CVE-2021-4148

Local kernel crash via huge-page invalidation

Published Mar 23, 2022 · Updated Aug 3, 2024

Improper page invalidation in the Linux kernel before 5.14.16 allows local users to crash the kernel through a huge-page operation. block_invalidatepage compares a huge-page-sized invalidation length against PAGE_SIZE and invokes the BUG assertion when the length exceeds one base page. A local user must reach the read-only filesystem transparent-huge-page path; triggering the assertion terminates the running kernel and interrupts the host.

CVSS severity5.5
Medium
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper page invalidation in the Linux kernel before 5.14.16 allows local users to crash the kernel through a huge-page operation. block_invalidatepage compares a huge-page-sized invalidation length against PAGE_SIZE and invokes the BUG assertion when the length exceeds one base page. A local user must reach the read-only filesystem transparent-huge-page path; triggering the assertion terminates the running kernel and interrupts the host.

The record

CVE
CVE-2021-4148
Published
Mar 23, 2022
Updated
Aug 3, 2024
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-354, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 23, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record 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=kernel 5.14.16

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=kernel 5.14.16

Published CVSS scores

4.9NIST NVDAV:L/AC:L/Au:N/C:N/I:N/A:C
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.

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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-354Improper Validation of Integrity Check Value
T1499.004Application or System Exploitation

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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