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BUG: fix memory leak in np.zeros when fill-zero loop raises#31320

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seberg merged 2 commits into
numpy:mainfrom
MaartenBaert:main
Apr 27, 2026
Merged

BUG: fix memory leak in np.zeros when fill-zero loop raises#31320
seberg merged 2 commits into
numpy:mainfrom
MaartenBaert:main

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PR summary

This PR fixes a memory leak in np.zeros that occurs when the fill-zero loop raises an exception (which can happen for custom user-defined dtypes). It does this by setting NPY_ARRAY_OWNDATA earlier to ensure the data will be deallocated, combined with changes to mem_handler cleanup to avoid a double-decref.

I'm not entirely sure whether this is the most appropriate way to fix the leak, but it does seem to work correctly based on testing with tracemalloc.

AI Disclosure

The bug was detected through testing with tracemalloc, then located and fixed by Claude Opus 4.7.
Full AI-generated description: https://gist.github.com/MaartenBaert/f3eadd280f84ef6896586025f59788ec

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Thanks a lot, looks good to me! (Will hold off merging a moment.)

I guess adding a test that fails during the zero filling is annoying, but your DType tested this (maybe accidentally, so?).
(Our CI now has leak sanitizer running even, but we have no dtype that can be made to fail unless we write one just for this...)

Comment thread numpy/_core/src/multiarray/arrayobject.c

fail:
NPY_traverse_info_xfree(&fill_zero_info);
Py_XDECREF(fa->mem_handler);

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Hah, "fun" that the old logic worked out here because the owndata flag wasn't set yet and mem_handler was never deallocated.

@charris charris added 00 - Bug 09 - Backport-Candidate PRs tagged should be backported labels Apr 25, 2026
@seberg

seberg commented Apr 27, 2026

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OK, let's put this in, thanks again.

@seberg seberg merged commit bab58ec into numpy:main Apr 27, 2026
95 of 97 checks passed
@charris charris removed the 09 - Backport-Candidate PRs tagged should be backported label Apr 28, 2026
charris pushed a commit that referenced this pull request Apr 28, 2026
BUG: fix memory leak in np.zeros when fill-zero loop raises
charris added a commit that referenced this pull request Apr 28, 2026
BUG: fix memory leak in np.zeros when fill-zero loop raises (#31320)
MaanasArora pushed a commit to MaanasArora/numpy that referenced this pull request May 7, 2026
BUG: fix memory leak in np.zeros when fill-zero loop raises
736-c41-2c1-e464fc974 added a commit to Swiss-Armed-Forces/Loom that referenced this pull request Jun 29, 2026
This MR contains the following updates:

| Package | Type | Update | Change | OpenSSF |
|---|---|---|---|---|
| [debugpy](https://aka.ms/debugpy) ([source](https://github.com/microsoft/debugpy)) | dev | patch | `1.8.20` → `1.8.21` | [![OpenSSF Scorecard](https://api.securityscorecards.dev/projects/github.com/microsoft/debugpy/badge)](https://securityscorecards.dev/viewer/?uri=github.com/microsoft/debugpy) |
| [numpy](https://github.com/numpy/numpy) ([changelog](https://numpy.org/doc/stable/release)) | dependencies | patch | `2.4.4` → `2.4.6` | [![OpenSSF Scorecard](https://api.securityscorecards.dev/projects/github.com/numpy/numpy/badge)](https://securityscorecards.dev/viewer/?uri=github.com/numpy/numpy) |
| [pydantic-settings](https://github.com/pydantic/pydantic-settings) ([changelog](https://github.com/pydantic/pydantic-settings/releases)) | dependencies | patch | `2.14.0` → `2.14.2` | [![OpenSSF Scorecard](https://api.securityscorecards.dev/projects/github.com/pydantic/pydantic-settings/badge)](https://securityscorecards.dev/viewer/?uri=github.com/pydantic/pydantic-settings) |
| [python-multipart](https://github.com/Kludex/python-multipart) ([changelog](https://github.com/Kludex/python-multipart/blob/master/CHANGELOG.md)) | dependencies | patch | `^0.0.22` → `^0.0.32` | [![OpenSSF Scorecard](https://api.securityscorecards.dev/projects/github.com/Kludex/python-multipart/badge)](https://securityscorecards.dev/viewer/?uri=github.com/Kludex/python-multipart) |
| [types-requests](https://github.com/python/typeshed) ([changelog](https://github.com/typeshed-internal/stub_uploader/blob/main/data/changelogs/requests.md)) | dependencies | patch | `2.32.0.20240523` → `2.32.4.20260324` | [![OpenSSF Scorecard](https://api.securityscorecards.dev/projects/github.com/python/typeshed/badge)](https://securityscorecards.dev/viewer/?uri=github.com/python/typeshed) |

---

### Release Notes

<details>
<summary>microsoft/debugpy (debugpy)</summary>

### [`v1.8.21`](https://github.com/microsoft/debugpy/releases/tag/v1.8.21): debugpy v1.8.21

[Compare Source](microsoft/debugpy@v1.8.20...v1.8.21)

Fixes for:

- Return evaluate result in DAP response body instead of writing to stdout: [#&#8203;2027](microsoft/debugpy#2027)
- Prevent invalid `scopes` request from crashing debug session: [#&#8203;2026](microsoft/debugpy#2026)
- Skip uninitialized `__slots__` in variable resolver: [#&#8203;2024](microsoft/debugpy#2024)
- Handle `-c` arguments that are `bytes` instead of `str`: [#&#8203;2021](microsoft/debugpy#2021)
- Fix evaluation of variables from chained exception frames: [#&#8203;2018](microsoft/debugpy#2018)
- `ContinueRequest` with a specific `threadId` no longer resumes all threads (in-process adapter): [#&#8203;2012](microsoft/debugpy#2012)
- Avoid strong reference to exceptions during unwind: [#&#8203;2008](microsoft/debugpy#2008)
- Show error message on evaluate failures in the hover context: [#&#8203;2006](microsoft/debugpy#2006)
- Display `dlerror` output when `dlopen` fails: [#&#8203;2000](microsoft/debugpy#2000)
- Replace removed `pkgutil.get_loader` with `importlib.util.find_spec` in `get_fullname`: [#&#8203;1998](microsoft/debugpy#1998)

Enhancements:

- Add option to ignore all system exit codes: [#&#8203;2017](microsoft/debugpy#2017)
- Pull changes from pydevd up to March 2026: [#&#8203;2010](microsoft/debugpy#2010)

Infrastructure work:

- Suppress Flawfinder false positives on Cython memcpy / read-loop iterators (TSA [#&#8203;2816216](https://github.com/microsoft/debugpy/issues/2816216), [#&#8203;2816217](https://github.com/microsoft/debugpy/issues/2816217), [#&#8203;2816218](https://github.com/microsoft/debugpy/issues/2816218), [#&#8203;2816219](https://github.com/microsoft/debugpy/issues/2816219), [#&#8203;2816220](https://github.com/microsoft/debugpy/issues/2816220)): [#&#8203;2028](microsoft/debugpy#2028), [#&#8203;2029](microsoft/debugpy#2029), [#&#8203;2030](microsoft/debugpy#2030), [#&#8203;2031](microsoft/debugpy#2031), [#&#8203;2032](microsoft/debugpy#2032)

Thanks to [@&#8203;maxbachmann](https://github.com/maxbachmann), [@&#8203;mfussenegger](https://github.com/mfussenegger), and [@&#8203;sambrightman](https://github.com/sambrightman) for the commits.

</details>

<details>
<summary>numpy/numpy (numpy)</summary>

### [`v2.4.6`](https://github.com/numpy/numpy/releases/tag/v2.4.6): (May 18, 2026)

[Compare Source](numpy/numpy@v2.4.5...v2.4.6)

### NumPy 2.4.6 Release Notes

NumPy 2.4.6 is a quick release that fixes a regression discovered in the 2.4.5
release.

This release supports Python versions 3.11-3.14

#### Contributors

A total of 4 people contributed to this release. People with a "+" by their
names contributed a patch for the first time.

- !EarlMilktea
- Charles Harris
- Sebastian Berg
- Warren Weckesser

#### Pull requests merged

A total of 4 pull requests were merged for this release.

- [#&#8203;31444](numpy/numpy#31444): MAINT: Prepare 2.4.x for further development
- [#&#8203;31453](numpy/numpy#31453): BUG: Fix regression in `arr.conj()`
- [#&#8203;31459](numpy/numpy#31459): BUG: `np.linalg.svd(..., hermitian=True)` returns non-unitary...
- [#&#8203;31460](numpy/numpy#31460): BUG: Don't call INCREF/DECREF on descr in NpyStringAcquireAllocator...

### [`v2.4.5`](https://github.com/numpy/numpy/releases/tag/v2.4.5): (May 15, 2026)

[Compare Source](numpy/numpy@v2.4.4...v2.4.5)

### NumPy 2.4.5 Release Notes

NumPy 2.4.5 is a patch release that fixes bugs discovered after the 2.4.4
release, has some typing improvements, and maintains infrastructure.

This release supports Python versions 3.11-3.14

#### Contributors

A total of 17 people contributed to this release. People with a "+" by their
names contributed a patch for the first time.

- Aleksei Nikiforov
- Anarion Zuo +
- Ankit Ahlawat
- Breno Favaretto +
- Charles Harris
- Igor Krivenko +
- Ijtihed Kilani +
- Joren Hammudoglu
- Maarten Baert +
- Matti Picus
- Nathan Goldbaum
- Praneeth Kodumagulla +
- Ralf Gommers
- RoomWithOutRoof +
- Sebastian Berg
- Warren Weckesser
- div +

#### Pull requests merged

A total of 28 pull requests were merged for this release.

- [#&#8203;31093](numpy/numpy#31093): MAINT: Prepare 2.4.x for further development
- [#&#8203;31182](numpy/numpy#31182): TYP: fix `np.shape` assignability issue for python lists ([#&#8203;31171](numpy/numpy#31171))
- [#&#8203;31197](numpy/numpy#31197): ENH: Return rank 0 for empty matrices in matrix\_rank ([#&#8203;30422](numpy/numpy#30422))
- [#&#8203;31198](numpy/numpy#31198): CI/BUG: add native jobs for s390x, fix bug in `pack_inner`...
- [#&#8203;31199](numpy/numpy#31199): BUG: f2py map complex\_long\_double to NPY\_CLONGDOUBLE
- [#&#8203;31205](numpy/numpy#31205): MAINT: f2py: Stop setting re.\_MAXCACHE to 50.
- [#&#8203;31206](numpy/numpy#31206): BUG: fix heap buffer overflow in timedelta to string casts
- [#&#8203;31207](numpy/numpy#31207): MAINT: Rename ppc64le and s390x workflow ([#&#8203;31121](numpy/numpy#31121))
- [#&#8203;31208](numpy/numpy#31208): BUG: Fix matvec/vecmat in-place aliasing (out=input produces...
- [#&#8203;31209](numpy/numpy#31209): TYP: `tile`: accept numpy scalars and arrays as second argument...
- [#&#8203;31211](numpy/numpy#31211): DEP: Undo deprecation for np.dtype() signature used by old pickles...
- [#&#8203;31212](numpy/numpy#31212): REV: Manual revert of float16 svml use ([#&#8203;31178](numpy/numpy#31178))
- [#&#8203;31222](numpy/numpy#31222): TYP: `ix_` fix for boolean and non-1d input ([#&#8203;31218](numpy/numpy#31218))
- [#&#8203;31329](numpy/numpy#31329): BUG: incorrect temp elision for new-style (NEP 43) user-defined...
- [#&#8203;31330](numpy/numpy#31330): TYP: fix sliding\_window\_view axis parameter typing
- [#&#8203;31335](numpy/numpy#31335): BUG: Prevent deadlock due to downstream importing NumPy in dlopen...
- [#&#8203;31336](numpy/numpy#31336): BUG: Fix segfault in nditer.multi\_index when \_\_getitem\_\_ raises...
- [#&#8203;31338](numpy/numpy#31338): TYP: Fix ruff lint error
- [#&#8203;31357](numpy/numpy#31357): BUG: fix memory leak in np.zeros when fill-zero loop raises ([#&#8203;31320](numpy/numpy#31320))
- [#&#8203;31358](numpy/numpy#31358): BUG: np.einsum() fails with a 0-dimensional out argument and...
- [#&#8203;31379](numpy/numpy#31379): BUG: Fix signed overflow issue in npy\_gcd for INT\_MIN on s390x...
- [#&#8203;31383](numpy/numpy#31383): CI: remove Cirrus CI FreeBSD job ([#&#8203;31380](numpy/numpy#31380))
- [#&#8203;31390](numpy/numpy#31390): BUILD: newer MKL uses so.3
- [#&#8203;31391](numpy/numpy#31391): BLD/MAINT: improve support for Intel LLVM compilers
- [#&#8203;31401](numpy/numpy#31401): BUG: Avoid UB in [safe]()\[add,sub,mul] helpers ([#&#8203;31396](numpy/numpy#31396))
- [#&#8203;31402](numpy/numpy#31402): BUG: exclude \_\_pycache\_\_ directories from wheels ([#&#8203;31397](numpy/numpy#31397))
- [#&#8203;31404](numpy/numpy#31404): TYP: `_NestedSequence` type parameter default to work around...
- [#&#8203;31426](numpy/numpy#31426): TYP: Fix `DTypeLike` runtime type-checker support ([#&#8203;31425](numpy/numpy#31425))

</details>

<details>
<summary>pydantic/pydantic-settings (pydantic-settings)</summary>

### [`v2.14.2`](https://github.com/pydantic/pydantic-settings/releases/tag/v2.14.2)

[Compare Source](pydantic/pydantic-settings@v2.14.1...v2.14.2)

#### What's Changed

This is a security patch release.

- Prevent `NestedSecretsSettingsSource` from following symlinks outside `secrets_dir` by [@&#8203;hramezani](https://github.com/hramezani) in [#&#8203;889](pydantic/pydantic-settings#889)
- Prepare release 2.14.2 by [@&#8203;hramezani](https://github.com/hramezani) in [#&#8203;890](pydantic/pydantic-settings#890)

##### Security

Fixes [GHSA-4xgf-cpjx-pc3j](GHSA-4xgf-cpjx-pc3j): `NestedSecretsSettingsSource` with `secrets_nested_subdir=True` could follow a symbolic link inside `secrets_dir` pointing outside it, reading out-of-tree files into settings values and bypassing the `secrets_dir_max_size` cap. Affected versions: `>= 2.12.0, < 2.14.2`.

**Full Changelog**: <pydantic/pydantic-settings@v2.14.1...v2.14.2>

### [`v2.14.1`](https://github.com/pydantic/pydantic-settings/releases/tag/v2.14.1)

[Compare Source](pydantic/pydantic-settings@v2.14.0...v2.14.1)

#### What's Changed

- Bump the python-packages group with 4 updates by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;850](pydantic/pydantic-settings#850)
- Bump the python-packages group with 5 updates by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;854](pydantic/pydantic-settings#854)
- Bump the github-actions group with 3 updates by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;853](pydantic/pydantic-settings#853)
- Bump the python-packages group with 2 updates by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;856](pydantic/pydantic-settings#856)
- Fix field named `cls` conflicting with classmethod parameter by [@&#8203;hramezani](https://github.com/hramezani) in [#&#8203;858](pydantic/pydantic-settings#858)
- Prepare release 2.14.1 by [@&#8203;hramezani](https://github.com/hramezani) in [#&#8203;859](pydantic/pydantic-settings#859)

**Full Changelog**: <pydantic/pydantic-settings@v2.14.0...v2.14.1>

</details>

<details>
<summary>Kludex/python-multipart (python-multipart)</summary>

### [`v0.0.32`](https://github.com/Kludex/python-multipart/blob/HEAD/CHANGELOG.md#0032-2026-06-04)

[Compare Source](Kludex/python-multipart@0.0.31...0.0.32)

- Speed up partial-boundary scanning for CR/LF-dense part data [#&#8203;300](Kludex/python-multipart#300).

### [`v0.0.31`](https://github.com/Kludex/python-multipart/blob/HEAD/CHANGELOG.md#0031-2026-06-04)

[Compare Source](Kludex/python-multipart@0.0.30...0.0.31)

- Speed up multipart header parsing and callback dispatch [#&#8203;295](Kludex/python-multipart#295).
- Bound header field name size before validating [#&#8203;296](Kludex/python-multipart#296).
- Validate `Content-Length` is non-negative in `parse_form` [#&#8203;297](Kludex/python-multipart#297).

### [`v0.0.30`](https://github.com/Kludex/python-multipart/blob/HEAD/CHANGELOG.md#0030-2026-05-31)

[Compare Source](Kludex/python-multipart@0.0.29...0.0.30)

- Parse `application/x-www-form-urlencoded` bodies per the WHATWG URL standard, treating only `&` as a field separator [#&#8203;290](Kludex/python-multipart#290).
- Ignore RFC 2231/5987 extended parameters (`name*`, `filename*`) in `parse_options_header`, keeping the plain parameter authoritative per [RFC 7578 §4.2](https://datatracker.ietf.org/doc/html/rfc7578#section-4.2) [#&#8203;291](Kludex/python-multipart#291).

### [`v0.0.29`](https://github.com/Kludex/python-multipart/blob/HEAD/CHANGELOG.md#0029-2026-05-17)

[Compare Source](Kludex/python-multipart@0.0.28...0.0.29)

- Handle malformed RFC 2231 continuations in `parse_options_header` [#&#8203;270](Kludex/python-multipart#270).

### [`v0.0.28`](https://github.com/Kludex/python-multipart/blob/HEAD/CHANGELOG.md#0028-2026-05-10)

[Compare Source](Kludex/python-multipart@0.0.27...0.0.28)

- Speed up partial-boundary tail scan via `bytes.find` [#&#8203;281](Kludex/python-multipart#281).
- Cap multipart boundary length at 256 bytes [#&#8203;282](Kludex/python-multipart#282).

### [`v0.0.27`](https://github.com/Kludex/python-multipart/blob/HEAD/CHANGELOG.md#0027-2026-04-27)

[Compare Source](Kludex/python-multipart@0.0.26...0.0.27)

- Add multipart header limits [#&#8203;267](Kludex/python-multipart#267).
- Pass parse offsets via constructors [#&#8203;268](Kludex/python-multipart#268).

### [`v0.0.26`](https://github.com/Kludex/python-multipart/blob/HEAD/CHANGELOG.md#0026-2026-04-10)

[Compare Source](Kludex/python-multipart@0.0.25...0.0.26)

- Skip preamble before the first multipart boundary more efficiently [#&#8203;262](Kludex/python-multipart#262).
- Silently discard epilogue data after the closing multipart boundary [#&#8203;259](Kludex/python-multipart#259).

### [`v0.0.25`](https://github.com/Kludex/python-multipart/blob/HEAD/CHANGELOG.md#0025-2026-04-10)

[Compare Source](Kludex/python-multipart@0.0.24...0.0.25)

- Add MIME content type info to `File` [#&#8203;143](Kludex/python-multipart#143).
- Handle CTE values case-insensitively [#&#8203;258](Kludex/python-multipart#258).
- Remove custom `FormParser` classes [#&#8203;257](Kludex/python-multipart#257).
- Add `UPLOAD_DELETE_TMP` to `FormParser` config [#&#8203;254](Kludex/python-multipart#254).
- Emit `field_end` for trailing bare field names on finalize [#&#8203;230](Kludex/python-multipart#230).
- Handle multipart headers case-insensitively [#&#8203;252](Kludex/python-multipart#252).
- Apply Apache-2.0 properly [#&#8203;247](Kludex/python-multipart#247).

### [`v0.0.24`](https://github.com/Kludex/python-multipart/blob/HEAD/CHANGELOG.md#0024-2026-04-05)

[Compare Source](Kludex/python-multipart@0.0.23...0.0.24)

- Validate `chunk_size` in `parse_form()` [#&#8203;244](Kludex/python-multipart#244).

### [`v0.0.23`](https://github.com/Kludex/python-multipart/blob/HEAD/CHANGELOG.md#0023-2026-04-05)

[Compare Source](Kludex/python-multipart@0.0.22...0.0.23)

- Remove unused `trust_x_headers` parameter and `X-File-Name` fallback [#&#8203;196](Kludex/python-multipart#196).
- Return processed length from `QuerystringParser._internal_write` [#&#8203;229](Kludex/python-multipart#229).
- Cleanup metadata dunders from `__init__.py` [#&#8203;227](Kludex/python-multipart#227).

</details>

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this MR, check this box

---

This MR has been generated by [Mend Renovate](https://github.com/renovatebot/renovate).
<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0My4xMTAuMTYiLCJ1cGRhdGVkSW5WZXIiOiI0My4yNDYuMSIsInRhcmdldEJyYW5jaCI6Im1haW4iLCJsYWJlbHMiOlsiZGVwZW5kZW5jaWVzIiwicmVub3ZhdGUiXX0=-->

See merge request swiss-armed-forces/cyber-command/cea/loom!460

Co-authored-by: Loom MR Pipeline Trigger <group_103951964_bot_9504bb8dead6d4e406ad817a607f24be@noreply.gitlab.com>
Co-authored-by: shrewd-laidback palace <shrewd-laidback-palace-736-c41-2c1-e464fc974@swiss-armed-forces-open-source.ch>
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