{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89667", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.745Z", "datePublished": "2026-09-11T19:45:53.609Z", "dateUpdated": "2026-10-19T08:50:40.641Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:50:40.641Z"}, "descriptions": [{"lang": "en", "value": "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."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.1, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - The vulnerable nfsd filecache GC, shrinker, and fsnotify close paths run in the in-kernel NFS server and are reached by NFS RPCs (OPEN/READ/WRITE/REMOVE) on TCP/UDP 2049 from a remote client; no local login is required.\nAC:H - Hitting the bug requires nfsd_file_cache_shutdown_net() to interleave with unhash plus delayed dispose; a remote client can populate the cache and trigger GC, shrinker, or fsnotify close, but cannot itself stop nfsd or destroy the server net namespace.\nPR:N - Typical nfsd deployments allow AUTH_SYS/AUTH_NULL with IP-based exports, so a remote peer that can reach the export self-asserts credentials with no cryptographic authentication and can populate the filecache via READ/WRITE.\nUI:N - Attacker-sent NFS operations drive the filecache side; no victim user action such as mounting a filesystem or opening a local file is required.\nS:U - The use-after-free or leak corrupts kernel nfsd_file/nfsd_net state within the host nfsd authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - Delayed dispose can call net_generic() and list_move on nfsd_net after per-net teardown frees it, a use-after-free of slab per-net data that enables reuse/spray and arbitrary kernel memory disclosure.\nI:H - The same freed nfsd_net is used for spin_lock and list_move_tail, a use-after-free write primitive that enables heap spraying, object corruption, and control-flow hijacking.\nA:H - Use-after-free of nfsd_net can oops or panic, and leaked nfsd_file objects permanently pin struct file/inode state so filesystem and netns teardown can hang, fully disrupting the NFS server host."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/nfsd/filecache.c"], "versions": [{"version": "ffb402596147ac583f3464ff5c48feb9423e3838", "lessThan": "b15997b53b61c74fb4d083f7261d19f389ff854f", "status": "affected", "versionType": "git"}, {"version": "ffb402596147ac583f3464ff5c48feb9423e3838", "lessThan": "6d6b9f6a75c3767250e9c23ace4e384ab8f7843e", "status": "affected", "versionType": "git"}, {"version": "ffb402596147ac583f3464ff5c48feb9423e3838", "lessThan": "08af9593e2b472fd98c00faf1bf03bdbb7203477", "status": "affected", "versionType": "git"}, {"version": "ffb402596147ac583f3464ff5c48feb9423e3838", "lessThan": "40162cfea79b9510380decfdd1795b754dc9f972", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/nfsd/filecache.c"], "versions": [{"version": "6.9", "status": "affected"}, {"version": "0", "lessThan": "6.9", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.51", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.12.111"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.18.51"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/b15997b53b61c74fb4d083f7261d19f389ff854f"}, {"url": "https://git.kernel.org/stable/c/6d6b9f6a75c3767250e9c23ace4e384ab8f7843e"}, {"url": "https://git.kernel.org/stable/c/08af9593e2b472fd98c00faf1bf03bdbb7203477"}, {"url": "https://git.kernel.org/stable/c/40162cfea79b9510380decfdd1795b754dc9f972"}], "title": "nfsd: close shrinker/GC/fsnotify vs per-net shutdown race in filecache", "x_generator": {"engine": "bippy-1.2.0"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/nfsd/filecache.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "b15997b53b61c74fb4d083f7261d19f389ff854f", "status": "affected", "version": "ffb402596147ac583f3464ff5c48feb9423e3838", "versionType": "git"}, {"lessThan": "6d6b9f6a75c3767250e9c23ace4e384ab8f7843e", "status": "affected", "version": "ffb402596147ac583f3464ff5c48feb9423e3838", "versionType": "git"}, {"lessThan": "08af9593e2b472fd98c00faf1bf03bdbb7203477", "status": "affected", "version": "ffb402596147ac583f3464ff5c48feb9423e3838", "versionType": "git"}, {"lessThan": "40162cfea79b9510380decfdd1795b754dc9f972", "status": "affected", "version": "ffb402596147ac583f3464ff5c48feb9423e3838", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/nfsd/filecache.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.9"}, {"lessThan": "6.9", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.111", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.51", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-89667", "lastModified": "2026-10-19T09:18:04.767", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-11T20:19:53.177", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/08af9593e2b472fd98c00faf1bf03bdbb7203477"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/40162cfea79b9510380decfdd1795b754dc9f972"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6d6b9f6a75c3767250e9c23ace4e384ab8f7843e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b15997b53b61c74fb4d083f7261d19f389ff854f"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel (nfsd): Memory leak due to race condition in file caching shutdown", "id": "2532484", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532484"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.3", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-772", "details": ["A flaw was found in the Linux kernel's Network File System Daemon (nfsd) file caching mechanism. A race condition can occur during concurrent shutdown operations and file disposal, where a file might be unhashed and moved to a dispose list, but the shutdown process misses it. This can lead to a memory leak, as the file and its associated state are not properly released, potentially resulting in a Denial of Service (DoS)."], "name": "CVE-2026-89667", "public_date": "2026-09-11T19:45:53Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89667\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89667\nhttps://git.kernel.org/stable/c/08af9593e2b472fd98c00faf1bf03bdbb7203477\nhttps://git.kernel.org/stable/c/40162cfea79b9510380decfdd1795b754dc9f972\nhttps://git.kernel.org/stable/c/6d6b9f6a75c3767250e9c23ace4e384ab8f7843e"], "threat_severity": "Moderate"}