{"id":"CVE-2026-89686","summary":"nfsd: fix BUG_ON in nfsd4_alloc_layout_stateid on racing delegation revoke","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix BUG_ON in nfsd4_alloc_layout_stateid on racing delegation revoke\n\nnfsd4_alloc_layout_stateid reads fp-\u003efi_deleg_file without holding\nfi_lock when the parent stateid is a delegation. A concurrent delegation\nrevoke via the laundromat can clear fi_deleg_file under fi_lock, causing\nnfsd_file_get() to return NULL and triggering the BUG_ON.\n\nThis race is client-reachable: two NFS clients can trigger it by having\none hold a delegation while another opens the same file to force a\nrecall. When the first client doesn't respond to the recall, the\nlaundromat revokes it. A concurrent LAYOUTGET from any client using the\ndelegation stateid hits the race window.\n\nFix this by taking fi_lock around the fi_deleg_file read in the\nSC_TYPE_DELEG path, matching the locking discipline of the\nfind_any_file() arm, and replacing the BUG_ON with a graceful error\nreturn that cleans up the partially-initialized layout stateid.","modified":"2026-11-01T02:30:29.096869557Z","published":"2026-09-11T19:46:07.877Z","related":["SUSE-SU-2026:24179-1","SUSE-SU-2026:24181-1","SUSE-SU-2026:24182-1","SUSE-SU-2026:24184-1","SUSE-SU-2026:24197-1","SUSE-SU-2026:24235-1","SUSE-SU-2026:24315-1","SUSE-SU-2026:24316-1","SUSE-SU-2026:4640-1","SUSE-SU-2026:4687-1","SUSE-SU-2026:4706-1","openSUSE-SU-2026:11805-1","openSUSE-SU-2026:22091-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89686.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/607a56fea772c1f4f4989d8e255dd4f7192d9604"},{"type":"WEB","url":"https://git.kernel.org/stable/c/97bda8b4284d90897a1f1922e5082ff9e35d7c7e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c517f27498757e616d2a8fe6d16caad1fee422e6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ca94ba36172046be6a694a7986f6931e47ed4d51"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d12af460df27876661707efab3a8532146cb961f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f5011c26246d1abed3dc750c9744e33cb79ff9bc"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89686.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89686"},{"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":"c5c707f96fc9a6e5a57ca5baac892673270abe3d"},{"fixed":"f5011c26246d1abed3dc750c9744e33cb79ff9bc"},{"fixed":"d12af460df27876661707efab3a8532146cb961f"},{"fixed":"c517f27498757e616d2a8fe6d16caad1fee422e6"},{"fixed":"607a56fea772c1f4f4989d8e255dd4f7192d9604"},{"fixed":"97bda8b4284d90897a1f1922e5082ff9e35d7c7e"},{"fixed":"ca94ba36172046be6a694a7986f6931e47ed4d51"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89686.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"6.1.191"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.160"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.109"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.50"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89686.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}