CVE-2022-50839

Local denial of service via buffer-reference leak

Published Dec 30, 2025 · Updated Dec 30, 2025

A JBD2 reference-count leak in Linux allows local users to deplete kernel memory through fast-commit I/O errors. jbd2_fc_wait_bufs returns -EIO for a non-uptodate buffer without advancing journal->j_fc_off, causing jbd2_fc_release_bufs to stop early and retain buffer-head references. The path requires an ext4 filesystem created with fast commits enabled and a failed fast-commit buffer I/O; repeated leaks can interrupt service by exhausting kernel memory.

CVSS severity5.5
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A JBD2 reference-count leak in Linux allows local users to deplete kernel memory through fast-commit I/O errors. jbd2_fc_wait_bufs returns -EIO for a non-uptodate buffer without advancing journal->j_fc_off, causing jbd2_fc_release_bufs to stop early and retain buffer-head references. The path requires an ext4 filesystem created with fast commits enabled and a failed fast-commit buffer I/O; repeated leaks can interrupt service by exhausting kernel memory.

The record

CVE
CVE-2022-50839
Published
Dec 30, 2025
Updated
Dec 30, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 30, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 30, 2025Record 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <68ed9c76b2affd47177b92495446abb7262d0ef7
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7a33dde572fceb45d02d188e0213c47059401c93
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9b073d73725366d886b711b74e058c02f51e7a0e
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e0d5fc7a6d80ac2406c7dfc6bb625201d0250a8a
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e7385c868ee038d6a0cb0e85c22d2741e7910fd5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <68ed9c76b2affd47177b92495446abb7262d0ef7; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7a33dde572fceb45d02d188e0213c47059401c93; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9b073d73725366d886b711b74e058c02f51e7a0e; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e0d5fc7a6d80ac2406c7dfc6bb625201d0250a8a; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e7385c868ee038d6a0cb0e85c22d2741e7910fd5

Published CVSS scores

5.5Amazon LinuxCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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.

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Technologies

Your stack

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Your stack

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