Vulnerability-Lookup

GHSA-PMW2-6GH9-J59G

Vulnerability from github – Published: 2026-05-27 15:33 – Updated: 2026-05-27 15:33

Details

In the Linux kernel, the following vulnerability has been resolved:

mm/mempolicy: fix memory leaks in weighted_interleave_auto_store()

weighted_interleave_auto_store() fetches old_wi_state inside the if (!input) block only. This causes two memory leaks:

When a user writes "false" and the current mode is already manual, the function returns early without freeing the freshly allocated new_wi_state.
When a user writes "true", old_wi_state stays NULL because the fetch is skipped entirely. The old state is then overwritten by rcu_assign_pointer() but never freed, since the cleanup path is gated on old_wi_state being non-NULL. A user can trigger this repeatedly by writing "1" in a loop.

Fix both leaks by moving the old_wi_state fetch before the input check, making it unconditional. This also allows a unified early return for both "true" and "false" when the requested mode matches the current mode.

Reviewed by: Donet Tom donettom@linux.ibm.com

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{
  "affected": [],
  "aliases": [
    "CVE-2026-46042"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-27T14:17:23Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/mempolicy: fix memory leaks in weighted_interleave_auto_store()\n\nweighted_interleave_auto_store() fetches old_wi_state inside the if\n(!input) block only.  This causes two memory leaks:\n\n1. When a user writes \"false\" and the current mode is already manual,\n   the function returns early without freeing the freshly allocated\n   new_wi_state.\n\n2. When a user writes \"true\", old_wi_state stays NULL because the\n   fetch is skipped entirely. The old state is then overwritten by\n   rcu_assign_pointer() but never freed, since the cleanup path is\n   gated on old_wi_state being non-NULL. A user can trigger this\n   repeatedly by writing \"1\" in a loop.\n\nFix both leaks by moving the old_wi_state fetch before the input check,\nmaking it unconditional.  This also allows a unified early return for both\n\"true\" and \"false\" when the requested mode matches the current mode.\n\nReviewed by: Donet Tom \u003cdonettom@linux.ibm.com\u003e",
  "id": "GHSA-pmw2-6gh9-j59g",
  "modified": "2026-05-27T15:33:22Z",
  "published": "2026-05-27T15:33:21Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46042"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/39caa9ca863f96b3d00447c5aa200cabda489856"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6fae274ce0e3109cbbc4c18b354eaace1f0af7d7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c42a7efb9060d89b72708ffaf255d0002c2164a7"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-46042 (GCVE-0-2026-46042)

Vulnerability from cvelistv5 – Published: 2026-05-27 12:56 – Updated: 2026-05-27 12:56

Title

mm/mempolicy: fix memory leaks in weighted_interleave_auto_store()

Summary

In the Linux kernel, the following vulnerability has been resolved: mm/mempolicy: fix memory leaks in weighted_interleave_auto_store() weighted_interleave_auto_store() fetches old_wi_state inside the if (!input) block only. This causes two memory leaks: 1. When a user writes "false" and the current mode is already manual, the function returns early without freeing the freshly allocated new_wi_state. 2. When a user writes "true", old_wi_state stays NULL because the fetch is skipped entirely. The old state is then overwritten by rcu_assign_pointer() but never freed, since the cleanup path is gated on old_wi_state being non-NULL. A user can trigger this repeatedly by writing "1" in a loop. Fix both leaks by moving the old_wi_state fetch before the input check, making it unconditional. This also allows a unified early return for both "true" and "false" when the requested mode matches the current mode. Reviewed by: Donet Tom <donettom@linux.ibm.com>

Severity

No CVSS data available.

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/c42a7efb9060d89b7…
https://git.kernel.org/stable/c/39caa9ca863f96b3d…
https://git.kernel.org/stable/c/6fae274ce0e3109cb…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: e341f9c3c8412e57fe0042a33a2640245ecdf619 , < c42a7efb9060d89b72708ffaf255d0002c2164a7 (git) Affected: e341f9c3c8412e57fe0042a33a2640245ecdf619 , < 39caa9ca863f96b3d00447c5aa200cabda489856 (git) Affected: e341f9c3c8412e57fe0042a33a2640245ecdf619 , < 6fae274ce0e3109cbbc4c18b354eaace1f0af7d7 (git)
Linux	Linux	Affected: 6.16 Unaffected: 0 , < 6.16 (semver) Unaffected: 6.18.27 , ≤ 6.18.* (semver) Unaffected: 7.0.4 , ≤ 7.0.* (semver) Unaffected: 7.1-rc1 , ≤ * (original_commit_for_fix)

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JSON

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      "affected": [
        {
          "defaultStatus": "unaffected",
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          "programFiles": [
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          "vendor": "Linux",
          "versions": [
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              "status": "affected",
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            },
            {
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      "cpeApplicability": [
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/mempolicy: fix memory leaks in weighted_interleave_auto_store()\n\nweighted_interleave_auto_store() fetches old_wi_state inside the if\n(!input) block only.  This causes two memory leaks:\n\n1. When a user writes \"false\" and the current mode is already manual,\n   the function returns early without freeing the freshly allocated\n   new_wi_state.\n\n2. When a user writes \"true\", old_wi_state stays NULL because the\n   fetch is skipped entirely. The old state is then overwritten by\n   rcu_assign_pointer() but never freed, since the cleanup path is\n   gated on old_wi_state being non-NULL. A user can trigger this\n   repeatedly by writing \"1\" in a loop.\n\nFix both leaks by moving the old_wi_state fetch before the input check,\nmaking it unconditional.  This also allows a unified early return for both\n\"true\" and \"false\" when the requested mode matches the current mode.\n\nReviewed by: Donet Tom \u003cdonettom@linux.ibm.com\u003e"
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    "datePublished": "2026-05-27T12:56:56.830Z",
    "dateReserved": "2026-05-13T15:03:33.094Z",
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-PMW2-6GH9-J59G

CVE-2026-46042 (GCVE-0-2026-46042)

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Nomenclature