serial: core: fix NULL pointer dereference in serial_core_unregister_port()

{
  "id": "f1951e9a35d100e5acc605214d6d76b32ed9c00a6317df674c5b104f634986af",
  "url": "https://osv.dev/vulnerability/CVE-2026-98747",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "serial: core: fix NULL pointer dereference in serial_core_unregister_port()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: serial: core: fix NULL pointer dereference in serial_core_unregister_port() port->port_dev is NULL when no port device is installed: it is cleared on teardown, and never set if registration failed before serial_core_port_device_add(). serial_core_unregister_port() passes it straight to serial_core_get_ctrl_dev(), which dereferences it: KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047] RIP: serial_core_unregister_port Call Trace: serial8250_unregister_port serial8250_remove unbind_store Return early when there is no port device, and read port->port_dev under port_mutex. Also clear port->port_dev on the serial_core_register_port() error path, where the port device has already been removed.",
    "evidence": "osv:CVE-2026-98747",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.2.10",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-98747",
      "aliases": [
        "CVE-2026-98747"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "84a9582fd203063cd4d301204971ff2cd8327f1a"
                },
                {
                  "fixed": "54abbb862366dcaf1f22f1e968358147b7d0547d"
                },
                {
                  "fixed": "499485a67fbacf4d9afbdb43522388c64f853428"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98747.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.5.0"
                },
                {
                  "fixed": "7.2.10"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98747.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:42.901075228Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/499485a67fbacf4d9afbdb43522388c64f853428",
        "https://git.kernel.org/stable/c/54abbb862366dcaf1f22f1e968358147b7d0547d",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98747.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98747",
        "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-2026-98747.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-98747",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 510965,
  "published_at": "2026-10-18T15:47:32.607+00:00"
}