CVE-2026-90036

CVE CVE-2026-90036EUVD EUVD-2026-80644Published 2026-09-16T10:33:35.000ZLast changed 2026-09-21T13:15:12.000ZCVSS 9.8

What the advisory describes

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.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux 4.9; 7919d0a27f1e7cb324e023776aa1cbff00f1ee7b <9026932ac8be4d0ae01db47f23619a98cc57b671; patch: 6.18.51; patch: 0; 7919d0a27f1e7cb324e023776aa1cbff00f1ee7b <cd489b03587378645fe0d20142a33f1ed60bac98; patch: 6.12.111; 7919d0a27f1e7cb324e023776aa1cbff00f1ee7b <6fedb2eaff77554ca7a0deffd2e8bc0d6e8b38b0; 7919d0a27f1e7cb324e023776aa1cbff00f1ee7b <7081224a59a0ca4edcd62c068588f4d900199a18; patch: 7.2.5; patch: 7.3-rc1

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

Patchlage reports hits and suspected hits. About everything else this system says nothing — neither this page nor the situation report ever claims that an estate is safe.