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GHSA-83G2-J7M2-94HX

Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-14 15:32
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

nfsd: fix cpntf publish race in nfs4_init_cp_state

nfs4_alloc_init_cpntf_state() published the new cpntf entry into the s2s_cp_stateids IDR (with cs_type set) in one s2s_cp_lock section, then took the lock again to list_add() it onto p_stid->sc_cp_list. In the gap the entry is reachable by so_id but cp_list is still {NULL,NULL} from kzalloc. A racing OFFLOAD_CANCEL (so_id is echoed to the client as cnr_stateid, so any NFSv4.2 client can drive it) reaches manage_cpntf_state() -> _free_cpntf_state_locked() and does list_del() on the zeroed list_head, oopsing the server.

Fold the cs_type assignment and the list_add() into the same critical section as idr_alloc_cyclic(), so a concurrent lookup either misses the entry or sees a fully linked cp_list. INIT_LIST_HEAD() the entry after allocation and switch _free_cpntf_state_locked() to list_del_init() so a stale unlink is a no-op. nfs4_init_copy_state() passes NULL p_stid and skips the list_add, preserving NFS4_COPY_STID semantics.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-89684"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T20:19:55Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix cpntf publish race in nfs4_init_cp_state\n\nnfs4_alloc_init_cpntf_state() published the new cpntf entry into the\ns2s_cp_stateids IDR (with cs_type set) in one s2s_cp_lock section, then\ntook the lock again to list_add() it onto p_stid-\u003esc_cp_list. In the gap\nthe entry is reachable by so_id but cp_list is still {NULL,NULL} from\nkzalloc. A racing OFFLOAD_CANCEL (so_id is echoed to the client as\ncnr_stateid, so any NFSv4.2 client can drive it) reaches\nmanage_cpntf_state() -\u003e _free_cpntf_state_locked() and does list_del() on\nthe zeroed list_head, oopsing the server.\n\nFold the cs_type assignment and the list_add() into the same critical\nsection as idr_alloc_cyclic(), so a concurrent lookup either misses the\nentry or sees a fully linked cp_list. INIT_LIST_HEAD() the entry after\nallocation and switch _free_cpntf_state_locked() to list_del_init() so a\nstale unlink is a no-op. nfs4_init_copy_state() passes NULL p_stid and\nskips the list_add, preserving NFS4_COPY_STID semantics.",
  "id": "GHSA-83g2-j7m2-94hx",
  "modified": "2026-09-14T15:32:33Z",
  "published": "2026-09-11T21:31:36Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89684"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/21d6c5957f5ca97d7352e60f55ea412beb9419f5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/63e18fc65587fd3f7b4c6d70e96d32fc41d82ba3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6ac469a274e3c7d87fc46ba46d83b95009680407"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8eeca993357a0bc35aaefebfd7462ac7b0a21d9a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a631a26a8777bb235eabd478bbbaf26a4db750bf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/be3a5c1d857b0dcbc11796cea603ef25834f75b2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bfeac42d9074e539bacd1898dd8c14b7f5776620"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c7270f62e7a05a2ee68aa2b74262b658a14463bd"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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