CVE-2026-89684

Status: UPDATED  |  Advisory ID: CVE-2026-89684

Key Details

Affected Products, Subsystems & Sectors

What to Know

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. (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References