CVE-2026-89667nfsd: close shrinker/GC/fsnotify vs per-net shutdown race in filecache
- 8.1HighCVSS base score
- 0.54%Exploitation in 30 daysEPSS · top 54% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: nfsd: close shrinker/GC/fsnotify vs per-net shutdown race in filecache The shrinker, GC worker, and fsnotify/lease callbacks can unhash an nfsd_file from the rhashtable and then call nfsd_file_dispose_list_delayed() to move it to the per-net dispose list. If nfsd_file_cache_shutdown_net() runs concurrently, its rhashtable walk misses the already-unhashed file, and its drain of the per-net dispose list can run before the file has been queued. The file then sits on the per-net list with no thread to drain it, leaking both the file and its associated state. The GC worker and shrinker already hold nfsd_gc_lock while walking the LRU, but in the original code they release it before calling nfsd_file_dispose_list_delayed(). The fsnotify/lease path (nfsd_file_close_inode) has no synchronization at all. Fix this by: 1. Widening nfsd_gc_lock in both nfsd_file_gc() and nfsd_file_lru_scan() to cover the nfsd_file_dispose_list_delayed() call. 2. Wrapping nfsd_file_close_inode() in nfsd_gc_lock so that all three callers of nfsd_file_dispose_list_delayed() hold the lock. 3. Adding a spin_lock/unlock(nfsd_gc_lock) barrier in nfsd_file_cache_shutdown_net() after the purge, so that any in-progress disposal has fully completed before the per-net list is drained. All operations inside the lock are non-sleeping (rhashtable lookups, atomic bit/refcount ops, list moves, svc_wake_up), so the spinlock is appropriate.
Timeline
ID reserved
By Linux
Published
- 38 days later
· 38 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Received | 3.1 | High8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.54% · top 54% of all CVEs (14 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.1.
Affected products
- affected ffb402596147ac583f3464ff5c48feb9423e3838 – < b15997b53b61c74fb4d083f7261d19f389ff854f
- affected ffb402596147ac583f3464ff5c48feb9423e3838 – < 6d6b9f6a75c3767250e9c23ace4e384ab8f7843e
- affected ffb402596147ac583f3464ff5c48feb9423e3838 – < 08af9593e2b472fd98c00faf1bf03bdbb7203477
- affected ffb402596147ac583f3464ff5c48feb9423e3838 – < 40162cfea79b9510380decfdd1795b754dc9f972
- affected 6.9
- unaffected < 6.9
- unaffected 6.12.111 – ≤ 6.12.*
- unaffected 6.18.51 – ≤ 6.18.*
- unaffected 7.2.4 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References4
- https://git.kernel.org/stable/c/b15997b53b61c74fb4d083f7261d19f389ff854f (opens in a new tab)
- https://git.kernel.org/stable/c/6d6b9f6a75c3767250e9c23ace4e384ab8f7843e (opens in a new tab)
- https://git.kernel.org/stable/c/08af9593e2b472fd98c00faf1bf03bdbb7203477 (opens in a new tab)
- https://git.kernel.org/stable/c/40162cfea79b9510380decfdd1795b754dc9f972 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-76579 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-89667)Record last updated .