{"id":"CVE-2026-89667","revision":"36ca9f1f441d4e8f904caa5028846c5c","records":[{"revision":"36ca9f1f441d4e8f904caa5028846c5c","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89667","aliases":[],"title":"nfsd: close shrinker/GC/fsnotify vs per-net shutdown race in filecache","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: close shrinker/GC/fsnotify vs per-net shutdown race in filecache\n\nThe shrinker, GC worker, and fsnotify/lease callbacks can unhash an\nnfsd_file from the rhashtable and then call\nnfsd_file_dispose_list_delayed() to move it to the per-net dispose list.\nIf nfsd_file_cache_shutdown_net() runs concurrently, its rhashtable walk\nmisses the already-unhashed file, and its drain of the per-net dispose\nlist can run before the file has been queued.  The file then sits on\nthe per-net list with no thread to drain it, leaking both the file and\nits associated state.\n\nThe GC worker and shrinker already hold nfsd_gc_lock while walking the\nLRU, but in the original code they release it before calling\nnfsd_file_dispose_list_delayed().  The fsnotify/lease path\n(nfsd_file_close_inode) has no synchronization at all.\n\nFix this by:\n\n  1. Widening nfsd_gc_lock in both nfsd_file_gc() and nfsd_file_lru_scan()\n     to cover the nfsd_file_dispose_list_delayed() call.\n\n  2. Wrapping nfsd_file_close_inode() in nfsd_gc_lock so that all three\n     callers of nfsd_file_dispose_list_delayed() hold the lock.\n\n  3. Adding a spin_lock/unlock(nfsd_gc_lock) barrier in\n     nfsd_file_cache_shutdown_net() after the purge, so that any\n     in-progress disposal has fully completed before the per-net list\n     is drained.\n\nAll operations inside the lock are non-sleeping (rhashtable lookups,\natomic bit/refcount ops, list moves, svc_wake_up), so the spinlock is\nappropriate.","state":0,"publishedAt":"2026-09-11T19:45:53.609+00:00","modifiedAt":"2026-10-19T08:50:40.641+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/nfsd/filecache.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"ffb402596147ac583f3464ff5c48feb9423e3838\",\n                            \"lessThan\": \"b15997b53b61c74fb4d083f7261d19f389ff854f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ffb402596147ac583f3464ff5c48feb9423e3838\",\n                            \"lessThan\": \"6d6b9f6a75c3767250e9c23ace4e384ab8f7843e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ffb402596147ac583f3464ff5c48feb9423e3838\",\n                            \"lessThan\": \"08af9593e2b472fd98c00faf1bf03bdbb7203477\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ffb402596147ac583f3464ff5c48feb9423e3838\",\n                            \"lessThan\": \"40162cfea79b9510380decfdd1795b754dc9f972\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/nfsd/filecache.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.9\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.9\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.111\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.51\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.4\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.1,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/b15997b53b61c74fb4d083f7261d19f389ff854f","https://git.kernel.org/stable/c/6d6b9f6a75c3767250e9c23ace4e384ab8f7843e","https://git.kernel.org/stable/c/08af9593e2b472fd98c00faf1bf03bdbb7203477","https://git.kernel.org/stable/c/40162cfea79b9510380decfdd1795b754dc9f972"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89667","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89667","identifiers":["CVE-2026-89667"]},"retained":false,"historicalAffected":[]}],"coverage":[]}