CVE-2026-74600 (GCVE-0-2026-74600)

Vulnerability from cvelistv5 – Published: 2026-08-22 15:31 – Updated: 2026-08-23 12:47
VLAI
Title
mm/page_table_check: skip special zero mappings
Summary
In the Linux kernel, the following vulnerability has been resolved: mm/page_table_check: skip special zero mappings page_table_check_set() and page_table_check_clear() account mappings based on PageAnon(). Shared zero-page PTEs and huge zero PMDs are special mappings, but page_table_check can still account them as file-backed pages. An unprivileged process can populate enough zero mappings to overflow file_map_count and hit the existing BUG_ON(). The PTE path can do this with the shared zero page, and the PMD path can do the same with huge zero mappings. Skip special zero mappings in the user page-table accounting paths. Keep the PTE-side pte_special() check, and identify huge zero PMDs from the mapped folio instead of pmd_special(). That covers architectures where pmd_special() is a no-op without adding huge_zero_pfn checks to the generic counter helpers.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: df4e817b710809425d899340dbfa8504a3ca4ba5 , < 7755be923e325dc300f4b0c3e1ad7e91b28b3cb9 (git)
Affected: df4e817b710809425d899340dbfa8504a3ca4ba5 , < b726eb3c94d23e09da0e0f46b0fa09fb2b5d99cc (git)
Affected: df4e817b710809425d899340dbfa8504a3ca4ba5 , < 8db4bab826ccc9ec10fa41736a48031cd338d392 (git)
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Linux Linux Affected: 5.17
Unaffected: 0 , < 5.17 (semver)
Unaffected: 6.18.46 , ≤ 6.18.* (semver)
Unaffected: 7.1.9 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
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        {
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          "product": "Linux",
          "programFiles": [
            "mm/page_table_check.c"
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              "negate": false,
              "operator": "OR"
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_table_check: skip special zero mappings\n\npage_table_check_set() and page_table_check_clear() account mappings based\non PageAnon().  Shared zero-page PTEs and huge zero PMDs are special\nmappings, but page_table_check can still account them as file-backed\npages.\n\nAn unprivileged process can populate enough zero mappings to overflow\nfile_map_count and hit the existing BUG_ON().  The PTE path can do this\nwith the shared zero page, and the PMD path can do the same with huge zero\nmappings.\n\nSkip special zero mappings in the user page-table accounting paths.  Keep\nthe PTE-side pte_special() check, and identify huge zero PMDs from the\nmapped folio instead of pmd_special().  That covers architectures where\npmd_special() is a no-op without adding huge_zero_pfn checks to the\ngeneric counter helpers."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-23T12:47:40.893Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/7755be923e325dc300f4b0c3e1ad7e91b28b3cb9"
        },
        {
          "url": "https://git.kernel.org/stable/c/b726eb3c94d23e09da0e0f46b0fa09fb2b5d99cc"
        },
        {
          "url": "https://git.kernel.org/stable/c/8db4bab826ccc9ec10fa41736a48031cd338d392"
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      ],
      "title": "mm/page_table_check: skip special zero mappings",
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74600",
    "datePublished": "2026-08-22T15:31:49.334Z",
    "dateReserved": "2026-08-15T05:44:03.919Z",
    "dateUpdated": "2026-08-23T12:47:40.893Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
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      "date": "2026-09-01",
      "epss": "0.00166",
      "percentile": "0.0612"
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      "cve": "CVE-2026-74600",
      "id": "msrc_CVE-2026-74600",
      "initial_release_date": "2026-08-24T01:03:55.000Z",
      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "mm/page_table_check: skip special zero mappings",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-74600.json",
      "version": "2"
    },
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    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-24T13:30:40+00:00",
      "cve": "CVE-2026-74600",
      "id": "CVE-2026-74600",
      "initial_release_date": "2026-08-22T00:00:00+00:00",
      "product_status:known_affected": "76",
      "product_status:known_not_affected": "198",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: mm/page_table_check: skip special zero mappings",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74600.json",
      "version": "3"
    }
  }
}



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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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