Vulnerability-Lookup

GHSA-322J-R4FQ-PWX8

Vulnerability from github – Published: 2026-09-04 18:31 – Updated: 2026-09-04 18:31

Details

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.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-80896"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-04T18:17:57Z",
    "severity": null
  },
  "details": "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.",
  "id": "GHSA-322j-r4fq-pwx8",
  "modified": "2026-09-04T18:31:33Z",
  "published": "2026-09-04T18:31:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80896"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0762262ac3e70f65b3bb843fe892f8bac1562d08"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4529a41a675b96e0f876eef1cc93a31a57cb4d18"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/72a90ce4918b5a2d4820fe20677ba9af780d8826"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

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

Vulnerability from cvelistv5 – Published: 2026-09-04 17:11 – Updated: 2026-09-04 17:11

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.

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/72a90ce4918b5a2d4…
https://git.kernel.org/stable/c/4529a41a675b96e0f…
https://git.kernel.org/stable/c/0762262ac3e70f65b…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 621191d709b14882270dfd8ea5d7d6cdfebe2c35 , < 72a90ce4918b5a2d4820fe20677ba9af780d8826 (git) Affected: 621191d709b14882270dfd8ea5d7d6cdfebe2c35 , < 4529a41a675b96e0f876eef1cc93a31a57cb4d18 (git) Affected: 621191d709b14882270dfd8ea5d7d6cdfebe2c35 , < 0762262ac3e70f65b3bb843fe892f8bac1562d08 (git)
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)

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{
  "containers": {
    "cna": {
      "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": [
            {
              "lessThan": "72a90ce4918b5a2d4820fe20677ba9af780d8826",
              "status": "affected",
              "version": "621191d709b14882270dfd8ea5d7d6cdfebe2c35",
              "versionType": "git"
            },
            {
              "lessThan": "4529a41a675b96e0f876eef1cc93a31a57cb4d18",
              "status": "affected",
              "version": "621191d709b14882270dfd8ea5d7d6cdfebe2c35",
              "versionType": "git"
            },
            {
              "lessThan": "0762262ac3e70f65b3bb843fe892f8bac1562d08",
              "status": "affected",
              "version": "621191d709b14882270dfd8ea5d7d6cdfebe2c35",
              "versionType": "git"
            }
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          ],
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.15"
            },
            {
              "lessThan": "6.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
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          "nodes": [
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              "cpeMatch": [
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                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
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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"
      },
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        {
          "url": "https://git.kernel.org/stable/c/4529a41a675b96e0f876eef1cc93a31a57cb4d18"
        },
        {
          "url": "https://git.kernel.org/stable/c/0762262ac3e70f65b3bb843fe892f8bac1562d08"
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      ],
      "title": "mshv: Fix race in mshv_irqfd_deassign",
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        "engine": "bippy-1.2.0"
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    "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"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

GHSA-322J-R4FQ-PWX8

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

Tags

Sightings

Nomenclature