{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2026-80895",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-80895",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-09-04T17:11:10.880Z",
    "updatedAt": "2026-09-04T17:11:10.880Z",
    "importedAt": "2026-10-24T01:58:30.346Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "mshv: Order pt_vp_array publish against irqfd assertion path",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nmshv: Order pt_vp_array publish against irqfd assertion path\n\nmshv_partition_ioctl_create_vp() initialises a VP struct (allocations,\nmutex_init, init_waitqueue_head, page mappings) and then publishes the\npointer into partition->pt_vp_array.  Several ISR paths read this array\nlocklessly: the intercept ISR, the two scheduler ISRs, and\nmshv_try_assert_irq_fast() on the irqfd fast path.\n\nOf these, only mshv_try_assert_irq_fast() can structurally race the\npublish.  It runs from an eventfd waker without holding pt_mutex, and\nMSHV_IRQFD does not require the target lapic_apic_id (== vp_index) to\nrefer to an existing VP at registration time.  A user can therefore\nregister an irqfd targeting a yet-to-be-created VP, then trigger\nmshv_try_assert_irq_fast() concurrently with MSHV_CREATE_VP for the\nsame index.  On weakly-ordered architectures the reader can observe a\nnon-NULL pointer in pt_vp_array before the initialising stores to the\nVP struct become visible, leading to use of partially-initialised\nfields (e.g. vp_register_page).\n\nThe other ISR readers cannot reach this race: the hypervisor will not\ngenerate intercept or scheduler messages for a VP that has never been\ntold to run, and the user can only call MSHV_RUN_VP on the VP fd\nreturned by MSHV_CREATE_VP, which by construction is returned after\nthe publish.  Leave those readers as plain loads.\n\nUse smp_store_release() in mshv_partition_ioctl_create_vp() to publish\nthe pointer, and pair it with smp_load_acquire() in\nmshv_try_assert_irq_fast().  On x86 these compile to plain accesses\nunder TSO; on ARM64 they emit one-instruction acquire/release barriers,\nacceptable on this fast path.\n\nThe destroy-side path (destroy_partition() clearing pt_vp_array[i] to\nNULL after kfree(vp)) has a separate ordering and lifetime concern\nthat is out of scope here.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "621191d709b14882270dfd8ea5d7d6cdfebe2c35",
              "status": "affected",
              "versionType": "git",
              "lessThan": "062aa5dcc49a9ad96726a80c2a0ab0a1233bc2b9"
            },
            {
              "version": "621191d709b14882270dfd8ea5d7d6cdfebe2c35",
              "status": "affected",
              "versionType": "git",
              "lessThan": "eba2bf5daa7933f94c53ebbbf0f567d4274716df"
            },
            {
              "version": "621191d709b14882270dfd8ea5d7d6cdfebe2c35",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b098dc869219c15dc49bf9cf63fb5fc1481d3373"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.15",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.15"
            },
            {
              "version": "6.18.44",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.1.8",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "version": "7.2",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}