CVE-2023-52737

Local task hang via missing Btrfs inode lock

Published May 21, 2024 · Updated Jun 1, 2026

Improper locking in the Linux kernel's Btrfs implementation allows local users to hang tasks through concurrent fiemap and fsync operations. The Btrfs fiemap path locks only an inode I/O-tree range, so a user-buffer page fault can deadlock with fsync on i_mmap_lock. A local user must race fiemap against fsync on the same Btrfs file; successful triggering leaves affected tasks blocked indefinitely.

CVSS severity5.5
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper locking in the Linux kernel's Btrfs implementation allows local users to hang tasks through concurrent fiemap and fsync operations. The Btrfs fiemap path locks only an inode I/O-tree range, so a user-buffer page fault can deadlock with fsync on i_mmap_lock. A local user must race fiemap against fsync on the same Btrfs file; successful triggering leaves affected tasks blocked indefinitely.

The record

CVE
CVE-2023-52737
Published
May 21, 2024
Updated
Jun 1, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-667, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2024CVE publishedPublication date reported by the CVE source.
  2. Jun 1, 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=5.13
  2. Affected versionversion=885f46d87f29a94eafe3cc707d5c4dea2be248f3 <519b7e13b5ae8dd38da1e52275705343be6bb508
  3. Affected versionversion=885f46d87f29a94eafe3cc707d5c4dea2be248f3 <d8c594da79bc0244e610a70594e824a401802be1
  4. Affected versionversion=885f46d87f29a94eafe3cc707d5c4dea2be248f3 <e425191073a80906d8502b5179471cc58b0b9e9a

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.13; version=885f46d87f29a94eafe3cc707d5c4dea2be248f3 <519b7e13b5ae8dd38da1e52275705343be6bb508; version=885f46d87f29a94eafe3cc707d5c4dea2be248f3 <d8c594da79bc0244e610a70594e824a401802be1; version=885f46d87f29a94eafe3cc707d5c4dea2be248f3 <e425191073a80906d8502b5179471cc58b0b9e9a

Published CVSS scores

5.5CanonicalCVSS: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-667Improper Locking
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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