---
id: CVE-2026-89652
title: 'ceph: bound copied dentry name length in NFS export get_name'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ceph: bound copied dentry name length in NFS export get_name

  ceph_get_name() copies the MDS-supplied name into the caller's
  NAME_MAX-sized buffer with memcpy(name, rin…
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
cwe:
  - CWE-120
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 19913b4eac4a230dccb548931358398f45dabe4c <
    a294064e0e0f81ea607b2f019e16888aa1b0a011
  - >-
    Linux >= 19913b4eac4a230dccb548931358398f45dabe4c <
    61d9f27b191b838b96b697ce0bfaee39a138243a
  - >-
    Linux >= 19913b4eac4a230dccb548931358398f45dabe4c <
    06fb5e623cdc2402d6bb29be94d9beb9a826ffec
  - >-
    Linux >= 19913b4eac4a230dccb548931358398f45dabe4c <
    e7c2fd3893a7f7fcd7e8cf0b2c6348bb1e893df6
  - >-
    Linux >= 19913b4eac4a230dccb548931358398f45dabe4c <
    eff8013c5a8916613c742ae5a2cc341cb605c0ae
  - Linux 3.15
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-10-16T19:25:18.510719Z'
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:50:23.873Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89652'
references:
  - url: 'https://git.kernel.org/stable/c/a294064e0e0f81ea607b2f019e16888aa1b0a011'
  - url: 'https://git.kernel.org/stable/c/61d9f27b191b838b96b697ce0bfaee39a138243a'
  - url: 'https://git.kernel.org/stable/c/06fb5e623cdc2402d6bb29be94d9beb9a826ffec'
  - url: 'https://git.kernel.org/stable/c/e7c2fd3893a7f7fcd7e8cf0b2c6348bb1e893df6'
  - url: 'https://git.kernel.org/stable/c/eff8013c5a8916613c742ae5a2cc341cb605c0ae'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89652.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89652'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532101'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89652'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89652'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89652.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.00457
epssPercentile: 0.39484
scores:
  cna: 9.8
  vendor: 7
ingestedAt: '2026-09-14T15:23:07.450Z'
---

## Overview

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

ceph: bound copied dentry name length in NFS export get_name

ceph_get_name() copies the MDS-supplied name into the caller's
NAME_MAX-sized buffer with memcpy(name, rinfo->dname, rinfo->dname_len)
and then writes name[rinfo->dname_len] = 0, without checking dname_len
against NAME_MAX. A malicious or buggy MDS that returns a LOOKUPNAME reply
with dname_len > NAME_MAX overflows the buffer. __get_snap_name() copies
rde->name / rde->name_len the same unchecked way.

Impact: a malicious or compromised Ceph MDS overflows the NAME_MAX name
buffer in a client's NFS-export get_name path, a slab out-of-bounds write
reported by KASAN. Reachable when a CephFS mount is re-exported over NFS.

Add ceph_export_copy_name(), which rejects lengths above NAME_MAX with
-ENAMETOOLONG before the copy, and use it in both ceph_get_name() and
__get_snap_name().

## Affected

- `Linux >= 19913b4eac4a230dccb548931358398f45dabe4c < a294064e0e0f81ea607b2f019e16888aa1b0a011`
- `Linux >= 19913b4eac4a230dccb548931358398f45dabe4c < 61d9f27b191b838b96b697ce0bfaee39a138243a`
- `Linux >= 19913b4eac4a230dccb548931358398f45dabe4c < 06fb5e623cdc2402d6bb29be94d9beb9a826ffec`
- `Linux >= 19913b4eac4a230dccb548931358398f45dabe4c < e7c2fd3893a7f7fcd7e8cf0b2c6348bb1e893df6`
- `Linux >= 19913b4eac4a230dccb548931358398f45dabe4c < eff8013c5a8916613c742ae5a2cc341cb605c0ae`
- `Linux 3.15`

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, … · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89652.json)