CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's handling of the nlmsvc_ops pointer within the NFS lock daemon (lockd), which can lead to a NULL dereference or a use-after-free condition after the nfsd module is removed. This flaw poses a risk of system instability or potential exploitation through crafted NFS requests. Organizations utilizing Linux systems with NFS services should prioritize addressing this vulnerability to maintain system integrity and security.
Original NVD 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.