Vulnerability-Lookup

FKIE_CVE-2026-89698

Vulnerability from fkie_nvd - Published: 2026-09-11 20:19 - Updated: 2026-09-11 20:19

Severity

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.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/03c512f22d3fbe7a3767d6df5e3d88b8e7c105e5
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/a99d720ed2a5258564e5e9d5f39f3184a030d354
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/dcb69ad0dafb4a24b825183bb94055d5be8a10bd

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/nfsd/nfsctl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "03c512f22d3fbe7a3767d6df5e3d88b8e7c105e5",
              "status": "affected",
              "version": "bd9d6a3efa9709e653aafbeb859289feccb8e70c",
              "versionType": "git"
            },
            {
              "lessThan": "dcb69ad0dafb4a24b825183bb94055d5be8a10bd",
              "status": "affected",
              "version": "bd9d6a3efa9709e653aafbeb859289feccb8e70c",
              "versionType": "git"
            },
            {
              "lessThan": "a99d720ed2a5258564e5e9d5f39f3184a030d354",
              "status": "affected",
              "version": "bd9d6a3efa9709e653aafbeb859289feccb8e70c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/nfsd/nfsctl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.7"
            },
            {
              "lessThan": "6.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.51",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: widen nfsd_genl_rqstp address fields to sockaddr_storage\n\nstruct nfsd_genl_rqstp declares rq_daddr and rq_saddr as plain\n\"struct sockaddr\" (16 bytes). When an IPv6 NFS client is connected,\nnfsd_genl_rpc_status_compose_msg() casts these fields to\n\"struct sockaddr_in6 *\" (28 bytes) and reads sin6_addr at offset 8..24,\nwhich extends 8 bytes past the end of the 16-byte sockaddr field into\nthe adjacent rq_flags member. The 16-byte nla_put_in6_addr then ships 8\nbytes of truncated IPv6 address followed by 8 bytes of rq_flags to\nuserspace via the NFSD_A_RPC_STATUS_SADDR6/DADDR6 netlink attributes.\n\nThis is reachable by any unprivileged process in the network namespace\nbecause NFSD_CMD_RPC_STATUS_GET uses GENL_CMD_CAP_DUMP without\nGENL_ADMIN_PERM.\n\nFix by widening rq_daddr and rq_saddr to struct sockaddr_storage so the\nIPv6 casts operate within bounds, copying sizeof(struct sockaddr_storage)\nbytes in the memcpy calls so the full address is captured, and\nzero-initializing the genl_rqstp stack variable to prevent leaking\nuninitialized tail bytes through netlink."
    }
  ],
  "id": "CVE-2026-89698",
  "lastModified": "2026-09-11T20:19:56.957",
  "metrics": {},
  "published": "2026-09-11T20:19:56.957",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/03c512f22d3fbe7a3767d6df5e3d88b8e7c105e5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a99d720ed2a5258564e5e9d5f39f3184a030d354"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/dcb69ad0dafb4a24b825183bb94055d5be8a10bd"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-89698 (GCVE-0-2026-89698)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:46 – Updated: 2026-09-11 19:46

Title

nfsd: widen nfsd_genl_rqstp address fields to sockaddr_storage

Summary

Severity

No CVSS data available.

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/03c512f22d3fbe7a3…
https://git.kernel.org/stable/c/dcb69ad0dafb4a24b…
https://git.kernel.org/stable/c/a99d720ed2a525856…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: bd9d6a3efa9709e653aafbeb859289feccb8e70c , < 03c512f22d3fbe7a3767d6df5e3d88b8e7c105e5 (git) Affected: bd9d6a3efa9709e653aafbeb859289feccb8e70c , < dcb69ad0dafb4a24b825183bb94055d5be8a10bd (git) Affected: bd9d6a3efa9709e653aafbeb859289feccb8e70c , < a99d720ed2a5258564e5e9d5f39f3184a030d354 (git)
Linux	Linux	Affected: 6.7 Unaffected: 0 , < 6.7 (semver) Unaffected: 6.18.51 , ≤ 6.18.* (semver) Unaffected: 7.2.4 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/nfsd/nfsctl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "03c512f22d3fbe7a3767d6df5e3d88b8e7c105e5",
              "status": "affected",
              "version": "bd9d6a3efa9709e653aafbeb859289feccb8e70c",
              "versionType": "git"
            },
            {
              "lessThan": "dcb69ad0dafb4a24b825183bb94055d5be8a10bd",
              "status": "affected",
              "version": "bd9d6a3efa9709e653aafbeb859289feccb8e70c",
              "versionType": "git"
            },
            {
              "lessThan": "a99d720ed2a5258564e5e9d5f39f3184a030d354",
              "status": "affected",
              "version": "bd9d6a3efa9709e653aafbeb859289feccb8e70c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/nfsd/nfsctl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.7"
            },
            {
              "lessThan": "6.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.51",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.51",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: widen nfsd_genl_rqstp address fields to sockaddr_storage\n\nstruct nfsd_genl_rqstp declares rq_daddr and rq_saddr as plain\n\"struct sockaddr\" (16 bytes). When an IPv6 NFS client is connected,\nnfsd_genl_rpc_status_compose_msg() casts these fields to\n\"struct sockaddr_in6 *\" (28 bytes) and reads sin6_addr at offset 8..24,\nwhich extends 8 bytes past the end of the 16-byte sockaddr field into\nthe adjacent rq_flags member. The 16-byte nla_put_in6_addr then ships 8\nbytes of truncated IPv6 address followed by 8 bytes of rq_flags to\nuserspace via the NFSD_A_RPC_STATUS_SADDR6/DADDR6 netlink attributes.\n\nThis is reachable by any unprivileged process in the network namespace\nbecause NFSD_CMD_RPC_STATUS_GET uses GENL_CMD_CAP_DUMP without\nGENL_ADMIN_PERM.\n\nFix by widening rq_daddr and rq_saddr to struct sockaddr_storage so the\nIPv6 casts operate within bounds, copying sizeof(struct sockaddr_storage)\nbytes in the memcpy calls so the full address is captured, and\nzero-initializing the genl_rqstp stack variable to prevent leaking\nuninitialized tail bytes through netlink."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-11T19:46:16.551Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/03c512f22d3fbe7a3767d6df5e3d88b8e7c105e5"
        },
        {
          "url": "https://git.kernel.org/stable/c/dcb69ad0dafb4a24b825183bb94055d5be8a10bd"
        },
        {
          "url": "https://git.kernel.org/stable/c/a99d720ed2a5258564e5e9d5f39f3184a030d354"
        }
      ],
      "title": "nfsd: widen nfsd_genl_rqstp address fields to sockaddr_storage",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89698",
    "datePublished": "2026-09-11T19:46:16.551Z",
    "dateReserved": "2026-09-11T19:38:34.750Z",
    "dateUpdated": "2026-09-11T19:46:16.551Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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