High severity · published Sep 11, 2026
CVE-2026-89684
nfsd: fix cpntf publish race in nfs4_init_cp_state
7.5
CVSS
0.5%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 43% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
624322f1adc58acd0b69f77a6ddc764207e97241 before 63e18fc65587fd3f7b4c6d70e96d32fc41d82ba3; 624322f1adc58acd0b69f77a6ddc764207e97241 before 6ac469a274e3c7d87fc46ba46d83b95009680407; 624322f1adc58acd0b69f77a6ddc764207e97241 before 8eeca993357a0bc35aaefebfd7462ac7b0a21d9a; 624322f1adc58acd0b69f77a6ddc764207e97241 before bfeac42d9074e539bacd1898dd8c14b7f5776620; 624322f1adc58acd0b69f77a6ddc764207e97241 before 21d6c5957f5ca97d7352e60f55ea412beb9419f5; 624322f1adc58acd0b69f77a6ddc764207e97241 before a631a26a8777bb235eabd478bbbaf26a4db750bf; +3 more · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89684
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-89684
git.kernel.org
https://git.kernel.org/stable/c/21d6c5957f5ca97d7352e60f55ea412beb9419f5
git.kernel.org
https://git.kernel.org/stable/c/63e18fc65587fd3f7b4c6d70e96d32fc41d82ba3
git.kernel.org
https://git.kernel.org/stable/c/6ac469a274e3c7d87fc46ba46d83b95009680407
git.kernel.org
https://git.kernel.org/stable/c/8eeca993357a0bc35aaefebfd7462ac7b0a21d9a
git.kernel.org
https://git.kernel.org/stable/c/a631a26a8777bb235eabd478bbbaf26a4db750bf
git.kernel.org
https://git.kernel.org/stable/c/be3a5c1d857b0dcbc11796cea603ef25834f75b2
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