{"id":"CVE-2026-89714","revision":"0468969ce4ad474f96d65aa3f7af66aa","records":[{"revision":"0468969ce4ad474f96d65aa3f7af66aa","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89714","aliases":[],"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":0,"publishedAt":"2026-09-11T19:46:28.476+00:00","modifiedAt":"2026-10-19T08:51:27.182+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/nfs/nfs4client.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"f5b3108e6a14418b120a3c38ca589b8d6cf87627\",\n                            \"lessThan\": \"f3adf1643517357221422c05986d6de5df7b9913\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f5b3108e6a14418b120a3c38ca589b8d6cf87627\",\n                            \"lessThan\": \"0fd2b9687dae36be5b84eab39b4c627bb7ab33b3\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f5b3108e6a14418b120a3c38ca589b8d6cf87627\",\n                            \"lessThan\": \"2092f5b38f88be306140c77aeeeb43fc1adacacc\",\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/nfs/nfs4client.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.17\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.17\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.50\",\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":[],"references":["https://git.kernel.org/stable/c/f3adf1643517357221422c05986d6de5df7b9913","https://git.kernel.org/stable/c/0fd2b9687dae36be5b84eab39b4c627bb7ab33b3","https://git.kernel.org/stable/c/2092f5b38f88be306140c77aeeeb43fc1adacacc"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89714","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89714","identifiers":["CVE-2026-89714"]},"retained":false,"historicalAffected":[]}],"coverage":[]}