{"id":"CVE-2026-89702","summary":"nfsd: size fh_verify server sockaddr slot by xpt_locallen","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: size fh_verify server sockaddr slot by xpt_locallen\n\nThe nfsd_fh_verify and nfsd_fh_verify_err tracepoints declare the\nserver sockaddr slot sized by xpt_remotelen but fill it from\nxpt_local using xpt_locallen:\n\n    TP_STRUCT__entry(\n            ...\n            __sockaddr(server, rqstp-\u003erq_xprt-\u003expt_remotelen)\n            ...\n    )\n    TP_fast_assign(\n            ...\n            __assign_sockaddr(server, &rqstp-\u003erq_xprt-\u003expt_local,\n                              rqstp-\u003erq_xprt-\u003expt_locallen);\n            ...\n    )\n\nWhen xpt_locallen exceeds xpt_remotelen, __assign_sockaddr's memcpy\nwrites past the reserved ring-buffer slot. In the reverse direction\n(xpt_locallen \u003c xpt_remotelen) the slot is oversized and the\nunwritten tail leaks prior ring-buffer contents to trace consumers.\n\nThe write-past-end case is reachable on NFS/UDP. svc_xprt_set_remote()\nis only called from svc_tcp_accept() (net/sunrpc/svcsock.c) and from\nthe RDMA connect path; svc_create_socket() for UDP calls only\nsvc_xprt_set_local(), so xpt_remotelen stays 0 for the xprt's\nlifetime. Every fh_verify trace for an NFSv2/v3-over-UDP request\nthen copies 16 or 28 bytes from xpt_local into a zero-byte slot.\n\nThe other NFSD tracepoints that record the server address\n(NFSD_TRACE_PROC_CALL_FIELDS, NFSD_TRACE_PROC_RES_FIELDS,\nSVC_RQST_ENDPOINT_FIELDS) already size the server slot by\nxpt_locallen; nfsd_fh_verify and nfsd_fh_verify_err were the only\nexceptions.\n\nFix by sizing the server slot with xpt_locallen so the declared slot\nmatches the copy length. The client slot and its assignment already\nagree on xpt_remotelen and are left untouched.","modified":"2026-11-01T02:31:03.984675996Z","published":"2026-09-11T19:46:19.537Z","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-2026:4660-1","SUSE-SU-2026:4706-1","openSUSE-SU-2026:11880-1","openSUSE-SU-2026:22091-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89702.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1c6a4d6c20fd42552ffc2c3dfaed2139c9477ee5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4c7569ad68fc8b86ca40c7e56ef21460c0344955"},{"type":"WEB","url":"https://git.kernel.org/stable/c/50d9d581d2af80799125ee62617d37e9b6b476a7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/719a10e3f5f868c3c4ac3cf3648c5775d12034bd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/71d068490098b1d23c63b2345e40675d3a1ca763"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7ff8d6363cffff45654ea85e319f7c0c54226012"},{"type":"WEB","url":"https://git.kernel.org/stable/c/95d064f9828a20ccca5ae90a17be3e2076f25272"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89702.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89702"},{"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":"dcbebc86850324fbe0a993ce352f0539cd98038a"},{"fixed":"4c7569ad68fc8b86ca40c7e56ef21460c0344955"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"051382885552e12541cc0ebf82092be374a9ed2a"},{"fixed":"50d9d581d2af80799125ee62617d37e9b6b476a7"},{"fixed":"1c6a4d6c20fd42552ffc2c3dfaed2139c9477ee5"},{"fixed":"95d064f9828a20ccca5ae90a17be3e2076f25272"},{"fixed":"7ff8d6363cffff45654ea85e319f7c0c54226012"},{"fixed":"719a10e3f5f868c3c4ac3cf3648c5775d12034bd"},{"fixed":"71d068490098b1d23c63b2345e40675d3a1ca763"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.15.154"},{"fixed":"5.15.224"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"62980365d6e894234b29f44fb2bfad4f7f8bb824"}]}],"versions":["v5.15.223","v5.15.222","v5.15.221","v5.15.220","v5.15.219","v5.15.218","v5.15.217","v5.15.216","v5.15.215","v5.15.214","v5.15.213","v5.15.212","v5.15.211","v5.15.210","v5.15.209","v5.15.208","v5.15.207","v5.15.206","v5.15.205","v5.15.204","v5.15.203","v5.15.202","v5.15.201","v5.15.200","v5.15.199","v5.15.198","v5.15.197","v5.15.196","v5.15.195","v5.15.194","v5.15.193","v5.15.192","v5.15.191","v5.15.190","v5.15.189","v5.15.188","v5.15.187","v5.15.186","v5.15.185","v5.15.184","v5.15.183","v5.15.182","v5.15.181","v5.15.180","v5.15.179","v5.15.178","v5.15.177","v5.15.176","v5.15.175","v5.15.174","v5.15.173","v5.15.172","v5.15.171","v5.15.170","v5.15.169","v5.15.168","v5.15.167","v5.15.166","v5.15.165","v5.15.164","v5.15.163","v5.15.162","v5.15.161","v5.15.160","v5.15.159","v5.15.158","v5.15.157","v5.15.156","v5.15.155","v5.15.154","v5.15.224"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89702.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.224"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.191"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.0.0"},{"fixed":"6.6.160"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.12.109"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.18.50"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89702.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"}]}