CVE-2021-47440

Kernel crash via unchecked regmap initialization error

Published May 22, 2024 · Updated May 11, 2026

NULL pointer dereference in the Linux ENCX24J600 Ethernet driver allows local users to crash the kernel during device probing. The encx24j600_spi_probe path passes an error pointer returned by devm_regmap_init_encx24j600 into later register access instead of checking it. Triggering the fault requires high-privileged local access to add or probe an SPI ENCX24J600 device and an initialization failure such as memory exhaustion; the demonstrated consequence is a kernel fault.

CVSS severity2.3
Low
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 ENCX24J600 Ethernet driver allows local users to crash the kernel during device probing. The encx24j600_spi_probe path passes an error pointer returned by devm_regmap_init_encx24j600 into later register access instead of checking it. Triggering the fault requires high-privileged local access to add or probe an SPI ENCX24J600 device and an initialization failure such as memory exhaustion; the demonstrated consequence is a kernel fault.

The record

CVE
CVE-2021-47440
Published
May 22, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
admin

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=04fbfce7a222327b97ca165294ef19f0faa45960 <322c0e53496309e634d9db7349678eaad1d25b55
  2. Affected versionversion=04fbfce7a222327b97ca165294ef19f0faa45960 <4c2eb80fc90b05559ce6ed1b8dfb2348420b5644
  3. Affected versionversion=04fbfce7a222327b97ca165294ef19f0faa45960 <5e5494e6fc8a29c927e0478bec4a078a40da8901
  4. Affected versionversion=04fbfce7a222327b97ca165294ef19f0faa45960 <66358471fa75a713fd76bc8a4bd74cb14cd50a4f
  5. Affected versionversion=04fbfce7a222327b97ca165294ef19f0faa45960 <e19c10d6e07c59c96e90fe053a72683ad8b0397e
  6. Affected versionversion=04fbfce7a222327b97ca165294ef19f0faa45960 <f03dca0c9e2297c84a018e306f8a9cd534ee4287
  7. Affected versionversion=04fbfce7a222327b97ca165294ef19f0faa45960 <f043fac1133a6c5ef960a8422c0f6dd711dee462
  8. Affected versionversion=04fbfce7a222327b97ca165294ef19f0faa45960 <fddc7f678d7fb93caa0d7bc512f968ff1e2bddbc
  9. Affected versionversion=4.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=04fbfce7a222327b97ca165294ef19f0faa45960 <322c0e53496309e634d9db7349678eaad1d25b55; version=04fbfce7a222327b97ca165294ef19f0faa45960 <4c2eb80fc90b05559ce6ed1b8dfb2348420b5644; version=04fbfce7a222327b97ca165294ef19f0faa45960 <5e5494e6fc8a29c927e0478bec4a078a40da8901; version=04fbfce7a222327b97ca165294ef19f0faa45960 <66358471fa75a713fd76bc8a4bd74cb14cd50a4f; version=04fbfce7a222327b97ca165294ef19f0faa45960 <e19c10d6e07c59c96e90fe053a72683ad8b0397e; version=04fbfce7a222327b97ca165294ef19f0faa45960 <f03dca0c9e2297c84a018e306f8a9cd534ee4287; version=04fbfce7a222327b97ca165294ef19f0faa45960 <f043fac1133a6c5ef960a8422c0f6dd711dee462; version=04fbfce7a222327b97ca165294ef19f0faa45960 <fddc7f678d7fb93caa0d7bc512f968ff1e2bddbc; version=4.4

Published CVSS scores

2.3CISA-ADPCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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
Privilegesadmin
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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