CVE-2026-98546 (GCVE-0-2026-98546)
Vulnerability from cvelistv5
Published
2026-10-18 15:18
Modified
2026-10-19 09:21
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
Impacted products
Vendor Product Version
Linux Linux Version: 686d8f7b592f3466f44aea653c8147611b351c83
Version: 858c7bfcb35e1100b58bb63c9f562d86e09418d9
Version: 858c7bfcb35e1100b58bb63c9f562d86e09418d9
Version: 858c7bfcb35e1100b58bb63c9f562d86e09418d9
Version: 882f78400322c0aec4b641a7168adad9a66bc0c2
Version: 6.12.25   ≤
Version: 6.14.4   ≤
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{
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      "cpeApplicability": [
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      "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"
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          "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": {
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      }
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  "cveMetadata": {
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    "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"
}


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