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GHSA-MPX2-CMQF-859J

Vulnerability from github – Published: 2026-07-29 09:31 – Updated: 2026-07-30 06:32

Details

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

perf/core: Detach event groups during remove_on_exec

perf_event_remove_on_exec() removes events by calling perf_event_exit_event(). For top-level events, this removes the event from the context with DETACH_EXIT only.

This can leave inconsistent group state when a removed event is a group leader and the group contains siblings without remove_on_exec. If the group was active, the surviving siblings can remain active and attached to the removed leader's sibling list, but are no longer represented by a valid group leader on the PMU context active lists.

A later close of the removed leader uses DETACH_GROUP and can promote the still-active siblings from this stale group state. The next schedule-in can then add an already-linked active_list entry again, corrupting the PMU context active list.

With DEBUG_LIST enabled, this is caught as a list_add double-add in merge_sched_in().

Fix this by detaching group relationships when remove_on_exec removes an event. This preserves the existing task-exit and revoke behavior, while ensuring surviving siblings are ungrouped before the removed event leaves the context.

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-2026-64556"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-29T09:16:30Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/core: Detach event groups during remove_on_exec\n\nperf_event_remove_on_exec() removes events by calling\nperf_event_exit_event(). For top-level events, this removes the event from\nthe context with DETACH_EXIT only.\n\nThis can leave inconsistent group state when a removed event is a group\nleader and the group contains siblings without remove_on_exec. If the group\nwas active, the surviving siblings can remain active and attached to the\nremoved leader\u0027s sibling list, but are no longer represented by a valid\ngroup leader on the PMU context active lists.\n\nA later close of the removed leader uses DETACH_GROUP and can promote the\nstill-active siblings from this stale group state. The next schedule-in can\nthen add an already-linked active_list entry again, corrupting the PMU\ncontext active list.\n\nWith DEBUG_LIST enabled, this is caught as a list_add double-add in\nmerge_sched_in().\n\nFix this by detaching group relationships when remove_on_exec removes an\nevent. This preserves the existing task-exit and revoke behavior, while\nensuring surviving siblings are ungrouped before the removed event leaves\nthe context.",
  "id": "GHSA-mpx2-cmqf-859j",
  "modified": "2026-07-30T06:32:35Z",
  "published": "2026-07-29T09:31:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64556"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/037a3c43edfb597665dd34457cd22b14692f2ba3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/06ccef0434e98058ddae7bcebc901f93d22b7653"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/39358e856fb89e62e3c8d7389a2dc4ec33dbe90e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4cdb1b3ab96eb1b7eb70bc5c82fede334bd60df2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a2d5d3ee7b6e3953114726b1521e62123ab5b043"
    }
  ],
  "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-2026-64556 (GCVE-0-2026-64556)

Vulnerability from cvelistv5 – Published: 2026-07-29 08:01 – Updated: 2026-07-30 06:06

Title

perf/core: Detach event groups during remove_on_exec

Summary

In the Linux kernel, the following vulnerability has been resolved: perf/core: Detach event groups during remove_on_exec perf_event_remove_on_exec() removes events by calling perf_event_exit_event(). For top-level events, this removes the event from the context with DETACH_EXIT only. This can leave inconsistent group state when a removed event is a group leader and the group contains siblings without remove_on_exec. If the group was active, the surviving siblings can remain active and attached to the removed leader's sibling list, but are no longer represented by a valid group leader on the PMU context active lists. A later close of the removed leader uses DETACH_GROUP and can promote the still-active siblings from this stale group state. The next schedule-in can then add an already-linked active_list entry again, corrupting the PMU context active list. With DEBUG_LIST enabled, this is caught as a list_add double-add in merge_sched_in(). Fix this by detaching group relationships when remove_on_exec removes an event. This preserves the existing task-exit and revoke behavior, while ensuring surviving siblings are ungrouped before the removed event leaves the context.

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

5 references

URL	Tags
https://git.kernel.org/stable/c/4cdb1b3ab96eb1b7e…
https://git.kernel.org/stable/c/39358e856fb89e62e…
https://git.kernel.org/stable/c/a2d5d3ee7b6e39531…
https://git.kernel.org/stable/c/06ccef0434e98058d…
https://git.kernel.org/stable/c/037a3c43edfb59766…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 2e498d0a74e5b88a6689ae1b811f247f91ff188e , < 4cdb1b3ab96eb1b7eb70bc5c82fede334bd60df2 (git) Affected: 2e498d0a74e5b88a6689ae1b811f247f91ff188e , < 39358e856fb89e62e3c8d7389a2dc4ec33dbe90e (git) Affected: 2e498d0a74e5b88a6689ae1b811f247f91ff188e , < a2d5d3ee7b6e3953114726b1521e62123ab5b043 (git) Affected: 2e498d0a74e5b88a6689ae1b811f247f91ff188e , < 06ccef0434e98058ddae7bcebc901f93d22b7653 (git) Affected: 2e498d0a74e5b88a6689ae1b811f247f91ff188e , < 037a3c43edfb597665dd34457cd22b14692f2ba3 (git)
Linux	Linux	Affected: 5.13 Unaffected: 0 , < 5.13 (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.96 , ≤ 6.12.* (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2-rc2 , ≤ * (original_commit_for_fix)

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        {
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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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

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GHSA-MPX2-CMQF-859J

CVE-2026-64556 (GCVE-0-2026-64556)

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Nomenclature