{"id":"CVE-2026-89660","revision":"19f099158a954cad9c6e498bcda8b79f","records":[{"revision":"19f099158a954cad9c6e498bcda8b79f","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89660","aliases":[],"title":"NFSD: Prevent client use-after-free during admin state revocation","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Prevent client use-after-free during admin state revocation\n\nA stateid holds only a bare pointer to its nfs4_client; a stateid\nreference does not pin it.  The client survives only because\n__destroy_client() drains its stateids before free_client() runs.\n\nnfsd4_revoke_states() drops nn->client_lock across revoke_one_stid(),\nwhich dereferences the client to revoke a stateid and read\nclp->cl_minorversion.  A teardown racing the dropped lock can free\nthe client first.\n\nPinning cl_rpc_users under client_lock blocks the DESTROY_CLIENTID and\nEXCHANGE_ID teardown, which refuses while cl_rpc_users is non-zero.\nforce_expire_client() ignores it: once its wait for cl_rpc_users to\nreach zero has passed, a later pin goes unnoticed.\n\nUnder client_lock, skip a client whose cl_time is already zero --\nforce_expire_client() clears it there before waiting -- otherwise pin\ncl_rpc_users before dropping the lock.  The walk then either sees the\nexpiry and skips, or pins in time for that wait to cover the revoke.","state":0,"publishedAt":"2026-09-11T19:45:48.341+00:00","modifiedAt":"2026-10-19T08:50:31.845+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/nfsd/nfs4state.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc\",\n                            \"lessThan\": \"e1ba4d3c5bfdca3f013b8cbc829ae2f7975d8608\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc\",\n                            \"lessThan\": \"549bd9868e9d77b07ea94870940d64342829c6ad\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc\",\n                            \"lessThan\": \"bf1f948691523282cc4905bc6cd325e0c0b49e6a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc\",\n                            \"lessThan\": \"e270e5a0778e5bff852c8862ce9576ce70359393\",\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/nfsd/nfs4state.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.9\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.9\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.111\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.51\",\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":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8,"severity":"CRITICAL"}],"references":["https://git.kernel.org/stable/c/e1ba4d3c5bfdca3f013b8cbc829ae2f7975d8608","https://git.kernel.org/stable/c/549bd9868e9d77b07ea94870940d64342829c6ad","https://git.kernel.org/stable/c/bf1f948691523282cc4905bc6cd325e0c0b49e6a","https://git.kernel.org/stable/c/e270e5a0778e5bff852c8862ce9576ce70359393"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89660","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89660","identifiers":["CVE-2026-89660"]},"retained":false,"historicalAffected":[]}],"coverage":[]}