CVE-2026-89698

Full vulnerability record from the local CVENow database.

Description

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

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-11 20:19:56.957000

Last modified

2026-10-19 09:18:08.400000

View original CVE JSON

{
  "id": "CVE-2026-89698",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-11T20:19:56.957",
  "lastModified": "2026-10-19T09:18:08.400",
  "vulnStatus": "Received",
  "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."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "fs/nfsd/nfsctl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "bd9d6a3efa9709e653aafbeb859289feccb8e70c",
              "lessThan": "9a2e791639a1c5cac3f219b0d2632835d8f88d27",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "bd9d6a3efa9709e653aafbeb859289feccb8e70c",
              "lessThan": "03c512f22d3fbe7a3767d6df5e3d88b8e7c105e5",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "bd9d6a3efa9709e653aafbeb859289feccb8e70c",
              "lessThan": "dcb69ad0dafb4a24b825183bb94055d5be8a10bd",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "bd9d6a3efa9709e653aafbeb859289feccb8e70c",
              "lessThan": "a99d720ed2a5258564e5e9d5f39f3184a030d354",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "fs/nfsd/nfsctl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.7",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.7",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.111",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.51",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.4",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/03c512f22d3fbe7a3767d6df5e3d88b8e7c105e5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9a2e791639a1c5cac3f219b0d2632835d8f88d27",
      "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",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}