CVE-2021-47531

Kernel crash via omitted mmap flags

Published May 24, 2024 · Updated May 11, 2026

Denial of service in Linux 5.15 through 5.15.6 allows local users to crash the kernel through msm DRM GEM memory mappings. The msm_gem_mmap_obj function bypasses DRM's default mmap path and fails to set VM_IO and VM_DONTDUMP on the VMA, allowing process_vm_readv during ARC++ logout to access an invalid kernel mapping. The demonstrated crash requires a Qualcomm msm GPU platform running ARC++ and a local low-privileged process, and it terminates the host kernel.

CVSS severity5.5
Medium
EPSS probability0.21%
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 Linux 5.15 through 5.15.6 allows local users to crash the kernel through msm DRM GEM memory mappings. The msm_gem_mmap_obj function bypasses DRM's default mmap path and fails to set VM_IO and VM_DONTDUMP on the VMA, allowing process_vm_readv during ARC++ logout to access an invalid kernel mapping. The demonstrated crash requires a Qualcomm msm GPU platform running ARC++ and a local low-privileged process, and it terminates the host kernel.

The record

CVE
CVE-2021-47531
Published
May 24, 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 24, 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=510410bfc034c57cc3caf1572aa47c1017bab2f9 <3466d9e217b337bf473ee629c608e53f9f3ab786
  2. Affected versionversion=510410bfc034c57cc3caf1572aa47c1017bab2f9 <8e2b7fe5e8a4be5e571561d9afcfbd92097288ba
  3. Affected versionversion=5.15

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=510410bfc034c57cc3caf1572aa47c1017bab2f9 <3466d9e217b337bf473ee629c608e53f9f3ab786; version=510410bfc034c57cc3caf1572aa47c1017bab2f9 <8e2b7fe5e8a4be5e571561d9afcfbd92097288ba; version=5.15

Published CVSS scores

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

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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