platform/x86: ISST: Validate socket ID in clos_assoc ioctl

{
  "id": "e08b4e6220a9f53cf3b76b95419ff7c8ae5d76b3725eb034231a082772961752",
  "url": "https://osv.dev/vulnerability/CVE-2026-89442",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "platform/x86: ISST: Validate socket ID in clos_assoc ioctl",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: platform/x86: ISST: Validate socket ID in clos_assoc ioctl isst_if_clos_assoc() validates the user-supplied socket_id with 'socket_id > topology_max_packages()', but isst_common.sst_inst[] is allocated with topology_max_packages() entries, so the valid index range is [0, topology_max_packages()). The '>' comparison lets socket_id == topology_max_packages() pass and index one entry past the array. In addition, isst_common.sst_inst[socket_id] is NULL for an in-range package that has no bound TPMI SST instance, and the pointer is used without a NULL check. Both the out-of-bounds entry and the NULL pointer are then dereferenced by map_partition_power_domain_id() and the following power_domain_info access. Reject socket_id >= topology_max_packages() and a NULL sst_inst, matching the checks already performed by get_instance().",
    "evidence": "osv:CVE-2026-89442",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.6.157",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.109",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.50",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.4",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-89442",
      "aliases": [
        "CVE-2026-89442"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "12a7d2cb811dd8a884dea088a2701fcb8d00136e"
                },
                {
                  "fixed": "c847ea4851ecfa3462cc711ded2c3c3dd8d08ab8"
                },
                {
                  "fixed": "0d90ab5f80e19cddfeb0c9fab47a1f34aa932075"
                },
                {
                  "fixed": "82e707eff9e3b7ef6d96ecc23ea8876d20c7d6ca"
                },
                {
                  "fixed": "207b4dc6eb100141b122b2602504a1429a4b6558"
                },
                {
                  "fixed": "a89f07db0cb95c54dac4a8406c79a04e44a73c3c"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89442.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.4.0"
                },
                {
                  "fixed": "6.6.157"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.109"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.50"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.4"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89442.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:41.947936626Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0d90ab5f80e19cddfeb0c9fab47a1f34aa932075",
        "https://git.kernel.org/stable/c/207b4dc6eb100141b122b2602504a1429a4b6558",
        "https://git.kernel.org/stable/c/82e707eff9e3b7ef6d96ecc23ea8876d20c7d6ca",
        "https://git.kernel.org/stable/c/a89f07db0cb95c54dac4a8406c79a04e44a73c3c",
        "https://git.kernel.org/stable/c/c847ea4851ecfa3462cc711ded2c3c3dd8d08ab8",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89442.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-89442",
        "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/2026/89xxx/CVE-2026-89442.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-89442",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 509681,
  "published_at": "2026-09-11T19:43:10.753+00:00"
}