nfsd: fix cpntf publish race in nfs4_init_cp_state
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 5 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109, 6.18.50, 7.2.4, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Not affected: 3 products
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-02 Threatist record created from CVE-2026-89684
- 2026-10-03 Alias added: GHSA-83g2-j7m2-94hx
- 2026-10-05 EPSS moved to the below the 50th percentile
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-21 Affected versions changed · Red Hat
- 2026-10-21 CVSS score changed · Red Hat
- 2026-11-06 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/63e18fc65587fd3f7b4c6d70e96d32fc41d82ba3
- https://git.kernel.org/stable/c/6ac469a274e3c7d87fc46ba46d83b95009680407
- https://git.kernel.org/stable/c/8eeca993357a0bc35aaefebfd7462ac7b0a21d9a
- https://git.kernel.org/stable/c/bfeac42d9074e539bacd1898dd8c14b7f5776620
- https://git.kernel.org/stable/c/21d6c5957f5ca97d7352e60f55ea412beb9419f5
- https://git.kernel.org/stable/c/a631a26a8777bb235eabd478bbbaf26a4db750bf
- https://git.kernel.org/stable/c/c7270f62e7a05a2ee68aa2b74262b658a14463bd
- https://git.kernel.org/stable/c/be3a5c1d857b0dcbc11796cea603ef25834f75b2
More Linux vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-89684 · CVE Program
- CVE-2026-89684 · NVD
- FIRST EPSS
- GHSA-83g2-j7m2-94hx · GitHub Advisory Database · CC BY 4.0
- CVE-2026-89684 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences