CVE-2023-54240

Kernel crash via unchecked rule count

Published Dec 30, 2025 · Updated Dec 30, 2025

NULL pointer dereference in the Linux MediaTek Ethernet driver allows local users to crash the kernel via a crafted ethtool request. The mtk_hwlro_get_fdir_all() path uses rule_locs without first checking the user-controlled rule_cnt that determines its allocation size, so a zero count can leave the pointer NULL. Reaching the flaw requires local access to issue the affected receive-flow-classification operation on a MediaTek Ethernet interface; the bounded consequence is a kernel crash and service interruption.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

NULL pointer dereference in the Linux MediaTek Ethernet driver allows local users to crash the kernel via a crafted ethtool request. The mtk_hwlro_get_fdir_all() path uses rule_locs without first checking the user-controlled rule_cnt that determines its allocation size, so a zero count can leave the pointer NULL. Reaching the flaw requires local access to issue the affected receive-flow-classification operation on a MediaTek Ethernet interface; the bounded consequence is a kernel crash and service interruption.

The record

CVE
CVE-2023-54240
Published
Dec 30, 2025
Updated
Dec 30, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 30, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 30, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.9
  2. Affected versionversion=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <072324cfab9b96071c0782f51f53cc5aea1e9d5b
  3. Affected versionversion=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <653fbddbdfc6673bba01b13dae5a4384ad8f92ec
  4. Affected versionversion=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <751b2e22a188b0c306029d094da29b6b8de31430
  5. Affected versionversion=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <75f2de75c1182e80708c932418e4895dbc88b68f
  6. Affected versionversion=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <7776591e5ae2befff86579f68916a171971c6aab
  7. Affected versionversion=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <e4c79810755f66c9a933ca810da2724133b1165a
  8. Affected versionversion=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <fe0195fe48f85182bc7e7eabcad925bd3cbc10f5
  9. Affected versionversion=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <ff5faed5f5487b0fd2b640ba1304f82a5ebaab42

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.9; version=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <072324cfab9b96071c0782f51f53cc5aea1e9d5b; version=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <653fbddbdfc6673bba01b13dae5a4384ad8f92ec; version=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <751b2e22a188b0c306029d094da29b6b8de31430; version=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <75f2de75c1182e80708c932418e4895dbc88b68f; version=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <7776591e5ae2befff86579f68916a171971c6aab; version=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <e4c79810755f66c9a933ca810da2724133b1165a; version=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <fe0195fe48f85182bc7e7eabcad925bd3cbc10f5; version=7aab747e5563ecbc9f3cb64ddea13fe7b9fee2bd <ff5faed5f5487b0fd2b640ba1304f82a5ebaab42

Published CVSS scores

No CVSS assessment is available in this record.

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

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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