Vulnerability-Lookup

GHSA-H262-73J6-24H2

Vulnerability from github – Published: 2026-05-08 15:31 – Updated: 2026-05-11 09:30

Details

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

sched_ext: Remove redundant css_put() in scx_cgroup_init()

The iterator css_for_each_descendant_pre() walks the cgroup hierarchy under cgroup_lock(). It does not increment the reference counts on yielded css structs.

According to the cgroup documentation, css_put() should only be used to release a reference obtained via css_get() or css_tryget_online(). Since the iterator does not use either of these to acquire a reference, calling css_put() in the error path of scx_cgroup_init() causes a refcount underflow.

Remove the unbalanced css_put() to prevent a potential Use-After-Free (UAF) vulnerability.

Severity ?

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-43438"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-08T15:16:56Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Remove redundant css_put() in scx_cgroup_init()\n\nThe iterator css_for_each_descendant_pre() walks the cgroup hierarchy\nunder cgroup_lock(). It does not increment the reference counts on\nyielded css structs.\n\nAccording to the cgroup documentation, css_put() should only be used\nto release a reference obtained via css_get() or css_tryget_online().\nSince the iterator does not use either of these to acquire a reference,\ncalling css_put() in the error path of scx_cgroup_init() causes a\nrefcount underflow.\n\nRemove the unbalanced css_put() to prevent a potential Use-After-Free\n(UAF) vulnerability.",
  "id": "GHSA-h262-73j6-24h2",
  "modified": "2026-05-11T09:30:31Z",
  "published": "2026-05-08T15:31:28Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43438"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1336b579f6079fb8520be03624fcd9ba443c930b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6eaaa67d6998f6c30c462b140db8c062e07ec473"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bf50f3285eda8a0173625fcdb5f183f96e1008cd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cc095cd305fddbe25a968e4a78436ff9476cf0f6"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-43438 (GCVE-0-2026-43438)

Vulnerability from cvelistv5 – Published: 2026-05-08 14:22 – Updated: 2026-05-11 22:24

Title

sched_ext: Remove redundant css_put() in scx_cgroup_init()

Summary

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Remove redundant css_put() in scx_cgroup_init() The iterator css_for_each_descendant_pre() walks the cgroup hierarchy under cgroup_lock(). It does not increment the reference counts on yielded css structs. According to the cgroup documentation, css_put() should only be used to release a reference obtained via css_get() or css_tryget_online(). Since the iterator does not use either of these to acquire a reference, calling css_put() in the error path of scx_cgroup_init() causes a refcount underflow. Remove the unbalanced css_put() to prevent a potential Use-After-Free (UAF) vulnerability.

Severity ?

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux

References

4 references

URL	Tags
https://git.kernel.org/stable/c/cc095cd305fddbe25…
https://git.kernel.org/stable/c/6eaaa67d6998f6c30…
https://git.kernel.org/stable/c/bf50f3285eda8a017…
https://git.kernel.org/stable/c/1336b579f6079fb85…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 8195136669661fdfe54e9a8923c33b31c92fc1da , < cc095cd305fddbe25a968e4a78436ff9476cf0f6 (git) Affected: 8195136669661fdfe54e9a8923c33b31c92fc1da , < 6eaaa67d6998f6c30c462b140db8c062e07ec473 (git) Affected: 8195136669661fdfe54e9a8923c33b31c92fc1da , < bf50f3285eda8a0173625fcdb5f183f96e1008cd (git) Affected: 8195136669661fdfe54e9a8923c33b31c92fc1da , < 1336b579f6079fb8520be03624fcd9ba443c930b (git)
Linux	Linux	Affected: 6.12 Unaffected: 0 , < 6.12 (semver) Unaffected: 6.12.78 , ≤ 6.12.* (semver) Unaffected: 6.18.19 , ≤ 6.18.* (semver) Unaffected: 6.19.9 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

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JSON

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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-H262-73J6-24H2

CVE-2026-43438 (GCVE-0-2026-43438)

Tags

Sightings

Nomenclature