1947560357
0:00:00 load avg: 1.07 Run 1 test sequentially in a single process
0:00:00 load avg: 1.07 [1/1] test_sys
0:00:16 load avg: 1.12 [1/1] test_sys passed

== Tests result: SUCCESS ==

1 test OK.

Total duration: 16.3 sec
Total tests: run=92 skipped=7
Total test files: run=1/1
Result: SUCCESS

All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.

ZeroIntensity reviewed

Oct 14, 2025

View reviewed changes

Comment thread

Include/internal/pycore_interp_structs.h Resolved

Uh oh!

There was an error while loading. Please reload this page.

kumaraditya303 approved these changes

Oct 14, 2025

View reviewed changes

bedevere-app Bot added awaiting merge and removed awaiting review labels

Oct 14, 2025

kumaraditya303 requested a review from ZeroIntensity

October 14, 2025 14:25

ZeroIntensity approved these changes

Oct 14, 2025

View reviewed changes

kumaraditya303 self-assigned this

Oct 14, 2025

kumaraditya303 added interpreter-core

(Objects, Python, Grammar, and Parser dirs)

topic-subinterpreters labels

Oct 14, 2025

kumaraditya303 enabled auto-merge (squash)

October 14, 2025 14:38

kumaraditya303 merged commit 59547a2 into python:main

Oct 14, 2025

4 checks passed

Uh oh!

There was an error while loading. Please reload this page.

bedevere-app Bot removed the awaiting merge label

Oct 14, 2025

ashm-dev deleted the gh-140067 branch

October 14, 2025 14:43

bedevere-app Bot commented Oct 14, 2025

Copy link

Copy Markdown

GH-140118 is a backport of this pull request to the 3.14 branch.

All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.

bedevere-app Bot commented Oct 14, 2025

Copy link

Copy Markdown

GH-140118 is a backport of this pull request to the 3.14 branch.

All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.

kumaraditya303 added a commit to kumaraditya303/cpython that referenced this pull request

Oct 14, 2025


          [3.14] pythongh-140067: Fix memory leak in sub-interpreter creation (p…

a25bab8

…ythonGH-140111)

Fix memory leak in sub-interpreter creation caused by overwriting of the previously used `_malloced` field. Now the pointer is stored in the first word of the memory block to avoid it being overwritten accidentally.
(cherry picked from commit 59547a2)

Co-authored-by: Shamil <[email protected]>
Co-authored-by: Kumar Aditya <[email protected]>

nascheme mentioned this pull request

Oct 14, 2025

TSAN failure with free-threaded build, test_daemon_threads_fatal_error #140138

Closed

ZeroIntensity mentioned this pull request

Oct 14, 2025

[3.14] gh-140067: Fix memory leak in sub-interpreter creation (GH-140111) #140118

Merged

ZeroIntensity added a commit to ZeroIntensity/cpython that referenced this pull request

Oct 14, 2025


          Revert "pythongh-140067: Fix memory leak in sub-interpreter creation (p…

eac1c71

…ython#140111)"

This reverts commit 59547a2.

ZeroIntensity commented Oct 15, 2025

Copy link

Copy Markdown

Member

It seems this broke the TSan CI, see #140138. I have a revert up at #140140.

All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.

kumaraditya303 pushed a commit that referenced this pull request

Oct 15, 2025


          Revert "gh-140067: Fix memory leak in sub-interpreter creation (#140111…

0bcb1c2

…)" (#140140)

This reverts commit 59547a2.

ashm-dev restored the gh-140067 branch

October 15, 2025 07:13

ashm-dev mentioned this pull request

Oct 16, 2025

gh-140138: NOGIL: add atomic owner refcount to PyInterpreterState; finalize on last tstate #140224

Closed

kumaraditya303 added a commit to kumaraditya303/cpython that referenced this pull request

Oct 17, 2025


          pythongh-140067: Fix memory leak in sub-interpreter creation (python#…

a775296

…140111)

Fix memory leak in sub-interpreter creation caused by overwriting of the previously used `_malloced` field. Now the pointer is stored in the first word of the memory block to avoid it being overwritten accidentally. 

Co-authored-by: Kumar Aditya <[email protected]>

kumaraditya303 added a commit that referenced this pull request

Oct 18, 2025


          gh-140067: Fix memory leak in sub-interpreter creation (#140111) (#14…

58c44c2

…0261)

Fix memory leak in sub-interpreter creation caused by overwriting of the previously used `_malloced` field. Now the pointer is stored in the first word of the memory block to avoid it being overwritten accidentally. 

Co-authored-by: Kumar Aditya <[email protected]>

kumaraditya303 added a commit that referenced this pull request

Oct 18, 2025


          [3.14] gh-140067: Fix memory leak in sub-interpreter creation (GH-140111

1d11627

) (#140118)

* [3.14] gh-140067: Fix memory leak in sub-interpreter creation  (GH-140111)

Fix memory leak in sub-interpreter creation caused by overwriting of the previously used `_malloced` field. Now the pointer is stored in the first word of the memory block to avoid it being overwritten accidentally.
(cherry picked from commit 59547a2)

Co-authored-by: Shamil <[email protected]>
Co-authored-by: Kumar Aditya <[email protected]>

StanFromIreland pushed a commit to StanFromIreland/cpython that referenced this pull request

Dec 6, 2025


          pythongh-140067: Fix memory leak in sub-interpreter creation (python#…

247c974

…140111)

Fix memory leak in sub-interpreter creation caused by overwriting of the previously used `_malloced` field. Now the pointer is stored in the first word of the memory block to avoid it being overwritten accidentally. 

Co-authored-by: Kumar Aditya <[email protected]>

StanFromIreland pushed a commit to StanFromIreland/cpython that referenced this pull request

Dec 6, 2025


          Revert "pythongh-140067: Fix memory leak in sub-interpreter creation (p…

01c0ad6

…ython#140111)" (python#140140)

This reverts commit 59547a2.

StanFromIreland pushed a commit to StanFromIreland/cpython that referenced this pull request

Dec 6, 2025


          pythongh-140067: Fix memory leak in sub-interpreter creation (python#…

eab8105

…140111)  (python#140261)

Fix memory leak in sub-interpreter creation caused by overwriting of the previously used `_malloced` field. Now the pointer is stored in the first word of the memory block to avoid it being overwritten accidentally. 

Co-authored-by: Kumar Aditya <[email protected]>

Reviewers

ZeroIntensity

ZeroIntensity approved these changes

kumaraditya303

kumaraditya303 approved these changes

ericsnowcurrently

Awaiting requested review from ericsnowcurrently

ericsnowcurrently is a code owner

Uh oh!

There was an error while loading. Please reload this page.

Assignees

kumaraditya303

Labels

interpreter-core

(Objects, Python, Grammar, and Parser dirs)

topic-subinterpreters

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

Memory leak in test_sys with subinterpreters creation (AddressSanitizer detection)

Uh oh!

There was an error while loading. Please reload this page.

3 participants

Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.

You are visitor 01402503 — GeezerVison does not store the pages you look up.
Best viewed with Netscape Navigator 4.7 or Internet Explorer 6 at 800×600. No cookies required.

GeezerVison

Conversation

ashm-dev commented Oct 14, 2025 • edited by bedevere-app Bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

kumaraditya303 commented Oct 14, 2025

Uh oh!

Uh oh!

Uh oh!

bedevere-app Bot commented Oct 14, 2025

Uh oh!

bedevere-app Bot commented Oct 14, 2025

Uh oh!

ZeroIntensity commented Oct 15, 2025

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

ashm-dev commented Oct 14, 2025 •

edited by bedevere-app Bot

Loading

Uh oh!

There was an error while loading. Please reload this page.