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GHSA-MMWF-2QGQ-F8XQ

Vulnerability from github – Published: 2026-10-18 18:31 – Updated: 2026-10-18 18:31

Details

In the Linux kernel, the following vulnerability has been resolved:

KVM: s390: Fix potential races in dat skey functions

When dat_cond_set_storage_key() finds a large page, it will conditionally set the storage key in absolute memory using large_crste_to_phys() to get the absolute address.

There is a race window between dat_entry_walk() and large_crste_to_phys(): the large page could have been split concurrently, and large_crste_to_phys() might be called with a crste that does not designate a large page, leading to crashes.

Similar issues were also present in dat_set_storage_key().

dat_get_storage_key() and dat_reset_reference_bit() did instead check for a potential concurrent splitting of the large page, but then handled it incorrectly.

Fix by performing a READ_ONCE on the crste pointer, checking and using the result, instead of dereferencing the pointer again. In case a race is detacted, try dat_entry_walk() again.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-98650"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-18T16:17:18Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: s390: Fix potential races in dat skey functions\n\nWhen dat_cond_set_storage_key() finds a large page, it will\nconditionally set the storage key in absolute memory using\nlarge_crste_to_phys() to get the absolute address.\n\nThere is a race window between dat_entry_walk() and\nlarge_crste_to_phys(): the large page could have been split\nconcurrently, and large_crste_to_phys() might be called with a crste\nthat does not designate a large page, leading to crashes.\n\nSimilar issues were also present in dat_set_storage_key().\n\ndat_get_storage_key() and dat_reset_reference_bit() did instead check\nfor a potential concurrent splitting of the large page, but then\nhandled it incorrectly.\n\nFix by performing a READ_ONCE on the crste pointer, checking and using\nthe result, instead of dereferencing the pointer again. In case a race\nis detacted, try dat_entry_walk() again.",
  "id": "GHSA-mmwf-2qgq-f8xq",
  "modified": "2026-10-18T18:31:58Z",
  "published": "2026-10-18T18:31:58Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98650"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/27554b9505ddfc0aeab466aeb60929dfa17284c7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c958f0498891203fddf2764b28f8b102c6bfd719"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-98650 (GCVE-0-2026-98650)

Vulnerability from cvelistv5 – Published: 2026-10-18 15:20 – Updated: 2026-10-19 09:23

Title

KVM: s390: Fix potential races in dat skey functions

Summary

In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Fix potential races in dat skey functions When dat_cond_set_storage_key() finds a large page, it will conditionally set the storage key in absolute memory using large_crste_to_phys() to get the absolute address. There is a race window between dat_entry_walk() and large_crste_to_phys(): the large page could have been split concurrently, and large_crste_to_phys() might be called with a crste that does not designate a large page, leading to crashes. Similar issues were also present in dat_set_storage_key(). dat_get_storage_key() and dat_reset_reference_bit() did instead check for a potential concurrent splitting of the large page, but then handled it incorrectly. Fix by performing a READ_ONCE on the crste pointer, checking and using the result, instead of dereferencing the pointer again. In case a race is detacted, try dat_entry_walk() again.

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6820 records in the last 180 days details

References

2 references

URL	Tags
https://git.kernel.org/stable/c/c958f0498891203fd…
https://git.kernel.org/stable/c/27554b9505ddfc0ae…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 8e03e8316eb242af307d1c789d09f1a1457cf9a3 , < c958f0498891203fddf2764b28f8b102c6bfd719 (git) Affected: 8e03e8316eb242af307d1c789d09f1a1457cf9a3 , < 27554b9505ddfc0aeab466aeb60929dfa17284c7 (git)
Linux	Linux	Affected: 7.0 Unaffected: 0 , < 7.0 (semver) Unaffected: 7.2.9 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

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        {
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          "programFiles": [
            "arch/s390/kvm/gmap/dat.c"
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          "vendor": "Linux",
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              "status": "affected",
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            },
            {
              "lessThan": "27554b9505ddfc0aeab466aeb60929dfa17284c7",
              "status": "affected",
              "version": "8e03e8316eb242af307d1c789d09f1a1457cf9a3",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
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          "versions": [
            {
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              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.9",
                  "versionStartIncluding": "7.0",
                  "vulnerable": true
                },
                {
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                }
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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: s390: Fix potential races in dat skey functions\n\nWhen dat_cond_set_storage_key() finds a large page, it will\nconditionally set the storage key in absolute memory using\nlarge_crste_to_phys() to get the absolute address.\n\nThere is a race window between dat_entry_walk() and\nlarge_crste_to_phys(): the large page could have been split\nconcurrently, and large_crste_to_phys() might be called with a crste\nthat does not designate a large page, leading to crashes.\n\nSimilar issues were also present in dat_set_storage_key().\n\ndat_get_storage_key() and dat_reset_reference_bit() did instead check\nfor a potential concurrent splitting of the large page, but then\nhandled it incorrectly.\n\nFix by performing a READ_ONCE on the crste pointer, checking and using\nthe result, instead of dereferencing the pointer again. In case a race\nis detacted, try dat_entry_walk() again."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:23:19.769Z",
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    "datePublished": "2026-10-18T15:20:22.173Z",
    "dateReserved": "2026-09-25T10:25:14.362Z",
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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.

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