CVE-2026-89669
Received
Received - Intake
Use-After-Free in Linux Kernel NFS Server
Vulnerability report for CVE-2026-89669, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-11
Last updated on: 2026-09-11
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
nfsd: initialize copy-notify stateid before publishing it
nfsd4_copy_notify() finished initializing the cpntf state after
nfs4_alloc_init_cpntf_state() had already linked it into the
s2s_cp_stateids IDR and the parent's sc_cp_list, with cs_count == 1 (the
membership reference) and none held for the caller. A racing
OFFLOAD_CANCEL (crafted cl_id == nn->s2s_cp_cl_id plus the guessable
so_id) could reach manage_cpntf_state() and free the entry, turning the
caller's subsequent cpn_cnr_stateid read and cp_p_stateid/cp_p_clid
writes into use-after-free. The owning clientid was also only recorded
after publication, so it could not gate an ownership check in that window.
Record cp_p_stateid and cp_p_clid inside nfs4_alloc_init_cpntf_state()
before nfs4_init_cp_state() publishes the entry, and return it with an
extra reference. The caller reads the stateid under that reference and
drops it with nfs4_put_cpntf_state(); on a late error the laundromat
reaps the entry.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
