nfsd: widen nfsd_genl_rqstp address fields to sockaddr_storage

{
  "id": "559ae21ec1abc7db0e1144ef9840d2f0c592167c4a4d58c51660313ae01d1c18",
  "url": "https://osv.dev/vulnerability/CVE-2026-89698",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "nfsd: widen nfsd_genl_rqstp address fields to sockaddr_storage",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: nfsd: widen nfsd_genl_rqstp address fields to sockaddr_storage struct nfsd_genl_rqstp declares rq_daddr and rq_saddr as plain \"struct sockaddr\" (16 bytes). When an IPv6 NFS client is connected, nfsd_genl_rpc_status_compose_msg() casts these fields to \"struct sockaddr_in6 *\" (28 bytes) and reads sin6_addr at offset 8..24, which extends 8 bytes past the end of the 16-byte sockaddr field into the adjacent rq_flags member. The 16-byte nla_put_in6_addr then ships 8 bytes of truncated IPv6 address followed by 8 bytes of rq_flags to userspace via the NFSD_A_RPC_STATUS_SADDR6/DADDR6 netlink attributes. This is reachable by any unprivileged process in the network namespace because NFSD_CMD_RPC_STATUS_GET uses GENL_CMD_CAP_DUMP without GENL_ADMIN_PERM. Fix by widening rq_daddr and rq_saddr to struct sockaddr_storage so the IPv6 casts operate within bounds, copying sizeof(struct sockaddr_storage) bytes in the memcpy calls so the full address is captured, and zero-initializing the genl_rqstp stack variable to prevent leaking uninitialized tail bytes through netlink.",
    "evidence": "osv:CVE-2026-89698",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.111",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.51",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.4",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-89698",
      "aliases": [
        "CVE-2026-89698"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "bd9d6a3efa9709e653aafbeb859289feccb8e70c"
                },
                {
                  "fixed": "9a2e791639a1c5cac3f219b0d2632835d8f88d27"
                },
                {
                  "fixed": "03c512f22d3fbe7a3767d6df5e3d88b8e7c105e5"
                },
                {
                  "fixed": "dcb69ad0dafb4a24b825183bb94055d5be8a10bd"
                },
                {
                  "fixed": "a99d720ed2a5258564e5e9d5f39f3184a030d354"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89698.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.111"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.51"
                }
              ]
            },
            {
              "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-2026-89698.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:53.329786346Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/03c512f22d3fbe7a3767d6df5e3d88b8e7c105e5",
        "https://git.kernel.org/stable/c/9a2e791639a1c5cac3f219b0d2632835d8f88d27",
        "https://git.kernel.org/stable/c/a99d720ed2a5258564e5e9d5f39f3184a030d354",
        "https://git.kernel.org/stable/c/dcb69ad0dafb4a24b825183bb94055d5be8a10bd",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89698.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-89698",
        "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-2026-89698.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-89698",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 522332,
  "published_at": "2026-09-11T19:46:16.551+00:00"
}