---
id: CVE-2023-53867
title: 'ceph: fix potential use-after-free bug when trimming caps'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ceph: fix potential use-after-free bug when trimming caps

  When trimming the caps and just after the 'session->s_cap_lock' is
  released in ceph_iterate_session_caps() th…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 2f2dc053404febedc9c273452d9d518fb31fde72 <
    2b2515b8095cf2149bef44383a99d5b5677f1831
  - >-
    Linux >= 2f2dc053404febedc9c273452d9d518fb31fde72 <
    448875a73e16ba7d81dec9274ce9d33a12d092fb
  - >-
    Linux >= 2f2dc053404febedc9c273452d9d518fb31fde72 <
    ae6e935618d99cdba11eab4714092e7e5f13cf7e
  - >-
    Linux >= 2f2dc053404febedc9c273452d9d518fb31fde72 <
    aaf67de78807c59c35bafb5003d4fb457c764800
  - Linux 2.6.34
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-10-15T21:37:43.826196Z'
published: '2025-12-24'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T21:41:37.567Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2023-53867'
references:
  - url: 'https://git.kernel.org/stable/c/2b2515b8095cf2149bef44383a99d5b5677f1831'
  - url: 'https://git.kernel.org/stable/c/448875a73e16ba7d81dec9274ce9d33a12d092fb'
  - url: 'https://git.kernel.org/stable/c/ae6e935618d99cdba11eab4714092e7e5f13cf7e'
  - url: 'https://git.kernel.org/stable/c/aaf67de78807c59c35bafb5003d4fb457c764800'
tags:
  - cve.org
epss: 0.00532
epssPercentile: 0.43609
ingestedAt: '2026-10-15T22:48:25.422Z'
---

## Overview

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

ceph: fix potential use-after-free bug when trimming caps

When trimming the caps and just after the 'session->s_cap_lock' is
released in ceph_iterate_session_caps() the cap maybe removed by
another thread, and when using the stale cap memory in the callbacks
it will trigger use-after-free crash.

We need to check the existence of the cap just after the 'ci->i_ceph_lock'
being acquired. And do nothing if it's already removed.

## Affected

- `Linux >= 2f2dc053404febedc9c273452d9d518fb31fde72 < 2b2515b8095cf2149bef44383a99d5b5677f1831`
- `Linux >= 2f2dc053404febedc9c273452d9d518fb31fde72 < 448875a73e16ba7d81dec9274ce9d33a12d092fb`
- `Linux >= 2f2dc053404febedc9c273452d9d518fb31fde72 < ae6e935618d99cdba11eab4714092e7e5f13cf7e`
- `Linux >= 2f2dc053404febedc9c273452d9d518fb31fde72 < aaf67de78807c59c35bafb5003d4fb457c764800`
- `Linux 2.6.34`

## Remediation

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