CVE-2022-49097

Local writeback hang via blocking mempool allocation

Published Feb 26, 2025 · Updated May 11, 2026

Infinite-loop denial of service in Linux kernel NFS allows local users to hang writeback threads during low-memory writeback. The NFS writeback allocation paths in fs/nfs/pagelist.c and fs/nfs/write.c use blocking mempool_alloc() calls, so workers wait indefinitely when depleted pools cannot be replenished. Triggering requires local access, NFS-backed writes, and memory pressure; the bounded consequence is stalled NFS writeback and loss of I/O availability.

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

Infinite-loop denial of service in Linux kernel NFS allows local users to hang writeback threads during low-memory writeback. The NFS writeback allocation paths in fs/nfs/pagelist.c and fs/nfs/write.c use blocking mempool_alloc() calls, so workers wait indefinitely when depleted pools cannot be replenished. Triggering requires local access, NFS-backed writes, and memory pressure; the bounded consequence is stalled NFS writeback and loss of I/O availability.

The record

CVE
CVE-2022-49097
Published
Feb 26, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-835, 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=2b17d725f9be59a1bfa0583af690c463fca1f385 <0bae835b63c53f86cdc524f5962e39409585b22c
  2. Affected versionversion=2b17d725f9be59a1bfa0583af690c463fca1f385 <1b3fa9a3c420c31e77b406ddc28f3a627100516c
  3. Affected versionversion=2b17d725f9be59a1bfa0583af690c463fca1f385 <a6caeddd68977a1aaaf62fbd1955b41dd5c3c5d3
  4. Affected versionversion=2b17d725f9be59a1bfa0583af690c463fca1f385 <c74e2f6ecc51bd08bb5b0335477dba954a50592e
  5. Affected versionversion=2b17d725f9be59a1bfa0583af690c463fca1f385 <ea029e4ce760f786919d06ef52efa2e50ea92a5f
  6. Affected versionversion=5.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2b17d725f9be59a1bfa0583af690c463fca1f385 <0bae835b63c53f86cdc524f5962e39409585b22c; version=2b17d725f9be59a1bfa0583af690c463fca1f385 <1b3fa9a3c420c31e77b406ddc28f3a627100516c; version=2b17d725f9be59a1bfa0583af690c463fca1f385 <a6caeddd68977a1aaaf62fbd1955b41dd5c3c5d3; version=2b17d725f9be59a1bfa0583af690c463fca1f385 <c74e2f6ecc51bd08bb5b0335477dba954a50592e; version=2b17d725f9be59a1bfa0583af690c463fca1f385 <ea029e4ce760f786919d06ef52efa2e50ea92a5f; version=5.3

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-835Loop with Unreachable Exit Condition ('Infinite Loop')
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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