---
id: CVE-2026-52930
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ipc/shm: serialize orphan cleanup with shm_nattch updates

  shm_destroy_orphaned() walks the shm idr under shm_ids(ns).rwsem, but that
  does not serialize all fields test…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ipc/shm: serialize orphan cleanup with shm_nattch updates

  shm_destroy_orphaned() walks the shm idr under shm_ids(ns).rwsem, but that
  does not serialize all fields test…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 3.1, < 5.10.259'
  - 'linux_kernel >= 5.11, < 5.15.210'
  - 'linux_kernel >= 5.16, < 6.1.176'
  - 'linux_kernel >= 6.2, < 6.6.143'
  - 'linux_kernel >= 6.7, < 6.12.94'
  - 'linux_kernel >= 6.13, < 6.18.36'
  - 'linux_kernel >= 6.19, < 7.0.13'
  - linux_kernel = 7.1
patched:
  - linux_kernel 7.0.13
published: '2026-06-24'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T09:18:11.377'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-52930'
references:
  - url: 'https://git.kernel.org/stable/c/030bbc857bd51d4b25a90d931d3f8775ef22823a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1f0d01e35dbb228084d5187212e32c91a30dcbeb'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2e5c6f4fd4001562781e99bbfc7f1f0127187542'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6560be3f6a5bb84f006f184f0c966747bb58e1a3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/92cda2593cf2ed25b0e9d78e5e6d8303bba1a064'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b1e9aef48e4d8a0c1b54fb913077b0824ed7d650'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b5107b4ce3ad45fcf369ee2058c8910620f4b5a8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/db752ebfdaf2c7f27cd9690ef48b616af068319c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-019113.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00117
epssPercentile: 0.01497
ingestedAt: '2026-09-08T13:33:25.072Z'
---

## Overview

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

ipc/shm: serialize orphan cleanup with shm_nattch updates

shm_destroy_orphaned() walks the shm idr under shm_ids(ns).rwsem, but that
does not serialize all fields tested by shm_may_destroy().  In particular,
shm_nattch is updated while holding shm_perm.lock, and attach paths can do
that without holding the rwsem.

Do not decide that an orphaned segment is unused before taking the object
lock.  Move the shm_may_destroy() check under shm_perm.lock, matching the
other destroy paths, and unlock the segment when it no longer qualifies
for removal.

## Affected

- `linux_kernel >= 3.1, < 5.10.259`
- `linux_kernel >= 5.11, < 5.15.210`
- `linux_kernel >= 5.16, < 6.1.176`
- `linux_kernel >= 6.2, < 6.6.143`
- `linux_kernel >= 6.7, < 6.12.94`
- `linux_kernel >= 6.13, < 6.18.36`
- `linux_kernel >= 6.19, < 7.0.13`
- `linux_kernel = 7.1`

## Remediation

Upgrade past the affected range:

- `linux_kernel 7.0.13`