CVE-2023-53233

System hang via synchronous SMC work cancellation

Published Sep 15, 2025 · Updated Sep 15, 2025

Improper locking in Linux kernel SMC 5.8 through 6.2 allows local users to hang the system by initiating an SMC connection. __smc_lgr_terminate() synchronously cancels free_work while that work can hold a completion lock and wait through SMC transmit work, creating a circular dependency during workqueue destruction. A local low-privilege user must reach the SMC connect path during link-group cleanup; the deadlock blocks kernel work and causes system-wide availability loss.

CVSS severity5.5
Medium
EPSS probability0.12%
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 SMC 5.8 through 6.2 allows local users to hang the system by initiating an SMC connection. __smc_lgr_terminate() synchronously cancels free_work while that work can hold a completion lock and wait through SMC transmit work, creating a circular dependency during workqueue destruction. A local low-privilege user must reach the SMC connect path during link-group cleanup; the deadlock blocks kernel work and causes system-wide availability loss.

The record

CVE
CVE-2023-53233
Published
Sep 15, 2025
Updated
Sep 15, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-667, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 15, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 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=5.8
  2. Affected versionversion=a52bcc919b14c9d78f03b2b4ff604e5ca69c7e6d <13085e1b5cab8ad802904d72e6a6dae85ae0cd20
  3. Affected versionversion=a52bcc919b14c9d78f03b2b4ff604e5ca69c7e6d <3517584cf1b35bd02f4a90267ddf9dcf17bd9c87
  4. Affected versionversion=a52bcc919b14c9d78f03b2b4ff604e5ca69c7e6d <9708efad9ba5095b9bb7916e11a135b3bd66c071
  5. Affected versionversion=a52bcc919b14c9d78f03b2b4ff604e5ca69c7e6d <b615238e5bc01e13dc0610febddc1ca99bab1df6
  6. Affected versionversion=a52bcc919b14c9d78f03b2b4ff604e5ca69c7e6d <c9ca2257150272df1b8d9ebe5059197ffea6e913

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.8; version=a52bcc919b14c9d78f03b2b4ff604e5ca69c7e6d <13085e1b5cab8ad802904d72e6a6dae85ae0cd20; version=a52bcc919b14c9d78f03b2b4ff604e5ca69c7e6d <3517584cf1b35bd02f4a90267ddf9dcf17bd9c87; version=a52bcc919b14c9d78f03b2b4ff604e5ca69c7e6d <9708efad9ba5095b9bb7916e11a135b3bd66c071; version=a52bcc919b14c9d78f03b2b4ff604e5ca69c7e6d <b615238e5bc01e13dc0610febddc1ca99bab1df6; version=a52bcc919b14c9d78f03b2b4ff604e5ca69c7e6d <c9ca2257150272df1b8d9ebe5059197ffea6e913

Published CVSS scores

5.5CISA ADPCVSS: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

CWE-667Improper Locking
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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