CVE-2021-47229

Kernel panic via overlapping Aardvark PIO transfers

Published May 21, 2024 · Updated May 11, 2026

Denial of service in the Linux Aardvark PCI controller allows local users to trigger a kernel panic during PIO transfers. The driver writes a new request to PIO_START while the preceding transfer still reports busy, causing a CPU External Abort rather than rejecting the overlap. Reachability requires an Aardvark PCI controller and a delayed prior transfer, commonly during link retraining or after link loss; the bounded result is a host crash.

CVSS severity5.5
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Denial of service in the Linux Aardvark PCI controller allows local users to trigger a kernel panic during PIO transfers. The driver writes a new request to PIO_START while the preceding transfer still reports busy, causing a CPU External Abort rather than rejecting the overlap. Reachability requires an Aardvark PCI controller and a delayed prior transfer, commonly during link retraining or after link loss; the bounded result is a host crash.

The record

CVE
CVE-2021-47229
Published
May 21, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.8
  2. Affected versionversion=8c39d710363c14ecb09219332869707395d1d495 <1a1dbc4473974867fe8c5f195c17b341c8e82867
  3. Affected versionversion=8c39d710363c14ecb09219332869707395d1d495 <3d213a4ddf49a860be6e795482c17f87e0c82b2a
  4. Affected versionversion=8c39d710363c14ecb09219332869707395d1d495 <400e6b1860c8be61388d0b77814c53260f96e17a
  5. Affected versionversion=8c39d710363c14ecb09219332869707395d1d495 <4c90f90a91d75c3c73dd633827c90e8746d9f54d
  6. Affected versionversion=8c39d710363c14ecb09219332869707395d1d495 <b00a9aaa4be20ad6e3311fb78a485eae0899e89a
  7. Affected versionversion=8c39d710363c14ecb09219332869707395d1d495 <f18139966d072dab8e4398c95ce955a9742e04f7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.8; version=8c39d710363c14ecb09219332869707395d1d495 <1a1dbc4473974867fe8c5f195c17b341c8e82867; version=8c39d710363c14ecb09219332869707395d1d495 <3d213a4ddf49a860be6e795482c17f87e0c82b2a; version=8c39d710363c14ecb09219332869707395d1d495 <400e6b1860c8be61388d0b77814c53260f96e17a; version=8c39d710363c14ecb09219332869707395d1d495 <4c90f90a91d75c3c73dd633827c90e8746d9f54d; version=8c39d710363c14ecb09219332869707395d1d495 <b00a9aaa4be20ad6e3311fb78a485eae0899e89a; version=8c39d710363c14ecb09219332869707395d1d495 <f18139966d072dab8e4398c95ce955a9742e04f7

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.

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

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo