# CVE-2026-89485

## Summary

- **CVE ID:** CVE-2026-89485
- **Severity:** CRITICAL
- **CVSS Score:** 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
- **CWE:** N/A
- **Published:** Sep 11, 2026
- **Last Modified:** Sep 14, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:

lockd: pin next file across nlm_inspect_file lock-drop

nlm_traverse_files() pins the current file with f_count++ across
a mutex_unlock for nlm_inspect_file(), but nothing pins the saved
next pointer.  A concurrent nlm_release_file() can kfree the next
file during the unlock window, and the iterator dereferences freed
memory on the next loop step.

Pin both current and next before the lock-drop.  Advance by
swapping the pinned cursors at the end of each iteration so next
is always held alive across the unlock.

Always call nlm_file_release() after dropping the iteration pin,
regardless of whether the file matched the predicate.  Use
nlm_file_inuse(), which does a live walk of the inode lock list,
rather than the cached f_locks field, so skipped files that never
ran nlm_inspect_file() are evaluated correctly.

Because every file in a hash bucket is now pinned and released,
files skipped by the is_failover_file predicate that have no
locks, blocks, shares, or external references are deleted during
traversal.  The old code never evaluated skipped files for
cleanup.  The new behavior is intentional: such files are stale
and should not persist in the table.

## Affected Products

- Linux — Linux (01df9c5e918ae5559f2d96da0143f8bfbb9e6171)
- Linux — Linux (2.6.18)
- Linux — Linux (0)
- Linux — Linux (6.12.109)
- Linux — Linux (6.18.50)
- Linux — Linux (7.2.4)
- Linux — Linux (7.3-rc1)
- Linux — Linux (5.10.270)
- Linux — Linux (5.15.221)
- Linux — Linux (6.1.188)
- Linux — Linux (6.6.157)

## References

- [CNA](https://git.kernel.org/stable/c/c24bdb7df2f34bdc38ca8a73796f5acb40f1830c)
- [CNA](https://git.kernel.org/stable/c/41f0a6d31615fcae261bf28a0aa50050dc93a401)
- [CNA](https://git.kernel.org/stable/c/e999a88133654c6dfc68487fb49da5f20dfa2d4f)
- [CNA](https://git.kernel.org/stable/c/526c49cff3f72c3ec74752016380c7567040581b)
- [CNA](https://git.kernel.org/stable/c/e3c413f789eaf0170275c7eba523ead73d963f30)
- [CNA](https://git.kernel.org/stable/c/08a455f87b14c7ff22ae3fdadda62a796a3a5572)
- [CNA](https://git.kernel.org/stable/c/550c19222c7132c888e23c9d89079ba1c9bc4cca)
- [CNA](https://git.kernel.org/stable/c/350087f231c11efcd288c310707c40eab63ca583)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.70%
- **EPSS Percentile:** 51.7

---
_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-19._