FKIE_CVE-2026-93239

Vulnerability from fkie_nvd - Published: 2026-09-24 16:17 - Updated: 2026-09-24 16:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: arm64: mm: Fix the lockless page-table walk in show_pte() show_pte() walks page tables locklessly and can run with interrupts enabled. A concurrent teardown can free a table page while it is being walked. It can also clear a parent entry after show_pte() checked it; the regular pXd_offset() helpers then reread the cleared entry and can derive a bogus lower-level pointer and fault again. Use the lockless offset helpers with the saved parent entries, as gup_fast() does, and pass the saved PMD to pte_offset_map(). For task page tables, arm64 selects MMU_GATHER_RCU_TABLE_FREE. Disable local interrupts around the walk to hold off RCU-deferred table frees and block the tlb_remove_table_sync_one() IPI until the walk is finished. Place the IRQ guard after the header print. This does not make the output a consistent snapshot, but prevents the task page-table walk from dereferencing a released table page or deriving a pointer from a different parent value.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/08d931a0a850ad16a64f2cd23a19f40795cdbdf7
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0f05d95b99164a9ccc4cf4a4920e0ff0228138ad
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/68cbd70795dd8c06e7ccdc4eb0b74c5b180076c3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a77644d009dece1104b6fcc6e322b0e4503db0d6
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b28fe65a36b8209b6adcf2722c7ce974cf9ac8d1
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/mm/fault.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "08d931a0a850ad16a64f2cd23a19f40795cdbdf7",
              "status": "affected",
              "version": "1d18c47c735e8adfe531fc41fae31e98f86b68fe",
              "versionType": "git"
            },
            {
              "lessThan": "b28fe65a36b8209b6adcf2722c7ce974cf9ac8d1",
              "status": "affected",
              "version": "1d18c47c735e8adfe531fc41fae31e98f86b68fe",
              "versionType": "git"
            },
            {
              "lessThan": "68cbd70795dd8c06e7ccdc4eb0b74c5b180076c3",
              "status": "affected",
              "version": "1d18c47c735e8adfe531fc41fae31e98f86b68fe",
              "versionType": "git"
            },
            {
              "lessThan": "0f05d95b99164a9ccc4cf4a4920e0ff0228138ad",
              "status": "affected",
              "version": "1d18c47c735e8adfe531fc41fae31e98f86b68fe",
              "versionType": "git"
            },
            {
              "lessThan": "a77644d009dece1104b6fcc6e322b0e4503db0d6",
              "status": "affected",
              "version": "1d18c47c735e8adfe531fc41fae31e98f86b68fe",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/mm/fault.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.7"
            },
            {
              "lessThan": "3.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.110",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.51",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc2",
              "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: mm: Fix the lockless page-table walk in show_pte()\n\nshow_pte() walks page tables locklessly and can run with interrupts\nenabled. A concurrent teardown can free a table page while it is being\nwalked. It can also clear a parent entry after show_pte() checked it; the\nregular pXd_offset() helpers then reread the cleared entry and can derive a\nbogus lower-level pointer and fault again.\n\nUse the lockless offset helpers with the saved parent entries, as\ngup_fast() does, and pass the saved PMD to pte_offset_map().\n\nFor task page tables, arm64 selects MMU_GATHER_RCU_TABLE_FREE. Disable\nlocal interrupts around the walk to hold off RCU-deferred table frees and\nblock the tlb_remove_table_sync_one() IPI until the walk is finished.\n\nPlace the IRQ guard after the header print. This does not make the output a\nconsistent snapshot, but prevents the task page-table walk from\ndereferencing a released table page or deriving a pointer from a different\nparent value."
    }
  ],
  "id": "CVE-2026-93239",
  "lastModified": "2026-09-24T16:17:19.690",
  "metrics": {},
  "published": "2026-09-24T16:17:19.690",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/08d931a0a850ad16a64f2cd23a19f40795cdbdf7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0f05d95b99164a9ccc4cf4a4920e0ff0228138ad"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/68cbd70795dd8c06e7ccdc4eb0b74c5b180076c3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a77644d009dece1104b6fcc6e322b0e4503db0d6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b28fe65a36b8209b6adcf2722c7ce974cf9ac8d1"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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