Vulnerability-Lookup

GHSA-GFJH-3RR5-QGFR

Vulnerability from github – Published: 2026-10-18 18:31 – Updated: 2026-10-18 18:31

Details

In the Linux kernel, the following vulnerability has been resolved:

arm64/boot: Disable trapping of PMZR_EL0 writes to EL2

__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2. PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a write from EL0 reaches the trap and takes the host down without a panic message.

Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9 bits.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-98546"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-18T16:17:06Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64/boot: Disable trapping of PMZR_EL0 writes to EL2\n\n__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2.\nPMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in\nHDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host\ntraps to EL2, where the nVHE hypervisor has no handler and BUG()s. The\nkernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU\ndriver set PMUSERENR_EL0.UEN for a task with a user-read event, so a\nwrite from EL0 reaches the trap and takes the host down without a panic\nmessage.\n\nAccumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already\ndoes for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9\nbits.",
  "id": "GHSA-gfjh-3rr5-qgfr",
  "modified": "2026-10-18T18:31:53Z",
  "published": "2026-10-18T18:31:53Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98546"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/071f51188a5d8ec10535541255587976d12fc7d8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2bc6b218717b9d08f466f88209251d54bc09b207"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bb8c90c86441c090e9036f019cf1b4d7894a2c40"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ce71865bf43f88bed9d9218e9218e537150be506"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-98546 (GCVE-0-2026-98546)

Vulnerability from cvelistv5 – Published: 2026-10-18 15:18 – Updated: 2026-10-19 09:21

Title

arm64/boot: Disable trapping of PMZR_EL0 writes to EL2

Summary

In the Linux kernel, the following vulnerability has been resolved: arm64/boot: Disable trapping of PMZR_EL0 writes to EL2 __init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2. PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a write from EL0 reaches the trap and takes the host down without a panic message. Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9 bits.

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 7018 records in the last 180 days details

References

4 references

URL	Tags
https://git.kernel.org/stable/c/bb8c90c86441c090e…
https://git.kernel.org/stable/c/071f51188a5d8ec10…
https://git.kernel.org/stable/c/ce71865bf43f88bed…
https://git.kernel.org/stable/c/2bc6b218717b9d08f…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 686d8f7b592f3466f44aea653c8147611b351c83 , < bb8c90c86441c090e9036f019cf1b4d7894a2c40 (git) Affected: 858c7bfcb35e1100b58bb63c9f562d86e09418d9 , < 071f51188a5d8ec10535541255587976d12fc7d8 (git) Affected: 858c7bfcb35e1100b58bb63c9f562d86e09418d9 , < ce71865bf43f88bed9d9218e9218e537150be506 (git) Affected: 858c7bfcb35e1100b58bb63c9f562d86e09418d9 , < 2bc6b218717b9d08f466f88209251d54bc09b207 (git) Affected: 882f78400322c0aec4b641a7168adad9a66bc0c2 (git) Affected: 6.12.25 , < 6.12.112 (semver) Affected: 6.14.4 , < 6.15 (semver)
Linux	Linux	Affected: 6.15 Unaffected: 0 , < 6.15 (semver) Unaffected: 6.12.112 , ≤ 6.12.* (semver) Unaffected: 6.18.55 , ≤ 6.18.* (semver) Unaffected: 7.2.9 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "Documentation/arch/arm64/booting.rst",
            "arch/arm64/include/asm/el2_setup.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "bb8c90c86441c090e9036f019cf1b4d7894a2c40",
              "status": "affected",
              "version": "686d8f7b592f3466f44aea653c8147611b351c83",
              "versionType": "git"
            },
            {
              "lessThan": "071f51188a5d8ec10535541255587976d12fc7d8",
              "status": "affected",
              "version": "858c7bfcb35e1100b58bb63c9f562d86e09418d9",
              "versionType": "git"
            },
            {
              "lessThan": "ce71865bf43f88bed9d9218e9218e537150be506",
              "status": "affected",
              "version": "858c7bfcb35e1100b58bb63c9f562d86e09418d9",
              "versionType": "git"
            },
            {
              "lessThan": "2bc6b218717b9d08f466f88209251d54bc09b207",
              "status": "affected",
              "version": "858c7bfcb35e1100b58bb63c9f562d86e09418d9",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "882f78400322c0aec4b641a7168adad9a66bc0c2",
              "versionType": "git"
            },
            {
              "lessThan": "6.12.112",
              "status": "affected",
              "version": "6.12.25",
              "versionType": "semver"
            },
            {
              "lessThan": "6.15",
              "status": "affected",
              "version": "6.14.4",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "Documentation/arch/arm64/booting.rst",
            "arch/arm64/include/asm/el2_setup.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.15"
            },
            {
              "lessThan": "6.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.112",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.55",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.112",
                  "versionStartIncluding": "6.12.25",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.55",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.9",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.14.4",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64/boot: Disable trapping of PMZR_EL0 writes to EL2\n\n__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2.\nPMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in\nHDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host\ntraps to EL2, where the nVHE hypervisor has no handler and BUG()s. The\nkernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU\ndriver set PMUSERENR_EL0.UEN for a task with a user-read event, so a\nwrite from EL0 reaches the trap and takes the host down without a panic\nmessage.\n\nAccumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already\ndoes for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9\nbits."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:21:29.442Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/bb8c90c86441c090e9036f019cf1b4d7894a2c40"
        },
        {
          "url": "https://git.kernel.org/stable/c/071f51188a5d8ec10535541255587976d12fc7d8"
        },
        {
          "url": "https://git.kernel.org/stable/c/ce71865bf43f88bed9d9218e9218e537150be506"
        },
        {
          "url": "https://git.kernel.org/stable/c/2bc6b218717b9d08f466f88209251d54bc09b207"
        }
      ],
      "title": "arm64/boot: Disable trapping of PMZR_EL0 writes to EL2",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98546",
    "datePublished": "2026-10-18T15:18:14.808Z",
    "dateReserved": "2026-09-25T10:25:14.356Z",
    "dateUpdated": "2026-10-19T09:21:29.442Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted