FKIE_CVE-2026-98546

Vulnerability from fkie_nvd - Published: 2026-10-18 16:17 - Updated: 2026-10-19 10:19
Severity
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.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/071f51188a5d8ec10535541255587976d12fc7d8
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2bc6b218717b9d08f466f88209251d54bc09b207
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/bb8c90c86441c090e9036f019cf1b4d7894a2c40
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ce71865bf43f88bed9d9218e9218e537150be506
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "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"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "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."
    }
  ],
  "id": "CVE-2026-98546",
  "lastModified": "2026-10-19T10:19:10.600",
  "metrics": {},
  "published": "2026-10-18T16:17:06.517",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/071f51188a5d8ec10535541255587976d12fc7d8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2bc6b218717b9d08f466f88209251d54bc09b207"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/bb8c90c86441c090e9036f019cf1b4d7894a2c40"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ce71865bf43f88bed9d9218e9218e537150be506"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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