CVE-2025-40339

Kernel crash via null PRT buffer dereference

Published Dec 9, 2025 · Updated May 11, 2026

NULL-pointer dereference in the AMDGPU VM restore path in affected Linux kernels starting at 4.2 allows local users to crash the kernel. amdgpu_vm_handle_moved dereferences bo_va->base.bo for a PRT virtual-address mapping whose buffer object is always NULL because the KFD restore path fails to update that mapping separately first. Triggering the fault requires the AMDGPU KFD virtual-memory restore path and a PRT mapping; the resulting consequence is a kernel crash rather than data access.

CVSS severityUnavailable
Unscored
EPSS probability0.22%
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 AMDGPU VM restore path in affected Linux kernels starting at 4.2 allows local users to crash the kernel. amdgpu_vm_handle_moved dereferences bo_va->base.bo for a PRT virtual-address mapping whose buffer object is always NULL because the KFD restore path fails to update that mapping separately first. Triggering the fault requires the AMDGPU KFD virtual-memory restore path and a PRT mapping; the resulting consequence is a kernel crash rather than data access.

The record

CVE
CVE-2025-40339
Published
Dec 9, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Dec 9, 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=4.2
  2. Affected versionversion=d38ceaf99ed015f2a0b9af3499791bd3a3daae21 <273d1ea12e42e9babb9783837906f3c466f213d3
  3. Affected versionversion=d38ceaf99ed015f2a0b9af3499791bd3a3daae21 <47281febebe337586569aa4c5694a7511063a42e
  4. Affected versionversion=d38ceaf99ed015f2a0b9af3499791bd3a3daae21 <859958a7faefe5b7742b7b8cdbc170713d4bf158

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=4.2; version=d38ceaf99ed015f2a0b9af3499791bd3a3daae21 <273d1ea12e42e9babb9783837906f3c466f213d3; version=d38ceaf99ed015f2a0b9af3499791bd3a3daae21 <47281febebe337586569aa4c5694a7511063a42e; version=d38ceaf99ed015f2a0b9af3499791bd3a3daae21 <859958a7faefe5b7742b7b8cdbc170713d4bf158

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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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