KVM: s390: Fix _gaccess_shadow_fault()

{
  "id": "8532e3bc99ad7f9680fe7ac397d1209ff0f1ae34d04d8e41a21aa7e4657ce0f3",
  "url": "https://osv.dev/vulnerability/CVE-2026-98653",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "KVM: s390: Fix _gaccess_shadow_fault()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Fix _gaccess_shadow_fault() In some circumstances, it is possible that the page of nested guest memory that is being shadowed is not present at all in the parent guest gmap. dat_entry_walk() will not find any leaf entry and return with -ENOENT, which will erroneously be propagated all the way to userspace. Fix by manually calling gmap_link() on the memory of the nested guest that is being shadowed if the mapping was not already present.",
    "evidence": "osv:CVE-2026-98653",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.2.9",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-98653",
      "aliases": [
        "CVE-2026-98653"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "e38c884df92119d96f652d51f82661dd2fc0b885"
                },
                {
                  "fixed": "94c43c7df46433ed4d1e18f13770b019ba977bd8"
                },
                {
                  "fixed": "faff4c8ff3dbec6d71b89dd281a0d17c4478fa44"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98653.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "7.0.0"
                },
                {
                  "fixed": "7.2.9"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98653.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:32.517302936Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/94c43c7df46433ed4d1e18f13770b019ba977bd8",
        "https://git.kernel.org/stable/c/faff4c8ff3dbec6d71b89dd281a0d17c4478fa44",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98653.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98653",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98653.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-98653",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 499695,
  "published_at": "2026-10-18T15:20:24.848+00:00"
}