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arm64: mm: Handle invalid large leaf mappings correctly

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: arm64: mm: Handle invalid large leaf mappings correctly It has been possible for a long time to mark ptes in the linear map as invalid. This is done for secretmem, kfence, realm dma memory un/share, and others, by simply clearing the PTE_VALID bit. But until commit a166563e7ec37 ("arm64: mm: support large block mapping when rodata=full") large leaf mappings were never made invalid in this way. It turns out various parts of the code base are not equipped to handle invalid large leaf mappings (in the way they are currently encoded) and I've observed a kernel panic while booting a realm guest on a BBML2_NOABORT system as a result: [ 15.432706] software IO TLB: Memory encryption is active and system is using DMA bounce buffers [ 15.476896] Unable to handle kernel paging request at virtual address ffff000019600000 [ 15.513762] Mem abort info: [ 15.527245] ESR = 0x0000000096000046 [ 15.548553] EC = 0x25: DABT (current EL), IL = 32 bits [ 15.572146] SET = 0, FnV = 0 [ 15.592141] EA = 0, S1PTW = 0 [ 15.612694] FSC = 0x06: level 2 translation fault [ 15.640644] Data abort info: [ 15.661983] ISV = 0, ISS = 0x00000046, ISS2 = 0x00000000 [ 15.694875] CM = 0, WnR = 1, TnD = 0, TagAccess = 0 [ 15.723740] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 15.755776] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000081f3f000 [ 15.800410] [ffff000019600000] pgd=0000000000000000, p4d=180000009ffff403, pud=180000009fffe403, pmd=00e

Announced Source revision 1
Original source ↗

CVE-2026-31600

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-31600

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
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Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "a166563e7ec375b38a0fd3a58f7b77e50a6bc6a8",
        "lessThan": "8140b21d19015227a28c255404462f2d3e6edc9a",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "a166563e7ec375b38a0fd3a58f7b77e50a6bc6a8",
        "lessThan": "747b6482e4e227fd351197dde6f64a97107a9e52",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "a166563e7ec375b38a0fd3a58f7b77e50a6bc6a8",
        "lessThan": "cbea627ea634f41c79d18f0c6d20db66fa93514c",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "a166563e7ec375b38a0fd3a58f7b77e50a6bc6a8",
        "lessThan": "15bfba1ad77fad8e45a37aae54b3c813b33fe27c",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "arch/arm64/include/asm/pgtable-prot.h",
      "arch/arm64/include/asm/pgtable.h",
      "arch/arm64/mm/mmu.c",
      "arch/arm64/mm/pageattr.c",
      "arch/arm64/mm/trans_pgd.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "6.18"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "6.18",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.18.24",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "6.19.14",
        "versionType": "semver",
        "lessThanOrEqual": "6.19.*"
      },
      {
        "status": "unaffected",
        "version": "7.0.1",
        "versionType": "semver",
        "lessThanOrEqual": "7.0.*"
      },
      {
        "status": "unaffected",
        "version": "7.1",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "arch/arm64/include/asm/pgtable-prot.h",
      "arch/arm64/include/asm/pgtable.h",
      "arch/arm64/mm/mmu.c",
      "arch/arm64/mm/pageattr.c",
      "arch/arm64/mm/trans_pgd.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-31600

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#39928 · Revision 1
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Publisher date
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