CVE-2026-89698 (GCVE-0-2026-89698)
Vulnerability from cvelistv5
Published
2026-09-11 19:46
Modified
2026-10-19 08:51
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
Impacted products
Vendor Product Version
Linux Linux Version: bd9d6a3efa9709e653aafbeb859289feccb8e70c
Version: bd9d6a3efa9709e653aafbeb859289feccb8e70c
Version: bd9d6a3efa9709e653aafbeb859289feccb8e70c
Version: bd9d6a3efa9709e653aafbeb859289feccb8e70c
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{
  "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": "9a2e791639a1c5cac3f219b0d2632835d8f88d27",
              "status": "affected",
              "version": "bd9d6a3efa9709e653aafbeb859289feccb8e70c",
              "versionType": "git"
            },
            {
              "lessThan": "03c512f22d3fbe7a3767d6df5e3d88b8e7c105e5",
              "status": "affected",
              "version": "bd9d6a3efa9709e653aafbeb859289feccb8e70c",
              "versionType": "git"
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              "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": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "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",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.111",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "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",
                  "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": "2026-10-19T08:51:11.410Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/9a2e791639a1c5cac3f219b0d2632835d8f88d27"
        },
        {
          "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": "2026-10-19T08:51:11.410Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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