CVE-2024-26727

Kernel crash via subvolume root-read race

Published Apr 3, 2024 · Updated May 23, 2026

Reachable assertion in Linux btrfs allows local users to crash the kernel during concurrent subvolume-creation operations. A back-reference walk can load the new subvolume root and assign its anonymous device number before btrfs_get_new_fs_root consumes a separately preallocated number, causing the !anon_dev assertion in fs/btrfs/disk-io.c to fail. A local user must be able to create a btrfs subvolume and win the concurrent root-read race; success interrupts the entire host rather than only the invoking process.

CVSS severity5.5
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reachable assertion in Linux btrfs allows local users to crash the kernel during concurrent subvolume-creation operations. A back-reference walk can load the new subvolume root and assign its anonymous device number before btrfs_get_new_fs_root consumes a separately preallocated number, causing the !anon_dev assertion in fs/btrfs/disk-io.c to fail. A local user must be able to create a btrfs subvolume and win the concurrent root-read race; success interrupts the entire host rather than only the invoking process.

The record

CVE
CVE-2024-26727
Published
Apr 3, 2024
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-617, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 3, 2024CVE publishedPublication date reported by the CVE source.
  2. May 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 <3f5d47eb163bceb1b9e613c9003bae5fefc0046f
  2. Affected versionversion=2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 <5a172344bfdabb46458e03708735d7b1a918c468
  3. Affected versionversion=2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 <66b317a2fc45b2ef66527ee3f8fa08fb5beab88d
  4. Affected versionversion=2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 <833775656d447c545133a744a0ed1e189ce61430
  5. Affected versionversion=2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 <e03ee2fe873eb68c1f9ba5112fee70303ebf9dfb
  6. Affected versionversion=2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 <e31546b0f34af21738c4ceac47d662c00ee6382f
  7. Affected versionversion=5.8.3 <5.9
  8. Affected versionversion=5.9
  9. Affected versionversion=917d608fe375041eb7f29befa6a6d7fd3cf32dde

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 <3f5d47eb163bceb1b9e613c9003bae5fefc0046f; version=2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 <5a172344bfdabb46458e03708735d7b1a918c468; version=2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 <66b317a2fc45b2ef66527ee3f8fa08fb5beab88d; version=2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 <833775656d447c545133a744a0ed1e189ce61430; version=2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 <e03ee2fe873eb68c1f9ba5112fee70303ebf9dfb; version=2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 <e31546b0f34af21738c4ceac47d662c00ee6382f; version=5.8.3 <5.9; version=5.9; version=917d608fe375041eb7f29befa6a6d7fd3cf32dde

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-617Reachable Assertion
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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