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CVE-2026-80896 (GCVE-0-2026-80896)

Vulnerability from cvelistv5 – Published: 2026-09-04 17:11 – Updated: 2026-09-04 17:11
VLAI
Title
mshv: Fix race in mshv_irqfd_deassign
Summary
In the Linux kernel, the following vulnerability has been resolved: mshv: Fix race in mshv_irqfd_deassign mshv_irqfd_deactivate() and the hlist traversal of pt_irqfds_list require pt->pt_irqfds_lock to be held, but mshv_irqfd_deassign() omits it. This races with the EPOLLHUP path in mshv_irqfd_wakeup(), which does take the lock before calling mshv_irqfd_deactivate(). Additionally, mshv_irqfd_deactivate() uses hlist_del() which poisons the node pointers rather than resetting them. Since mshv_irqfd_is_active() relies on hlist_unhashed() (checks pprev == NULL), a poisoned node still appears active. If a concurrent path calls mshv_irqfd_deactivate() again on the same irqfd, the guard fails to prevent a double hlist_del() on poisoned pointers. Fix both issues: - Add the missing spin_lock_irq/spin_unlock_irq around the list traversal in mshv_irqfd_deassign(), matching mshv_irqfd_release(). - Use hlist_del_init() instead of hlist_del() so the node is properly marked as unhashed after removal, making the is_active guard reliable.
Severity
No CVSS data available.
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 621191d709b14882270dfd8ea5d7d6cdfebe2c35 , < 72a90ce4918b5a2d4820fe20677ba9af780d8826 (git)
Affected: 621191d709b14882270dfd8ea5d7d6cdfebe2c35 , < 4529a41a675b96e0f876eef1cc93a31a57cb4d18 (git)
Affected: 621191d709b14882270dfd8ea5d7d6cdfebe2c35 , < 0762262ac3e70f65b3bb843fe892f8bac1562d08 (git)
guessed Create a notification for this product.
Linux Linux Affected: 6.15
Unaffected: 0 , < 6.15 (semver)
Unaffected: 6.18.44 , ≤ 6.18.* (semver)
Unaffected: 7.1.8 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website

{
  "containers": {
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      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/hv/mshv_eventfd.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "versionType": "git"
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          "defaultStatus": "affected",
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          "vendor": "Linux",
          "versions": [
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              "status": "unaffected",
              "version": "7.1.8",
              "versionType": "semver"
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            {
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              "version": "7.2",
              "versionType": "original_commit_for_fix"
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      "cpeApplicability": [
        {
          "nodes": [
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                  "versionStartIncluding": "6.15",
                  "vulnerable": true
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                {
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                  "versionEndExcluding": "7.1.8",
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                  "versionStartIncluding": "6.15",
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                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmshv: Fix race in mshv_irqfd_deassign\n\nmshv_irqfd_deactivate() and the hlist traversal of pt_irqfds_list\nrequire pt-\u003ept_irqfds_lock to be held, but mshv_irqfd_deassign()\nomits it. This races with the EPOLLHUP path in mshv_irqfd_wakeup(),\nwhich does take the lock before calling mshv_irqfd_deactivate().\n\nAdditionally, mshv_irqfd_deactivate() uses hlist_del() which poisons\nthe node pointers rather than resetting them. Since\nmshv_irqfd_is_active() relies on hlist_unhashed() (checks pprev ==\nNULL), a poisoned node still appears active. If a concurrent path calls\nmshv_irqfd_deactivate() again on the same irqfd, the guard fails to\nprevent a double hlist_del() on poisoned pointers.\n\nFix both issues:\n- Add the missing spin_lock_irq/spin_unlock_irq around the list\n  traversal in mshv_irqfd_deassign(), matching mshv_irqfd_release().\n- Use hlist_del_init() instead of hlist_del() so the node is properly\n  marked as unhashed after removal, making the is_active guard reliable."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-04T17:11:11.689Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/72a90ce4918b5a2d4820fe20677ba9af780d8826"
        },
        {
          "url": "https://git.kernel.org/stable/c/4529a41a675b96e0f876eef1cc93a31a57cb4d18"
        },
        {
          "url": "https://git.kernel.org/stable/c/0762262ac3e70f65b3bb843fe892f8bac1562d08"
        }
      ],
      "title": "mshv: Fix race in mshv_irqfd_deassign",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80896",
    "datePublished": "2026-09-04T17:11:11.689Z",
    "dateReserved": "2026-08-26T14:34:25.800Z",
    "dateUpdated": "2026-09-04T17:11:11.689Z",
    "state": "PUBLISHED"
  },
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  "dataVersion": "5.2",
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    "nvd": "{\"cve\":{\"id\":\"CVE-2026-80896\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-09-04T18:17:57.847\",\"lastModified\":\"2026-09-04T18:17:57.847\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nmshv: Fix race in mshv_irqfd_deassign\\n\\nmshv_irqfd_deactivate() and the hlist traversal of pt_irqfds_list\\nrequire pt-\u003ept_irqfds_lock to be held, but mshv_irqfd_deassign()\\nomits it. This races with the EPOLLHUP path in mshv_irqfd_wakeup(),\\nwhich does take the lock before calling mshv_irqfd_deactivate().\\n\\nAdditionally, mshv_irqfd_deactivate() uses hlist_del() which poisons\\nthe node pointers rather than resetting them. Since\\nmshv_irqfd_is_active() relies on hlist_unhashed() (checks pprev ==\\nNULL), a poisoned node still appears active. If a concurrent path calls\\nmshv_irqfd_deactivate() again on the same irqfd, the guard fails to\\nprevent a double hlist_del() on poisoned pointers.\\n\\nFix both issues:\\n- Add the missing spin_lock_irq/spin_unlock_irq around the list\\n  traversal in mshv_irqfd_deassign(), matching mshv_irqfd_release().\\n- Use hlist_del_init() instead of hlist_del() so the node is properly\\n  marked as unhashed after removal, making the is_active guard reliable.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/hv/mshv_eventfd.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"621191d709b14882270dfd8ea5d7d6cdfebe2c35\",\"lessThan\":\"72a90ce4918b5a2d4820fe20677ba9af780d8826\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"621191d709b14882270dfd8ea5d7d6cdfebe2c35\",\"lessThan\":\"4529a41a675b96e0f876eef1cc93a31a57cb4d18\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"621191d709b14882270dfd8ea5d7d6cdfebe2c35\",\"lessThan\":\"0762262ac3e70f65b3bb843fe892f8bac1562d08\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/hv/mshv_eventfd.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.15\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.15\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.44\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.8\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/0762262ac3e70f65b3bb843fe892f8bac1562d08\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/4529a41a675b96e0f876eef1cc93a31a57cb4d18\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/72a90ce4918b5a2d4820fe20677ba9af780d8826\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "suse_vex": {
      "aggregate_severity": "not set",
      "current_release_date": "2026-09-05T00:25:01Z",
      "cve": "CVE-2026-80896",
      "id": "CVE-2026-80896",
      "initial_release_date": "2026-09-05T00:25:01Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-80896",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-80896.json",
      "version": "2"
    }
  }
}



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