CVE-2022-49394

Indefinite I/O hang via unfrozen counter disable

Published Feb 26, 2025 · Updated May 23, 2026

Denial of service in the Linux kernel blk-iolatency controller allows local users to cause an indefinite block I/O hang via cgroups. The iolatency_pd_offline() path decrements the enable counter without freezing the request queue, leaking in-flight counts when it disables tracking during active I/O. Exploitation requires local low-privileged cgroup access, iolatency enabled only in a removable cgroup, concurrent I/O, and later throttling of a cgroup with a stuck count.

CVSS severity5.5
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the Linux kernel blk-iolatency controller allows local users to cause an indefinite block I/O hang via cgroups. The iolatency_pd_offline() path decrements the enable counter without freezing the request queue, leaking in-flight counts when it disables tracking during active I/O. Exploitation requires local low-privileged cgroup access, iolatency enabled only in a removable cgroup, concurrent I/O, and later throttling of a cgroup with a stuck count.

The record

CVE
CVE-2022-49394
Published
Feb 26, 2025
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
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=4.19.29 <4.19.247
  2. Affected versionversion=4.20.16 <4.21
  3. Affected versionversion=5.0
  4. Affected versionversion=6d482bc5697763eb1214f207286daa201b32d20a <515d077ee3085ae343b6bea7fd031f9906645f38
  5. Affected versionversion=8c772a9bfc7c07c76f4a58b58910452fbb20843b <5b0ff3ebbef791341695b718f8d2870869cf1d01
  6. Affected versionversion=8c772a9bfc7c07c76f4a58b58910452fbb20843b <77692c02e1517c54f2fd0535f41aa4286ac9f140
  7. Affected versionversion=8c772a9bfc7c07c76f4a58b58910452fbb20843b <8a177a36da6c54c98b8685d4f914cb3637d53c0d
  8. Affected versionversion=8c772a9bfc7c07c76f4a58b58910452fbb20843b <968f7a239c590454ffba79c126fbe0e963a0ba78
  9. Affected versionversion=8c772a9bfc7c07c76f4a58b58910452fbb20843b <a30acbb5dfb7bcc813ad6a18ca31011ac44e5547
  10. Affected versionversion=8c772a9bfc7c07c76f4a58b58910452fbb20843b <d19fa8f252000d141f9199ca32959c50314e1f05
  11. Affected versionversion=beed6109acd4efc2f1717c31bddcd0ad7ebbf253

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.19.29 <4.19.247; version=4.20.16 <4.21; version=5.0; version=6d482bc5697763eb1214f207286daa201b32d20a <515d077ee3085ae343b6bea7fd031f9906645f38; version=8c772a9bfc7c07c76f4a58b58910452fbb20843b <5b0ff3ebbef791341695b718f8d2870869cf1d01; version=8c772a9bfc7c07c76f4a58b58910452fbb20843b <77692c02e1517c54f2fd0535f41aa4286ac9f140; version=8c772a9bfc7c07c76f4a58b58910452fbb20843b <8a177a36da6c54c98b8685d4f914cb3637d53c0d; version=8c772a9bfc7c07c76f4a58b58910452fbb20843b <968f7a239c590454ffba79c126fbe0e963a0ba78; version=8c772a9bfc7c07c76f4a58b58910452fbb20843b <a30acbb5dfb7bcc813ad6a18ca31011ac44e5547; version=8c772a9bfc7c07c76f4a58b58910452fbb20843b <d19fa8f252000d141f9199ca32959c50314e1f05; version=beed6109acd4efc2f1717c31bddcd0ad7ebbf253

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

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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