CVE-2025-38671

Kernel hang via incomplete I2C timeout handling

Published Aug 22, 2025 · Updated May 11, 2026

Denial of service in the Linux QUP I2C driver allows local users to hang the kernel through an I2C client that keeps the bus active. The timeout path in drivers/i2c/busses/i2c-qup.c sets an error result but remains in its polling loop instead of returning ETIMEDOUT. Triggering the flaw requires local low-privileged access and an active QUP-controlled I2C bus; the bounded consequence is a kernel hang.

CVSS severity5.5
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the Linux QUP I2C driver allows local users to hang the kernel through an I2C client that keeps the bus active. The timeout path in drivers/i2c/busses/i2c-qup.c sets an error result but remains in its polling loop instead of returning ETIMEDOUT. Triggering the flaw requires local low-privileged access and an active QUP-controlled I2C bus; the bounded consequence is a kernel hang.

The record

CVE
CVE-2025-38671
Published
Aug 22, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 22, 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=4.17
  2. Affected versionversion=fbfab1ab065879370541caf0e514987368eb41b2 <0d33913fce67a93c1eb83396c3c9d6b411dcab33
  3. Affected versionversion=fbfab1ab065879370541caf0e514987368eb41b2 <42c4471b30fa203249f476dd42321cd7efb7f6a8
  4. Affected versionversion=fbfab1ab065879370541caf0e514987368eb41b2 <89459f168b78e5c801dc8b7ad037b62898bc4f57
  5. Affected versionversion=fbfab1ab065879370541caf0e514987368eb41b2 <a7982a14b3012527a9583d12525cd0dc9f8d8934
  6. Affected versionversion=fbfab1ab065879370541caf0e514987368eb41b2 <acfa2948be630ad857535cb36153697f3cbf9ca9
  7. Affected versionversion=fbfab1ab065879370541caf0e514987368eb41b2 <c523bfba46c4b4d7676fb050909533a766698ecd
  8. Affected versionversion=fbfab1ab065879370541caf0e514987368eb41b2 <cbec4406998185e0311ae97dfacc649f9cd79b0b
  9. Affected versionversion=fbfab1ab065879370541caf0e514987368eb41b2 <d05ec13aa3eb868a60dc961b489053a643863ddc

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.17; version=fbfab1ab065879370541caf0e514987368eb41b2 <0d33913fce67a93c1eb83396c3c9d6b411dcab33; version=fbfab1ab065879370541caf0e514987368eb41b2 <42c4471b30fa203249f476dd42321cd7efb7f6a8; version=fbfab1ab065879370541caf0e514987368eb41b2 <89459f168b78e5c801dc8b7ad037b62898bc4f57; version=fbfab1ab065879370541caf0e514987368eb41b2 <a7982a14b3012527a9583d12525cd0dc9f8d8934; version=fbfab1ab065879370541caf0e514987368eb41b2 <acfa2948be630ad857535cb36153697f3cbf9ca9; version=fbfab1ab065879370541caf0e514987368eb41b2 <c523bfba46c4b4d7676fb050909533a766698ecd; version=fbfab1ab065879370541caf0e514987368eb41b2 <cbec4406998185e0311ae97dfacc649f9cd79b0b; version=fbfab1ab065879370541caf0e514987368eb41b2 <d05ec13aa3eb868a60dc961b489053a643863ddc

Published CVSS scores

5.5CanonicalCVSS: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 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

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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