---
id: CVE-2026-68154
title: 'libceph: reject zero bucket types in crush_decode'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  libceph: reject zero bucket types in crush_decode

  CRUSH bucket type 0 is reserved for devices.  The mapper relies on
  that invariant and uses type 0 to identify leaf de…
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 >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 <
    952ca5dc99913d169263f59fd689f586729a13c1
  - >-
    Linux >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 <
    146461f09565afe3665e65b0423d3d6b0fe806c5
  - >-
    Linux >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 <
    80fc40e11cda1b5d990a3f69c6efa344fb5cd987
  - >-
    Linux >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 <
    b8a9fb6bf806f9c4891e71ae1beab0c07c23a877
  - >-
    Linux >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 <
    826cd1de5802fd392922785f9b64d76e65d2a100
  - >-
    Linux >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 <
    3b2f1937f5fce8b7dd5432e7693e3cc8b5eece56
  - >-
    Linux >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 <
    70998f91030ee083ecb336a1dff0701c20a38081
  - >-
    Linux >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 <
    05f90284223381005d6bcddab3fda4a97f9c3401
  - Linux 2.6.34
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-10-16T15:45:00.533524Z'
published: '2026-08-10'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:53:00.744Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-68154'
references:
  - url: 'https://git.kernel.org/stable/c/952ca5dc99913d169263f59fd689f586729a13c1'
  - url: 'https://git.kernel.org/stable/c/146461f09565afe3665e65b0423d3d6b0fe806c5'
  - url: 'https://git.kernel.org/stable/c/80fc40e11cda1b5d990a3f69c6efa344fb5cd987'
  - url: 'https://git.kernel.org/stable/c/b8a9fb6bf806f9c4891e71ae1beab0c07c23a877'
  - url: 'https://git.kernel.org/stable/c/826cd1de5802fd392922785f9b64d76e65d2a100'
  - url: 'https://git.kernel.org/stable/c/3b2f1937f5fce8b7dd5432e7693e3cc8b5eece56'
  - url: 'https://git.kernel.org/stable/c/70998f91030ee083ecb336a1dff0701c20a38081'
  - url: 'https://git.kernel.org/stable/c/05f90284223381005d6bcddab3fda4a97f9c3401'
tags:
  - cve.org
epss: 0.00714
epssPercentile: 0.52732
ingestedAt: '2026-10-16T17:24:46.846Z'
---

## Overview

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

libceph: reject zero bucket types in crush_decode

CRUSH bucket type 0 is reserved for devices.  The mapper relies on
that invariant and uses type 0 to identify leaf devices.

If crush_decode() accepts a bucket with type 0, a malformed CRUSH map
can make the mapper treat a negative bucket ID as a device and pass it
to is_out(), which then indexes the OSD weight array with a negative
value.

Reject zero bucket types while decoding the CRUSH map so the invalid
state never reaches the mapper.

## Affected

- `Linux >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 < 952ca5dc99913d169263f59fd689f586729a13c1`
- `Linux >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 < 146461f09565afe3665e65b0423d3d6b0fe806c5`
- `Linux >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 < 80fc40e11cda1b5d990a3f69c6efa344fb5cd987`
- `Linux >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 < b8a9fb6bf806f9c4891e71ae1beab0c07c23a877`
- `Linux >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 < 826cd1de5802fd392922785f9b64d76e65d2a100`
- `Linux >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 < 3b2f1937f5fce8b7dd5432e7693e3cc8b5eece56`
- `Linux >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 < 70998f91030ee083ecb336a1dff0701c20a38081`
- `Linux >= f24e9980eb860d8600cbe5ef3d2fd9295320d229 < 05f90284223381005d6bcddab3fda4a97f9c3401`
- `Linux 2.6.34`

## Remediation

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