CVE-2021-47471

Local kernel crash via null CRTC callback

Published May 22, 2024 · Updated May 11, 2026

NULL pointer dereference in the Linux kernel 5.10 mxsfb DRM driver allows local users to crash the system during driver unload. mxsfb_unload calls drm_irq_uninstall, which reaches mxsfb_irq_disable through crtc.funcs even when that function table is already NULL. Local low-privileged access and an active mxsfb device are required; the documented consequence is an availability loss with no data disclosure or modification.

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

NULL pointer dereference in the Linux kernel 5.10 mxsfb DRM driver allows local users to crash the system during driver unload. mxsfb_unload calls drm_irq_uninstall, which reaches mxsfb_irq_disable through crtc.funcs even when that function table is already NULL. Local low-privileged access and an active mxsfb device are required; the documented consequence is an availability loss with no data disclosure or modification.

The record

CVE
CVE-2021-47471
Published
May 22, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 22, 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=5.10
  2. Affected versionversion=ae1ed0093281939b80664a687689f12436c0e874 <3cfc183052c3dbf8eae57b6c1685dab00ed3db4a
  3. Affected versionversion=ae1ed0093281939b80664a687689f12436c0e874 <b0e6db0656ddfd8bb57303c2ef61ee1c1cc694a8
  4. Affected versionversion=ae1ed0093281939b80664a687689f12436c0e874 <f40c2281d2c0674d32ba732fee45222d76495472

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.10; version=ae1ed0093281939b80664a687689f12436c0e874 <3cfc183052c3dbf8eae57b6c1685dab00ed3db4a; version=ae1ed0093281939b80664a687689f12436c0e874 <b0e6db0656ddfd8bb57303c2ef61ee1c1cc694a8; version=ae1ed0093281939b80664a687689f12436c0e874 <f40c2281d2c0674d32ba732fee45222d76495472

Published CVSS scores

5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5CISA ADPCVSS: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-476NULL Pointer Dereference
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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