← Back to CVE Explorer

CVE-2026-31568

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: s390/mm: Add missing secure storage access fixups for donated memory There are special cases where secure storage access exceptions happen in a kernel context for pages that don't have the PG_arch_1 bit set. That bit is set for non-exported guest secure storage (memory) but is absent on storage donated to the Ultravisor since the kernel isn't allowed to export donated pages. Prior to this patch we would try to export the page by calling arch_make_folio_accessible() which would instantly return since the arch bit is absent signifying that the page was already exported and no further action is necessary. This leads to secure storage access exception loops which can never be resolved. With this patch we unconditionally try to export and if that fails we fixup.

Severity
HIGH
CVSS score
7.1 (v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-04-24 15:16:31.313000
Last modified
2026-10-30 13:18:41.130000
View original CVE JSON 
{
  "id": "CVE-2026-31568",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-04-24T15:16:31.313",
  "lastModified": "2026-10-30T13:18:41.130",
  "vulnStatus": "Modified",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/mm: Add missing secure storage access fixups for donated memory\n\nThere are special cases where secure storage access exceptions happen\nin a kernel context for pages that don't have the PG_arch_1 bit\nset. That bit is set for non-exported guest secure storage (memory)\nbut is absent on storage donated to the Ultravisor since the kernel\nisn't allowed to export donated pages.\n\nPrior to this patch we would try to export the page by calling\narch_make_folio_accessible() which would instantly return since the\narch bit is absent signifying that the page was already exported and\nno further action is necessary. This leads to secure storage access\nexception loops which can never be resolved.\n\nWith this patch we unconditionally try to export and if that fails we\nfixup."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "arch/s390/mm/fault.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "084ea4d611a3d00ee3930400b262240e10895900",
              "lessThan": "48eda93e50f8361dee8e261fe55d0b31714e1e56",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "084ea4d611a3d00ee3930400b262240e10895900",
              "lessThan": "1eb35c54cd81cf874ce7d69e3dbfb162f211b8bd",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "084ea4d611a3d00ee3930400b262240e10895900",
              "lessThan": "b36b0e804aee5f20c6798dbeaeaa7cfdb7c6cf88",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "084ea4d611a3d00ee3930400b262240e10895900",
              "lessThan": "43ac2d18db1131df0a89993f709131ebfc29f3bd",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "084ea4d611a3d00ee3930400b262240e10895900",
              "lessThan": "b00be77302d7ec4ad0367bb236494fce7172b730",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "arch/s390/mm/fault.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5.7",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "5.7",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.160",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.21",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.19.11",
              "lessThanOrEqual": "6.19.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.0",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.2
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "5.7.1",
              "versionEndExcluding": "6.18.21",
              "matchCriteriaId": "E034C3DB-8767-405F-B61D-0462FF99F64E"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.19",
              "versionEndExcluding": "6.19.11",
              "matchCriteriaId": "4CA2E747-A9EC-4518-9AA2-B4247FC748B7"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.7:-:*:*:*:*:*:*",
              "matchCriteriaId": "3D23CE42-BDB2-4216-8495-230ABE98FCDD"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*",
              "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*",
              "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*",
              "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*",
              "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*",
              "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*",
              "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1eb35c54cd81cf874ce7d69e3dbfb162f211b8bd",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/43ac2d18db1131df0a89993f709131ebfc29f3bd",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/48eda93e50f8361dee8e261fe55d0b31714e1e56",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b00be77302d7ec4ad0367bb236494fce7172b730",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/b36b0e804aee5f20c6798dbeaeaa7cfdb7c6cf88",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    }
  ]
}