---
id: CVE-2026-64556
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 …
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 2e498d0a74e5b88a6689ae1b811f247f91ff188e <
    4cdb1b3ab96eb1b7eb70bc5c82fede334bd60df2
  - >-
    Linux >= 2e498d0a74e5b88a6689ae1b811f247f91ff188e <
    39358e856fb89e62e3c8d7389a2dc4ec33dbe90e
  - >-
    Linux >= 2e498d0a74e5b88a6689ae1b811f247f91ff188e <
    a2d5d3ee7b6e3953114726b1521e62123ab5b043
  - >-
    Linux >= 2e498d0a74e5b88a6689ae1b811f247f91ff188e <
    06ccef0434e98058ddae7bcebc901f93d22b7653
  - >-
    Linux >= 2e498d0a74e5b88a6689ae1b811f247f91ff188e <
    037a3c43edfb597665dd34457cd22b14692f2ba3
  - Linux 5.13
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:42:33.956439Z'
published: '2026-07-29'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:52:52.422Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-64556'
references:
  - url: 'https://git.kernel.org/stable/c/4cdb1b3ab96eb1b7eb70bc5c82fede334bd60df2'
  - url: 'https://git.kernel.org/stable/c/39358e856fb89e62e3c8d7389a2dc4ec33dbe90e'
  - url: 'https://git.kernel.org/stable/c/a2d5d3ee7b6e3953114726b1521e62123ab5b043'
  - url: 'https://git.kernel.org/stable/c/06ccef0434e98058ddae7bcebc901f93d22b7653'
  - url: 'https://git.kernel.org/stable/c/037a3c43edfb597665dd34457cd22b14692f2ba3'
tags:
  - cve.org
epss: 0.00124
epssPercentile: 0.01942
ingestedAt: '2026-10-16T17:24:46.834Z'
---

## Overview

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.

## Affected

- `Linux >= 2e498d0a74e5b88a6689ae1b811f247f91ff188e < 4cdb1b3ab96eb1b7eb70bc5c82fede334bd60df2`
- `Linux >= 2e498d0a74e5b88a6689ae1b811f247f91ff188e < 39358e856fb89e62e3c8d7389a2dc4ec33dbe90e`
- `Linux >= 2e498d0a74e5b88a6689ae1b811f247f91ff188e < a2d5d3ee7b6e3953114726b1521e62123ab5b043`
- `Linux >= 2e498d0a74e5b88a6689ae1b811f247f91ff188e < 06ccef0434e98058ddae7bcebc901f93d22b7653`
- `Linux >= 2e498d0a74e5b88a6689ae1b811f247f91ff188e < 037a3c43edfb597665dd34457cd22b14692f2ba3`
- `Linux 5.13`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.