Status: UPDATED | Advisory ID: CVE-2026-90036
| CVE | CVE-2026-90036 |
| CVSS Score / Version | 9.8 (Critical) / CVSS v3.1 |
| Updated | 2026-09-21 |
| CVSS Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| CVSS Prose | attack vector is network; attack complexity is low; privileges required is none; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high. |
| Affected products | Linux Linux |
| Vendor | Product | Affected Versions | Patch Status |
|---|---|---|---|
| Linux | Linux |
| Subsystems | General OT |
| Sectors | Multiple |
In the Linux kernel, the following vulnerability has been resolved:
NFSD: Prevent client use-after-free during blocked-lock reaping
A bare lock owner -- its only remaining reference a blocked lock on
nn->blocked_locks_lru -- holds a raw pointer to its nfs4_client but
no reference keeping the client alive. When the per-net laundromat
reaps such a lock, freeing the nbl drops the owner reference
held through flc_owner, and the final nfs4_put_stateowner()
takes the client's cl_lock. Because the laundromat detaches the
nbl first, __destroy_client() no longer finds it, so a concurrent
force_expire_client() can free the client before nfs4_put_stateowner()
runs, dereferencing cl_lock in freed memory.
Pin the client with cl_rpc_users before dropping
nn->blocked_locks_lock, and skip clients already expiring, whose
blocked locks __destroy_client() frees while holding an owner
reference. Take nn->client_lock outside nn->blocked_locks_lock.
Every other site holds nn->blocked_locks_lock as a leaf, acquiring
no further lock, so placing nn->client_lock outside it cannot form
a lock-order cycle. (NVD)
Monitor Linux's web page for any future patch releases.
| Source | Reference |
|---|---|
| NVD | https://nvd.nist.gov/vuln/detail/CVE-2026-90036 |
| CVE | https://www.cve.org/CVERecord?id=CVE-2026-90036 |