CVE-2024-40943

Filesystem corruption via concurrent hole punching

Published Jul 12, 2024 · Updated Aug 5, 2026

Race condition in Linux kernel OCFS2 allows local users to corrupt a mounted filesystem through concurrent direct I/O and hole punching. ocfs2_fallocate can remove an unwritten extent while ocfs2_dio_end_io_write later searches for and marks that same extent as written. Triggering the race requires local access to an already-mounted OCFS2 volume and can force the filesystem read-only, interrupting writes until offline repair.

CVSS severity7.8
High
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in Linux kernel OCFS2 allows local users to corrupt a mounted filesystem through concurrent direct I/O and hole punching. ocfs2_fallocate can remove an unwritten extent while ocfs2_dio_end_io_write later searches for and marks that same extent as written. Triggering the race requires local access to an already-mounted OCFS2 volume and can force the filesystem read-only, interrupting writes until offline repair.

The record

CVE
CVE-2024-40943
Published
Jul 12, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-362, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 12, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=2.6.23
  2. Affected versionversion=b25801038da5823bba1b5440a57ca68afc51b6bd <050ce8af6838c71e872e982b50d3f1bec21da40e
  3. Affected versionversion=b25801038da5823bba1b5440a57ca68afc51b6bd <117b9c009b72a6c2ebfd23484354dfee2d9570d2
  4. Affected versionversion=b25801038da5823bba1b5440a57ca68afc51b6bd <38825ff9da91d2854dcf6d9ac320a7e641e10f25
  5. Affected versionversion=b25801038da5823bba1b5440a57ca68afc51b6bd <3c26b5d21b1239e9c7fd31ba7d9b2d7bdbaa68d9
  6. Affected versionversion=b25801038da5823bba1b5440a57ca68afc51b6bd <3c361f313d696df72f9bccf058510e9ec737b9b1
  7. Affected versionversion=b25801038da5823bba1b5440a57ca68afc51b6bd <952b023f06a24b2ad6ba67304c4c84d45bea2f18
  8. Affected versionversion=b25801038da5823bba1b5440a57ca68afc51b6bd <e8e2db1adac47970a6a9225f3858e9aa0e86287f
  9. Affected versionversion=b25801038da5823bba1b5440a57ca68afc51b6bd <ea042dc2bea19d72e37c298bf65a9c341ef3fff3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.23; version=b25801038da5823bba1b5440a57ca68afc51b6bd <050ce8af6838c71e872e982b50d3f1bec21da40e; version=b25801038da5823bba1b5440a57ca68afc51b6bd <117b9c009b72a6c2ebfd23484354dfee2d9570d2; version=b25801038da5823bba1b5440a57ca68afc51b6bd <38825ff9da91d2854dcf6d9ac320a7e641e10f25; version=b25801038da5823bba1b5440a57ca68afc51b6bd <3c26b5d21b1239e9c7fd31ba7d9b2d7bdbaa68d9; version=b25801038da5823bba1b5440a57ca68afc51b6bd <3c361f313d696df72f9bccf058510e9ec737b9b1; version=b25801038da5823bba1b5440a57ca68afc51b6bd <952b023f06a24b2ad6ba67304c4c84d45bea2f18; version=b25801038da5823bba1b5440a57ca68afc51b6bd <e8e2db1adac47970a6a9225f3858e9aa0e86287f; version=b25801038da5823bba1b5440a57ca68afc51b6bd <ea042dc2bea19d72e37c298bf65a9c341ef3fff3

Published CVSS scores

4.7NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
T1499Endpoint Denial of Service

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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