High severity · published Sep 11, 2026
CVE-2026-89709
lockd, nfsd: RCU-protect nlmsvc_ops dispatch
8.1
CVSS
0.6%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 46% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 43943532c105ea8fe26039a1347cfda4ac0fcadc; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 6e7495972039f212e336e552b58cac9dd54611c3; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 836ce2b99bcce6d68c58edd04efbc5cd1fd581af; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 3c461a1820088fb5889d73a6522369bde45527a9; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 641e5e20852359b8c31149be4598884e30652f60; 2.6.12 · source: vendor