CVE-2021-47449

Teardown hang via sleeping mutex under spinlock

Published May 22, 2024 · Updated May 11, 2026

Deadlock in the Linux kernel ICE driver 5.14.4 through 5.14.13 allows local users to hang device teardown during driver removal. The Tx timestamp flush path holds a spinlock while ice_clear_phy_tstamp acquires a mutex to send a PHY firmware command, allowing a sleep in atomic context. Triggering the condition requires local access and authority to remove the ICE driver or device; the bounded consequence is a teardown hang.

CVSS severity7.1
High
EPSS probability0.20%
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 Linux kernel ICE driver 5.14.4 through 5.14.13 allows local users to hang device teardown during driver removal. The Tx timestamp flush path holds a spinlock while ice_clear_phy_tstamp acquires a mutex to send a PHY firmware command, allowing a sleep in atomic context. Triggering the condition requires local access and authority to remove the ICE driver or device; the bounded consequence is a teardown hang.

The record

CVE
CVE-2021-47449
Published
May 22, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-129, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 22, 2024CVE 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=46720ac66c21bf85e08823664b7b314b85e43f26 <61616be899975404df44c20ab902464b60882cd7
  2. Affected versionversion=4dd0d5c33c3ebf24a07cae6141648aeb7ba56072 <4d4a223a86afe658cd878800f09458e8bb54415d
  3. Affected versionversion=5.14.4 <5.14.14

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=46720ac66c21bf85e08823664b7b314b85e43f26 <61616be899975404df44c20ab902464b60882cd7; version=4dd0d5c33c3ebf24a07cae6141648aeb7ba56072 <4d4a223a86afe658cd878800f09458e8bb54415d; version=5.14.4 <5.14.14
The Linux Kernel Organization · Linux Kernelversion=5.14.4 <5.14.14

Published CVSS scores

7.1CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/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

CWE-129Improper Validation of Array Index
T1499Endpoint Denial of Service

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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