CVE-2021-47195

Kernel crash via post-release mutex unlock

Published Apr 10, 2024 · Updated May 23, 2026

Use-after-free in the Linux SPI core 5.14.15 through 5.15.4 allows local users to crash the kernel during controller removal. spi_unregister_controller calls put_device, allowing spi_controller_release to free the controller before mutex_unlock accesses its add_lock member. Exploitation requires local low-privileged access and a reachable SPI controller-removal path; the bounded consequence is a kernel crash and service interruption.

CVSS severity5.5
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux SPI core 5.14.15 through 5.15.4 allows local users to crash the kernel during controller removal. spi_unregister_controller calls put_device, allowing spi_controller_release to free the controller before mutex_unlock accesses its add_lock member. Exploitation requires local low-privileged access and a reachable SPI controller-removal path; the bounded consequence is a kernel crash and service interruption.

The record

CVE
CVE-2021-47195
Published
Apr 10, 2024
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 10, 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

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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=5.14.15 <5.15
  2. Affected versionversion=5.15
  3. Affected versionversion=6098475d4cb48d821bdf453c61118c56e26294f0 <37330f37f6666c7739a44b2b6b95b047ccdbed2d
  4. Affected versionversion=6098475d4cb48d821bdf453c61118c56e26294f0 <6c53b45c71b4920b5e62f0ea8079a1da382b9434
  5. Affected versionversion=722ef19a161ce3fffb3d1b01ce2301c306639bdd
  6. Affected versionversion=aa3f3d7bef59583f2d3234173105a27ff61ef8fe <54c2c96eafcfd242e52e932ab54ace4784efe1dd
  7. Affected versionversion=c8dce228db6f81dbc897a018dfc5c418e917cf64 <11eab327a2a8bd36c38afbff920ae1bd45588dd4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.14.15 <5.15; version=5.15; version=6098475d4cb48d821bdf453c61118c56e26294f0 <37330f37f6666c7739a44b2b6b95b047ccdbed2d; version=6098475d4cb48d821bdf453c61118c56e26294f0 <6c53b45c71b4920b5e62f0ea8079a1da382b9434; version=722ef19a161ce3fffb3d1b01ce2301c306639bdd; version=aa3f3d7bef59583f2d3234173105a27ff61ef8fe <54c2c96eafcfd242e52e932ab54ace4784efe1dd; version=c8dce228db6f81dbc897a018dfc5c418e917cf64 <11eab327a2a8bd36c38afbff920ae1bd45588dd4

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-416Use After Free
T1499.004Application or System Exploitation

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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