{"api_version":"1","generated_at":"2026-09-11T21:24:31+00:00","cve":"CVE-2026-89714","urls":{"html":"https://cve.report/CVE-2026-89714","api":"https://cve.report/api/cve/CVE-2026-89714.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89714","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89714"},"summary":{"title":"NFS: fix delegation_hash_table leak when nfs4_server_common_setup() fails","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFS: fix delegation_hash_table leak when nfs4_server_common_setup() fails\n\nnfs4_server_common_setup() allocates server->delegation_hash_table\nfirst, but server->destroy - the only path that frees the table via\nnfs4_destroy_server() - is not assigned until the very end of the\nfunction. If any intermediate step fails (the is_ds_only_client()\ncheck, nfs4_init_session(), nfs4_get_rootfh(), or nfs_probe_server()),\nthe function returns with server->destroy still NULL, so the caller's\nnfs_free_server() skips the destroy callback and the hash table is\nleaked (4 KiB per attempt with the default delegation watermark).\n\nThis is trivially reachable from userspace: every failed NFSv4 mount\nleaks one allocation. A client that persistently retries a mount that\ncannot succeed leaks kernel memory without bound. Observed in\nproduction where a Longhorn backup poller retried mount.nfs4 against\nan NFSv3-only server roughly 10 times per second, leaking ~3.4 GiB of\nunreclaimable slab (kmalloc-rnd-13-4k) per day; the node accumulated\n12 GiB of leaked slab before the source was identified via the\nkmem:kmalloc tracepoint (call_site=nfs4_delegation_hash_alloc).\n\nReproducer:\n\n  # server exports NFSv3 only (or export path absent for v4)\n  while :; do mount -t nfs4 <server>:/missing /mnt; done\n  # watch SUnreclaim in /proc/meminfo grow 4 KiB per iteration\n\nFree the table on the error paths between the allocation and the\nassignment of server->destroy.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:19:58","updated_at":"2026-09-11 20:19:58"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/0fd2b9687dae36be5b84eab39b4c627bb7ab33b3","name":"https://git.kernel.org/stable/c/0fd2b9687dae36be5b84eab39b4c627bb7ab33b3","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2092f5b38f88be306140c77aeeeb43fc1adacacc","name":"https://git.kernel.org/stable/c/2092f5b38f88be306140c77aeeeb43fc1adacacc","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f3adf1643517357221422c05986d6de5df7b9913","name":"https://git.kernel.org/stable/c/f3adf1643517357221422c05986d6de5df7b9913","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89714","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89714","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f5b3108e6a14418b120a3c38ca589b8d6cf87627 f3adf1643517357221422c05986d6de5df7b9913 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f5b3108e6a14418b120a3c38ca589b8d6cf87627 0fd2b9687dae36be5b84eab39b4c627bb7ab33b3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f5b3108e6a14418b120a3c38ca589b8d6cf87627 2092f5b38f88be306140c77aeeeb43fc1adacacc git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.17","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.17 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.50 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/nfs/nfs4client.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"f3adf1643517357221422c05986d6de5df7b9913","status":"affected","version":"f5b3108e6a14418b120a3c38ca589b8d6cf87627","versionType":"git"},{"lessThan":"0fd2b9687dae36be5b84eab39b4c627bb7ab33b3","status":"affected","version":"f5b3108e6a14418b120a3c38ca589b8d6cf87627","versionType":"git"},{"lessThan":"2092f5b38f88be306140c77aeeeb43fc1adacacc","status":"affected","version":"f5b3108e6a14418b120a3c38ca589b8d6cf87627","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/nfs/nfs4client.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.17"},{"lessThan":"6.17","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.50","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.50","versionStartIncluding":"6.17","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"6.17","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"6.17","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFS: fix delegation_hash_table leak when nfs4_server_common_setup() fails\n\nnfs4_server_common_setup() allocates server->delegation_hash_table\nfirst, but server->destroy - the only path that frees the table via\nnfs4_destroy_server() - is not assigned until the very end of the\nfunction. If any intermediate step fails (the is_ds_only_client()\ncheck, nfs4_init_session(), nfs4_get_rootfh(), or nfs_probe_server()),\nthe function returns with server->destroy still NULL, so the caller's\nnfs_free_server() skips the destroy callback and the hash table is\nleaked (4 KiB per attempt with the default delegation watermark).\n\nThis is trivially reachable from userspace: every failed NFSv4 mount\nleaks one allocation. A client that persistently retries a mount that\ncannot succeed leaks kernel memory without bound. Observed in\nproduction where a Longhorn backup poller retried mount.nfs4 against\nan NFSv3-only server roughly 10 times per second, leaking ~3.4 GiB of\nunreclaimable slab (kmalloc-rnd-13-4k) per day; the node accumulated\n12 GiB of leaked slab before the source was identified via the\nkmem:kmalloc tracepoint (call_site=nfs4_delegation_hash_alloc).\n\nReproducer:\n\n  # server exports NFSv3 only (or export path absent for v4)\n  while :; do mount -t nfs4 <server>:/missing /mnt; done\n  # watch SUnreclaim in /proc/meminfo grow 4 KiB per iteration\n\nFree the table on the error paths between the allocation and the\nassignment of server->destroy."}],"providerMetadata":{"dateUpdated":"2026-09-11T19:46:28.476Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/f3adf1643517357221422c05986d6de5df7b9913"},{"url":"https://git.kernel.org/stable/c/0fd2b9687dae36be5b84eab39b4c627bb7ab33b3"},{"url":"https://git.kernel.org/stable/c/2092f5b38f88be306140c77aeeeb43fc1adacacc"}],"title":"NFS: fix delegation_hash_table leak when nfs4_server_common_setup() fails","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89714","datePublished":"2026-09-11T19:46:28.476Z","dateReserved":"2026-09-11T19:38:34.751Z","dateUpdated":"2026-09-11T19:46:28.476Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:19:58","lastModifiedDate":"2026-09-11 20:19:58","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89714","Ordinal":"1","Title":"NFS: fix delegation_hash_table leak when nfs4_server_common_setu","CVE":"CVE-2026-89714","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89714","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFS: fix delegation_hash_table leak when nfs4_server_common_setup() fails\n\nnfs4_server_common_setup() allocates server->delegation_hash_table\nfirst, but server->destroy - the only path that frees the table via\nnfs4_destroy_server() - is not assigned until the very end of the\nfunction. If any intermediate step fails (the is_ds_only_client()\ncheck, nfs4_init_session(), nfs4_get_rootfh(), or nfs_probe_server()),\nthe function returns with server->destroy still NULL, so the caller's\nnfs_free_server() skips the destroy callback and the hash table is\nleaked (4 KiB per attempt with the default delegation watermark).\n\nThis is trivially reachable from userspace: every failed NFSv4 mount\nleaks one allocation. A client that persistently retries a mount that\ncannot succeed leaks kernel memory without bound. Observed in\nproduction where a Longhorn backup poller retried mount.nfs4 against\nan NFSv3-only server roughly 10 times per second, leaking ~3.4 GiB of\nunreclaimable slab (kmalloc-rnd-13-4k) per day; the node accumulated\n12 GiB of leaked slab before the source was identified via the\nkmem:kmalloc tracepoint (call_site=nfs4_delegation_hash_alloc).\n\nReproducer:\n\n  # server exports NFSv3 only (or export path absent for v4)\n  while :; do mount -t nfs4 <server>:/missing /mnt; done\n  # watch SUnreclaim in /proc/meminfo grow 4 KiB per iteration\n\nFree the table on the error paths between the allocation and the\nassignment of server->destroy.","Type":"Description","Title":"NFS: fix delegation_hash_table leak when nfs4_server_common_setu"}]}}}