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GHSA-CGQX-6JRP-48W7

Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-11 21:31

Details

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.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-89698"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T20:19:56Z",
    "severity": null
  },
  "details": "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": "GHSA-cgqx-6jrp-48w7",
  "modified": "2026-09-11T21:31:37Z",
  "published": "2026-09-11T21:31:37Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89698"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/03c512f22d3fbe7a3767d6df5e3d88b8e7c105e5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a99d720ed2a5258564e5e9d5f39f3184a030d354"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/dcb69ad0dafb4a24b825183bb94055d5be8a10bd"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

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

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.

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)

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{
  "containers": {
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      "affected": [
        {
          "defaultStatus": "unaffected",
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          "programFiles": [
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          "versions": [
            {
              "status": "affected",
              "version": "6.7"
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              "status": "unaffected",
              "version": "0",
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            },
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              "status": "unaffected",
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              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
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              "status": "unaffected",
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      "descriptions": [
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          "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."
        }
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}

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.
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