{"id":"CVE-2026-89685","summary":"nfsd: fix clock domain mismatch in clients_still_reclaiming()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix clock domain mismatch in clients_still_reclaiming()\n\nclients_still_reclaiming() computes a deadline from nn-\u003eboot_time\n(CLOCK_REALTIME, ~1.7 billion) but compares it against\nktime_get_boottime_seconds() (CLOCK_BOOTTIME, seconds since boot).\nThe comparison is always false — it would take ~54 years of uptime\nfor BOOTTIME to exceed the REALTIME-derived deadline.\n\nThis means any client can hold the server in grace indefinitely by\nsending CLAIM_PREVIOUS OPEN requests, blocking all non-reclaim\noperations for all other clients.\n\nAdd boot_time_bt (CLOCK_BOOTTIME) alongside the existing boot_time\nand use it for the deadline computation. boot_time (CLOCK_REALTIME)\nis preserved for its cl_boot clientid-nonce role.","modified":"2026-09-13T03:47:20.142456298Z","published":"2026-09-11T19:46:07.116Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89685.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/09ea3eb9a518565f5bca386e81b993ed8825f5e8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9843649196221152b6e5d138a3ce859bdaae1d96"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f9cec313efb2fd18d962aad738a4892bce806016"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89685.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89685"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"20b7d86f29d39e8ae19bb29c24ffee70dc385ddf"},{"fixed":"f9cec313efb2fd18d962aad738a4892bce806016"},{"fixed":"9843649196221152b6e5d138a3ce859bdaae1d96"},{"fixed":"09ea3eb9a518565f5bca386e81b993ed8825f5e8"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89685.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.6.0"},{"fixed":"6.18.51"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89685.json"}}],"schema_version":"1.9.0"}