CVE-2021-47114

File corruption via OCFS2 fallocate writeback race

Published Mar 15, 2024 · Updated May 11, 2026

Data corruption in Linux kernel OCFS2 before 5.13 allows local users to corrupt files through concurrent fallocate and writeback. The race occurs when a hole beyond inode size is zeroed before i_size is extended, letting ocfs2_writepage drop pages outside the stale size. Triggering it requires write access to an OCFS2 file and concurrent writeback; the result is corruption of that file rather than code execution.

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

Data corruption in Linux kernel OCFS2 before 5.13 allows local users to corrupt files through concurrent fallocate and writeback. The race occurs when a hole beyond inode size is zeroed before i_size is extended, letting ocfs2_writepage drop pages outside the stale size. Triggering it requires write access to an OCFS2 file and concurrent writeback; the result is corruption of that file rather than code execution.

The record

CVE
CVE-2021-47114
Published
Mar 15, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 15, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

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=385820a38d5e7c70b20af4d68767b1920b1e4133 <0a31dd6fd2f4e7db538fb6eb1f06973d81f8dd3b
  3. Affected versionversion=385820a38d5e7c70b20af4d68767b1920b1e4133 <33e03adafb29eedae1bae9cdb50c1385279fcf65
  4. Affected versionversion=385820a38d5e7c70b20af4d68767b1920b1e4133 <624fa7baa3788dc9e57840ba5b94bc22b03cda57
  5. Affected versionversion=385820a38d5e7c70b20af4d68767b1920b1e4133 <6bba4471f0cc1296fe3c2089b9e52442d3074b2e
  6. Affected versionversion=385820a38d5e7c70b20af4d68767b1920b1e4133 <a1700479524bb9cb5e8ae720236a6fabd003acae
  7. Affected versionversion=385820a38d5e7c70b20af4d68767b1920b1e4133 <c8d5faee46242c3f33b8a71a4d7d52214785bfcc
  8. Affected versionversion=385820a38d5e7c70b20af4d68767b1920b1e4133 <cc2edb99ea606a45182b5ea38cc8f4e583aa0774
  9. Affected versionversion=385820a38d5e7c70b20af4d68767b1920b1e4133 <cec4e857ffaa8c447f51cd8ab4e72350077b6770

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.23; version=385820a38d5e7c70b20af4d68767b1920b1e4133 <0a31dd6fd2f4e7db538fb6eb1f06973d81f8dd3b; version=385820a38d5e7c70b20af4d68767b1920b1e4133 <33e03adafb29eedae1bae9cdb50c1385279fcf65; version=385820a38d5e7c70b20af4d68767b1920b1e4133 <624fa7baa3788dc9e57840ba5b94bc22b03cda57; version=385820a38d5e7c70b20af4d68767b1920b1e4133 <6bba4471f0cc1296fe3c2089b9e52442d3074b2e; version=385820a38d5e7c70b20af4d68767b1920b1e4133 <a1700479524bb9cb5e8ae720236a6fabd003acae; version=385820a38d5e7c70b20af4d68767b1920b1e4133 <c8d5faee46242c3f33b8a71a4d7d52214785bfcc; version=385820a38d5e7c70b20af4d68767b1920b1e4133 <cc2edb99ea606a45182b5ea38cc8f4e583aa0774; version=385820a38d5e7c70b20af4d68767b1920b1e4133 <cec4e857ffaa8c447f51cd8ab4e72350077b6770

Published CVSS scores

5.5CISA-ADPCVSS: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.

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

No sourced classifications are available.

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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