CVE-2022-49068

Local denial of service via delalloc under-release

Published Feb 26, 2025 · Updated May 23, 2026

Resource-accounting error in the Linux btrfs direct I/O path allows local users to interrupt service through a constrained-space write. In btrfs_get_blocks_direct_write(), the copy-on-write path shortens len after reserving delalloc extents, then releases extents using the shortened value. A 1 GiB btrfs filesystem that forces a short write reproduces the flaw, leaving outstanding extents that trigger a kernel warning during inode destruction.

CVSS severity5.5
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource-accounting error in the Linux btrfs direct I/O path allows local users to interrupt service through a constrained-space write. In btrfs_get_blocks_direct_write(), the copy-on-write path shortens len after reserving delalloc extents, then releases extents using the shortened value. A 1 GiB btrfs filesystem that forces a short write reproduces the flaw, leaving outstanding extents that trigger a kernel warning during inode destruction.

The record

CVE
CVE-2022-49068
Published
Feb 26, 2025
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 26, 2025CVE 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=5.15.27 <5.15.35
  2. Affected versionversion=5.16.13 <5.17
  3. Affected versionversion=5.17
  4. Affected versionversion=5afd80c393f4e87451f14eefb7f2f24daf434e06 <07cacfd9d9dc134557ac8866c73d570a59b3d1f3
  5. Affected versionversion=96f1be29492d9e2fb97bb27f824478ab8cd3ab86
  6. Affected versionversion=f0bfa76a11e93d0fe2c896fcb566568c5e8b5d3f <6d82ad13c4110e73c7b0392f00534a1502a1b520
  7. Affected versionversion=f0bfa76a11e93d0fe2c896fcb566568c5e8b5d3f <a04d37ddfe4be431b9e52e8504490376ab0a39a4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.15.27 <5.15.35; version=5.16.13 <5.17; version=5.17; version=5afd80c393f4e87451f14eefb7f2f24daf434e06 <07cacfd9d9dc134557ac8866c73d570a59b3d1f3; version=96f1be29492d9e2fb97bb27f824478ab8cd3ab86; version=f0bfa76a11e93d0fe2c896fcb566568c5e8b5d3f <6d82ad13c4110e73c7b0392f00534a1502a1b520; version=f0bfa76a11e93d0fe2c896fcb566568c5e8b5d3f <a04d37ddfe4be431b9e52e8504490376ab0a39a4

Published CVSS scores

5.5NVDCVSS: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

T1499.004Application 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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