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

Vulnerability from cvelistv5 – Published: 2026-10-18 15:20 – Updated: 2026-10-19 09:23
VLAI
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 6848 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 8e03e8316eb242af307d1c789d09f1a1457cf9a3 , < c958f0498891203fddf2764b28f8b102c6bfd719 (git)
Affected: 8e03e8316eb242af307d1c789d09f1a1457cf9a3 , < 27554b9505ddfc0aeab466aeb60929dfa17284c7 (git)
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Linux Linux Affected: 7.0
Unaffected: 0 , < 7.0 (semver)
Unaffected: 7.2.9 , ≤ 7.2.* (semver)
Unaffected: 7.3 , ≤ * (original_commit_for_fix)
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        }
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      "providerMetadata": {
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    "datePublished": "2026-10-18T15:20:22.173Z",
    "dateReserved": "2026-09-25T10:25:14.362Z",
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          {
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            "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."
          }
        ],
        "id": "CVE-2026-98650",
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        "metrics": {},
        "published": "2026-10-18T16:17:18.290",
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      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: KVM: s390: Fix potential races in dat skey functions",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98650.json",
      "version": "3"
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}



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