powerpc/kexec_file: Fix null-ptr-def in extra size calculation

{
  "id": "5d97da3368993a020844a0b52769c1678bcd30d2097b77595a205d1e188680be",
  "url": "https://osv.dev/vulnerability/CVE-2026-89963",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "powerpc/kexec_file: Fix null-ptr-def in extra size calculation",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: powerpc/kexec_file: Fix null-ptr-def in extra size calculation A static Sashiko AI review identified a potential NULL pointer dereference in kexec_extra_fdt_size_ppc64(). On platforms without any reserved memory regions, get_reserved_memory_ranges() can return 0 while leaving 'rmem' unallocated as NULL. Passing it directly leads to a kernel panic when evaluating 'rmem->nr_ranges'. Add a NULL check for 'rmem' to prevent this crash.",
    "evidence": "osv:CVE-2026-89963",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.110",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.51",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.5",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-89963",
      "aliases": [
        "CVE-2026-89963"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0d3ff067331ef84e7e7f49537d768881042ed5ba"
                },
                {
                  "fixed": "11ef1c2a5dbe0bd8c1345f59bab7331d352f02cf"
                },
                {
                  "fixed": "df45337587db21c502fe5251d3bcc7887428f4fb"
                },
                {
                  "fixed": "4ff3d9fd71c7bc2fc81afdac1970d9c55a5c0dea"
                },
                {
                  "fixed": "761eda315a6e1fda3e8e2185b28430771fb1ac29"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89963.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.11.0"
                },
                {
                  "fixed": "6.12.110"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.51"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.5"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89963.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:37.299138579Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/11ef1c2a5dbe0bd8c1345f59bab7331d352f02cf",
        "https://git.kernel.org/stable/c/4ff3d9fd71c7bc2fc81afdac1970d9c55a5c0dea",
        "https://git.kernel.org/stable/c/761eda315a6e1fda3e8e2185b28430771fb1ac29",
        "https://git.kernel.org/stable/c/df45337587db21c502fe5251d3bcc7887428f4fb",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89963.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-89963",
        "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-2026-89963.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-89963",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 504832,
  "published_at": "2026-09-16T10:32:45.336+00:00"
}