CVE-2021-47140

Kernel crash via stale AMD IOMMU DMA ops

Published Mar 25, 2024 · Updated May 11, 2026

Denial of service in the Linux kernel 5.11 allows local users to crash the kernel by switching an AMD IOMMU group to identity mode. When iommu_change_dev_def_domain() reprobes a device, the AMD probe_finalize() path leaves dev->dma_ops pointing to dma-iommu operations after the domain becomes identity. Reaching the fault requires permission to change the IOMMU group type and rebind a PCI device; the next DMA allocation dereferences invalid state and produces a kernel oops.

CVSS severity5.3
Medium
EPSS probability0.60%
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 kernel 5.11 allows local users to crash the kernel by switching an AMD IOMMU group to identity mode. When iommu_change_dev_def_domain() reprobes a device, the AMD probe_finalize() path leaves dev->dma_ops pointing to dma-iommu operations after the domain becomes identity. Reaching the fault requires permission to change the IOMMU group type and rebind a PCI device; the next DMA allocation dereferences invalid state and produces a kernel oops.

The record

CVE
CVE-2021-47140
Published
Mar 25, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Mar 25, 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=08a27c1c3ecf5e1da193ce5f8fc97c3be16e75f0 <d6177a6556f853785867e2ec6d5b7f4906f0d809
  2. Affected versionversion=08a27c1c3ecf5e1da193ce5f8fc97c3be16e75f0 <f3f2cf46291a693eab21adb94171b0128c2a9ec1
  3. Affected versionversion=5.11

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=08a27c1c3ecf5e1da193ce5f8fc97c3be16e75f0 <d6177a6556f853785867e2ec6d5b7f4906f0d809; version=08a27c1c3ecf5e1da193ce5f8fc97c3be16e75f0 <f3f2cf46291a693eab21adb94171b0128c2a9ec1; version=5.11

Published CVSS scores

5.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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
Privilegesadmin
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

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Your stack

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