CVE-2021-47382

System hang via qeth recovery deadlock

Published May 21, 2024 · Updated May 23, 2026

Deadlock in the s390 qeth driver in affected Linux kernel releases allows local users to hang the system during failed recovery. The qeth_do_reset() error path reacquires discipline_mutex while racing with ccwgroup_remove instead of taking the device offline without that mutex. Exploitation requires local low-privileged access, an s390 system with a qeth device, and the timing-sensitive offline and reset race.

CVSS severity4.7
Medium
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deadlock in the s390 qeth driver in affected Linux kernel releases allows local users to hang the system during failed recovery. The qeth_do_reset() error path reacquires discipline_mutex while racing with ccwgroup_remove instead of taking the device offline without that mutex. Exploitation requires local low-privileged access, an s390 system with a qeth device, and the timing-sensitive offline and reset race.

The record

CVE
CVE-2021-47382
Published
May 21, 2024
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-667, CWE-362
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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.10.8 <5.11
  2. Affected versionversion=5.11
  3. Affected versionversion=af0c184ea106051e428b5a0b5f2dfd31cbc54c52
  4. Affected versionversion=b41b554c1ee75070a14c02a88496b1f231c7eacc <0bfe741741327822d1482c7edef0184636d08b40
  5. Affected versionversion=b41b554c1ee75070a14c02a88496b1f231c7eacc <d2b59bd4b06d84a4eadb520b0f71c62fe8ec0a62

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.10.8 <5.11; version=5.11; version=af0c184ea106051e428b5a0b5f2dfd31cbc54c52; version=b41b554c1ee75070a14c02a88496b1f231c7eacc <0bfe741741327822d1482c7edef0184636d08b40; version=b41b554c1ee75070a14c02a88496b1f231c7eacc <d2b59bd4b06d84a4eadb520b0f71c62fe8ec0a62

Published CVSS scores

4.7NIST NVDCVSS:3.1/AV:L/AC:H/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-667Improper Locking
CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

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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