CVE-2026-98650

Full vulnerability record from the local CVENow database.

Description

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

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-18 16:17:18.290000

Last modified

2026-10-19 10:19:29.467000

View original CVE JSON

{
  "id": "CVE-2026-98650",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-18T16:17:18.290",
  "lastModified": "2026-10-19T10:19:29.467",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "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."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "arch/s390/kvm/gmap/dat.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "8e03e8316eb242af307d1c789d09f1a1457cf9a3",
              "lessThan": "c958f0498891203fddf2764b28f8b102c6bfd719",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "8e03e8316eb242af307d1c789d09f1a1457cf9a3",
              "lessThan": "27554b9505ddfc0aeab466aeb60929dfa17284c7",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "arch/s390/kvm/gmap/dat.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "7.0",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "7.0",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.9",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/27554b9505ddfc0aeab466aeb60929dfa17284c7",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c958f0498891203fddf2764b28f8b102c6bfd719",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}