CVE-2022-49079

Local service hang via recursive mutex acquisition

Published Feb 26, 2025 · Updated May 11, 2026

Improper locking in Linux kernel 5.16 through 5.16.19 and 5.17 through 5.17.2 allows local users to hang Btrfs allocation. btrfs_can_activate_zone() reacquires device_list_mutex while the same chunk-allocation path already holds it, recursively blocking the worker. Reachability requires a zoned Btrfs filesystem and local activity that drives extent reservation into chunk allocation; the resulting deadlock interrupts filesystem service.

CVSS severity5.5
Medium
EPSS probability0.18%
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 Linux kernel 5.16 through 5.16.19 and 5.17 through 5.17.2 allows local users to hang Btrfs allocation. btrfs_can_activate_zone() reacquires device_list_mutex while the same chunk-allocation path already holds it, recursively blocking the worker. Reachability requires a zoned Btrfs filesystem and local activity that drives extent reservation into chunk allocation; the resulting deadlock interrupts filesystem service.

The record

CVE
CVE-2022-49079
Published
Feb 26, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-667, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 26, 2025CVE 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

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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=5.16
  2. Affected versionversion=a85f05e59bc15a83ad910dbcb71df5ad8fa77295 <09e65ae515af2b24d6dc23af21719a3b41de83e5
  3. Affected versionversion=a85f05e59bc15a83ad910dbcb71df5ad8fa77295 <0b9e66762aa0cda2a9c2d5542d64e04dac528fa6
  4. Affected versionversion=a85f05e59bc15a83ad910dbcb71df5ad8fa77295 <142f822bd945a7be442a2916ec6167cc102c4183

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.16; version=a85f05e59bc15a83ad910dbcb71df5ad8fa77295 <09e65ae515af2b24d6dc23af21719a3b41de83e5; version=a85f05e59bc15a83ad910dbcb71df5ad8fa77295 <0b9e66762aa0cda2a9c2d5542d64e04dac528fa6; version=a85f05e59bc15a83ad910dbcb71df5ad8fa77295 <142f822bd945a7be442a2916ec6167cc102c4183

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

CWE-667Improper Locking
T1499.004Application or System Exploitation

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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