CVE-2025-21951

System hang via contended device lock

Published Apr 1, 2025 · Updated May 11, 2026

Improper locking in the MHI PCI host driver in Linux allows local users to encounter a system hang during shutdown or suspend. The recovery_work handler calls pci_reset_function(), which waits for device_lock even when the power-management caller holds that lock and synchronously waits for recovery to finish. The deadlock requires an MHI PCI device to become unresponsive; Ubuntu reports that attackers cannot reliably invoke or influence that hardware condition, limiting the consequence to an availability interruption.

CVSS severity5.5
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

Improper locking in the MHI PCI host driver in Linux allows local users to encounter a system hang during shutdown or suspend. The recovery_work handler calls pci_reset_function(), which waits for device_lock even when the power-management caller holds that lock and synchronously waits for recovery to finish. The deadlock requires an MHI PCI device to become unresponsive; Ubuntu reports that attackers cannot reliably invoke or influence that hardware condition, limiting the consequence to an availability interruption.

The record

CVE
CVE-2025-21951
Published
Apr 1, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-667
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 1, 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=5.12
  2. Affected versionversion=7389337f0a78ea099c47f0af08f64f20c52ab4ba <1f9eb7078bc6b5fb5cbfbcb37c4bc01685332b95
  3. Affected versionversion=7389337f0a78ea099c47f0af08f64f20c52ab4ba <62505657475c245c9cd46e42ac01026d1e61f027
  4. Affected versionversion=7389337f0a78ea099c47f0af08f64f20c52ab4ba <7746f3bb8917fccb4571a576f3837d80fc513054
  5. Affected versionversion=7389337f0a78ea099c47f0af08f64f20c52ab4ba <7a5ffadd54fe2662f5c99cdccf30144d060376f7
  6. Affected versionversion=7389337f0a78ea099c47f0af08f64f20c52ab4ba <985d3cf56d8745ca637deee273929e01df449f85
  7. Affected versionversion=7389337f0a78ea099c47f0af08f64f20c52ab4ba <a321d163de3d8aa38a6449ab2becf4b1581aed96

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.12; version=7389337f0a78ea099c47f0af08f64f20c52ab4ba <1f9eb7078bc6b5fb5cbfbcb37c4bc01685332b95; version=7389337f0a78ea099c47f0af08f64f20c52ab4ba <62505657475c245c9cd46e42ac01026d1e61f027; version=7389337f0a78ea099c47f0af08f64f20c52ab4ba <7746f3bb8917fccb4571a576f3837d80fc513054; version=7389337f0a78ea099c47f0af08f64f20c52ab4ba <7a5ffadd54fe2662f5c99cdccf30144d060376f7; version=7389337f0a78ea099c47f0af08f64f20c52ab4ba <985d3cf56d8745ca637deee273929e01df449f85; version=7389337f0a78ea099c47f0af08f64f20c52ab4ba <a321d163de3d8aa38a6449ab2becf4b1581aed96

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.

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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

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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