CVE-2021-47369

System crash via unallocated qeth queue dereference

Published May 21, 2024 · Updated May 23, 2026

NULL pointer dereference in the Linux kernel allows local users to crash s390 systems during qeth network-device setup. qeth_clear_working_pool_list() uses card->qdio.in_q after setup fails before queue allocation, then writes through the null queue pointer into CPU lowcore memory. Reaching the crash requires local device-management access and an early I/O error, mismatched transport mode, bad port number, or rare queue reallocation failure.

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

NULL pointer dereference in the Linux kernel allows local users to crash s390 systems during qeth network-device setup. qeth_clear_working_pool_list() uses card->qdio.in_q after setup fails before queue allocation, then writes through the null queue pointer into CPU lowcore memory. Reaching the crash requires local device-management access and an early I/O error, mismatched transport mode, bad port number, or rare queue reallocation failure.

The record

CVE
CVE-2021-47369
Published
May 21, 2024
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2024CVE 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=22697ca855c06a4a1264d5651542b7d98870a8c4
  2. Affected versionversion=5.7.16 <5.8
  3. Affected versionversion=5.8.2 <5.9
  4. Affected versionversion=5.9
  5. Affected versionversion=b2400fe7e1011c5f3dc2268e8382082465b1c8a2
  6. Affected versionversion=eff73e16ee116f6eafa2be48fab42659a27cb453 <248f064af222a1f97ee02c84a98013dfbccad386
  7. Affected versionversion=eff73e16ee116f6eafa2be48fab42659a27cb453 <9b00fb12cdc9d8d1c3ffe82a78e74738127803fc
  8. Affected versionversion=eff73e16ee116f6eafa2be48fab42659a27cb453 <db94f89e1dadf693c15c2d60de0c34777cea5779

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=22697ca855c06a4a1264d5651542b7d98870a8c4; version=5.7.16 <5.8; version=5.8.2 <5.9; version=5.9; version=b2400fe7e1011c5f3dc2268e8382082465b1c8a2; version=eff73e16ee116f6eafa2be48fab42659a27cb453 <248f064af222a1f97ee02c84a98013dfbccad386; version=eff73e16ee116f6eafa2be48fab42659a27cb453 <9b00fb12cdc9d8d1c3ffe82a78e74738127803fc; version=eff73e16ee116f6eafa2be48fab42659a27cb453 <db94f89e1dadf693c15c2d60de0c34777cea5779
The Linux Kernel Organization · Linux Kernelversion=5.9; version=eff73e16ee11 <248f064af222; version=eff73e16ee11 <9b00fb12cdc9; version=eff73e16ee11 <db94f89e1dad

Published CVSS scores

5.5CISA ADP VulnrichmentCVSS: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-476NULL Pointer Dereference
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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