CVE-2026-89709

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.

Score

CVSS 3.1 8.1 High

Status

Received - 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-11

Last modified

2026-10-21

Affected products

• Linux Kernel (Linux)

References

• https://git.kernel.org/stable/c/43943532c105ea8fe26039a1347cfda4ac0fcadc
• https://git.kernel.org/stable/c/6e7495972039f212e336e552b58cac9dd54611c3
• https://git.kernel.org/stable/c/836ce2b99bcce6d68c58edd04efbc5cd1fd581af
• https://git.kernel.org/stable/c/3c461a1820088fb5889d73a6522369bde45527a9
• https://git.kernel.org/stable/c/641e5e20852359b8c31149be4598884e30652f60