CVE-2021-47212

Service interruption via mlx5 teardown error handling

Published Apr 10, 2024 · Updated May 11, 2026

Denial of service in the mlx5 driver in Linux 5.2 through 5.15.4 and 5.16-rc1 allows local users to trigger a kernel call trace. During fast device unload, the command handler wrongly returns EIO for DESTROY_UCTX and DESTROY_UMEM after the internal-error state marks teardown as started. Reaching the fault requires local access and an mlx5 RDMA device; the documented consequence is an error trace during UMEM release and availability loss.

CVSS severity5.5
Medium
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

Denial of service in the mlx5 driver in Linux 5.2 through 5.15.4 and 5.16-rc1 allows local users to trigger a kernel call trace. During fast device unload, the command handler wrongly returns EIO for DESTROY_UCTX and DESTROY_UMEM after the internal-error state marks teardown as started. Reaching the fault requires local access and an mlx5 RDMA device; the documented consequence is an error trace during UMEM release and availability loss.

The record

CVE
CVE-2021-47212
Published
Apr 10, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 10, 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=5.2
  2. Affected versionversion=6a6fabbfa3e8c656ff906ae999fb6856410fa4cd <a51a6da375d82aed5c8f83abd13e7d060421bd48
  3. Affected versionversion=6a6fabbfa3e8c656ff906ae999fb6856410fa4cd <ba50cd9451f6c49cf0841c0a4a146ff6a2822699

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.2; version=6a6fabbfa3e8c656ff906ae999fb6856410fa4cd <a51a6da375d82aed5c8f83abd13e7d060421bd48; version=6a6fabbfa3e8c656ff906ae999fb6856410fa4cd <ba50cd9451f6c49cf0841c0a4a146ff6a2822699

Published CVSS scores

4.4Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
5.5NVDCVSS: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

No sourced classifications are available.

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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