CVEvulnerability
CVE-2026-89709
8.1 HIGH
Official page ↗
- Status
- Received
- Published
- 2026-09-11
- Last modified
- 2026-10-21
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
- 8.1 HIGH — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Description
In the Linux kernel, the following vulnerability has been resolved:
lockd, nfsd: RCU-protect nlmsvc_ops dispatch
nlmsvc_ops is published by nfsd_lockd_init() and cleared by
nfsd_lockd_shutdown() with plain stores, while lockd dereferences
it unguarded from dispatch sites in fs/lockd/svcsubs.c. The pointer
targets nfsd's .rodata and the fopen/fclose callbacks live in nfsd's
.text, so a stale load after rmmod nfsd results in either a NULL
deref or a module-text use-after-free.
Declare nlmsvc_ops as __rcu, publish via rcu_assign_pointer(), clear
via RCU_INIT_POINTER() + synchronize_rcu(). Add a struct module
*owner field to nlmsvc_binding and pin the module across indirect
calls with try_module_get/module_put. When the binding is torn down,
fall back to fput() to avoid leaking struct file references.
References
- https://git.kernel.org/stable/c/3c461a1820088fb5889d73a6522369bde45527a9 git.kernel.org
- https://git.kernel.org/stable/c/43943532c105ea8fe26039a1347cfda4ac0fcadc git.kernel.org
- https://git.kernel.org/stable/c/641e5e20852359b8c31149be4598884e30652f60 git.kernel.org
- https://git.kernel.org/stable/c/6e7495972039f212e336e552b58cac9dd54611c3 git.kernel.org
- https://git.kernel.org/stable/c/836ce2b99bcce6d68c58edd04efbc5cd1fd581af git.kernel.org