CVE-2025-21842

Kernel crash via incorrect GTT pointer free

Published Mar 7, 2025 · Updated Aug 5, 2026

Incorrect pointer handling in Linux kernel amdkfd allows local users to crash the kernel through a crafted queue-creation request. In kfd_process_queue_manager.c, the queue-init failure path passes gang_ctx_bo as void * to amdgpu_amdkfd_free_gtt_mem(), which dereferences it as void **. A local user with render-group access to /dev/kfd can trigger the path; the invalid dereference causes an oops or panic on SMAP-enabled systems and permits kernel-memory corruption when the fixed address is user-mapped on systems without SMAP or PAN.

CVSS severity7.8
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect pointer handling in Linux kernel amdkfd allows local users to crash the kernel through a crafted queue-creation request. In kfd_process_queue_manager.c, the queue-init failure path passes gang_ctx_bo as void * to amdgpu_amdkfd_free_gtt_mem(), which dereferences it as void **. A local user with render-group access to /dev/kfd can trigger the path; the invalid dereference causes an oops or panic on SMAP-enabled systems and permits kernel-memory corruption when the fixed address is user-mapped on systems without SMAP or PAN.

The record

CVE
CVE-2025-21842
Published
Mar 7, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 7, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=6.12
  2. Affected versionversion=fb91065851cd5f2735348c5f3eddeeca3d7c2973 <091a68c58c1bbd2ab7d05d1b32c1306394ec691d
  3. Affected versionversion=fb91065851cd5f2735348c5f3eddeeca3d7c2973 <a33f7f9660705fb2ecf3467b2c48965564f392ce
  4. Affected versionversion=fb91065851cd5f2735348c5f3eddeeca3d7c2973 <ae5ab1c1ae504f622cc1ff48830a9ed48428146d

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.12; version=fb91065851cd5f2735348c5f3eddeeca3d7c2973 <091a68c58c1bbd2ab7d05d1b32c1306394ec691d; version=fb91065851cd5f2735348c5f3eddeeca3d7c2973 <a33f7f9660705fb2ecf3467b2c48965564f392ce; version=fb91065851cd5f2735348c5f3eddeeca3d7c2973 <ae5ab1c1ae504f622cc1ff48830a9ed48428146d

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8Linux kernel CNACVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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

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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