CVE-2025-38442

Boot panic via unchecked oversized block size

Published Jul 25, 2025 · Updated May 11, 2026

NULL pointer dereference in Linux 6.15 allows local users to trigger a system panic during boot via an oversized-block device. Block-size validation permits the unsupported configuration, causing create_empty_buffers to proceed without the required large folio and dereference a null pointer. Reachability requires low-privileged local access, disabled THP, and a device whose logical block size exceeds the host page size; the consequence is an availability-only boot panic.

CVSS severity5.5
Medium
EPSS probability0.14%
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 Linux 6.15 allows local users to trigger a system panic during boot via an oversized-block device. Block-size validation permits the unsupported configuration, causing create_empty_buffers to proceed without the required large folio and dereference a null pointer. Reachability requires low-privileged local access, disabled THP, and a device whose logical block size exceeds the host page size; the consequence is an availability-only boot panic.

The record

CVE
CVE-2025-38442
Published
Jul 25, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 25, 2025CVE 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=47dd67532303803a87f43195e088b3b4bcf0454d <4cdf1bdd45ac78a088773722f009883af30ad318
  2. Affected versionversion=47dd67532303803a87f43195e088b3b4bcf0454d <b025d81b96bfe8a62b6e3e6ac776608206ccbf6d
  3. Affected versionversion=6.15

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=47dd67532303803a87f43195e088b3b4bcf0454d <4cdf1bdd45ac78a088773722f009883af30ad318; version=47dd67532303803a87f43195e088b3b4bcf0454d <b025d81b96bfe8a62b6e3e6ac776608206ccbf6d; version=6.15

Published CVSS scores

5.5CanonicalCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.7SUSECVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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-476NULL Pointer Dereference
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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