{"id":"CVE-2026-89702","title":"nfsd: size fh_verify server sockaddr slot by xpt_locallen","summary":"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…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-787"],"vendor":"Linux","product":"Linux","affected":["Linux >= 051382885552e12541cc0ebf82092be374a9ed2a < 1c6a4d6c20fd42552ffc2c3dfaed2139c9477ee5","Linux >= 051382885552e12541cc0ebf82092be374a9ed2a < 95d064f9828a20ccca5ae90a17be3e2076f25272","Linux >= 051382885552e12541cc0ebf82092be374a9ed2a < 7ff8d6363cffff45654ea85e319f7c0c54226012","Linux >= 051382885552e12541cc0ebf82092be374a9ed2a < 719a10e3f5f868c3c4ac3cf3648c5775d12034bd","Linux >= 051382885552e12541cc0ebf82092be374a9ed2a < 71d068490098b1d23c63b2345e40675d3a1ca763","Linux dcbebc86850324fbe0a993ce352f0539cd98038a","Linux 62980365d6e894234b29f44fb2bfad4f7f8bb824","Linux >= 5.15.154 < 5.16","Linux 6.0"],"published":"2026-09-11","updated":"2026-10-21","sourceUpdated":"2026-10-21T12:48:23.372Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89702","references":[{"url":"https://git.kernel.org/stable/c/1c6a4d6c20fd42552ffc2c3dfaed2139c9477ee5"},{"url":"https://git.kernel.org/stable/c/95d064f9828a20ccca5ae90a17be3e2076f25272"},{"url":"https://git.kernel.org/stable/c/7ff8d6363cffff45654ea85e319f7c0c54226012"},{"url":"https://git.kernel.org/stable/c/719a10e3f5f868c3c4ac3cf3648c5775d12034bd"},{"url":"https://git.kernel.org/stable/c/71d068490098b1d23c63b2345e40675d3a1ca763"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89702.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89702"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532472"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89702"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89702"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89702.mbox"},{"url":"https://kernelcve.org/list/?q=CVE-2026-89702"}],"tags":["cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00457,"epssPercentile":0.39484,"scores":{"cna":9.8,"vendor":7.5},"ingestedAt":"2026-09-14T15:23:07.472Z","slug":"CVE-2026-89702","body":"## Overview\n\nIn 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->rq_xprt->xpt_remotelen)\n            ...\n    )\n    TP_fast_assign(\n            ...\n            __assign_sockaddr(server, &rqstp->rq_xprt->xpt_local,\n                              rqstp->rq_xprt->xpt_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 < 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.\n\n## Affected\n\n- `Linux >= 051382885552e12541cc0ebf82092be374a9ed2a < 1c6a4d6c20fd42552ffc2c3dfaed2139c9477ee5`\n- `Linux >= 051382885552e12541cc0ebf82092be374a9ed2a < 95d064f9828a20ccca5ae90a17be3e2076f25272`\n- `Linux >= 051382885552e12541cc0ebf82092be374a9ed2a < 7ff8d6363cffff45654ea85e319f7c0c54226012`\n- `Linux >= 051382885552e12541cc0ebf82092be374a9ed2a < 719a10e3f5f868c3c4ac3cf3648c5775d12034bd`\n- `Linux >= 051382885552e12541cc0ebf82092be374a9ed2a < 71d068490098b1d23c63b2345e40675d3a1ca763`\n- `Linux dcbebc86850324fbe0a993ce352f0539cd98038a`\n- `Linux 62980365d6e894234b29f44fb2bfad4f7f8bb824`\n- `Linux >= 5.15.154 < 5.16`\n- `Linux 6.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89702.json)","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":227210,"id":"CVE-2026-89702","ts":1792587294846,"field":"cvss","old":"7.5","new":"9.8"},{"seq":227209,"id":"CVE-2026-89702","ts":1792587294846,"field":"severity","old":"high","new":"critical"},{"seq":227011,"id":"CVE-2026-89702","ts":1792584984027,"field":"cvss","old":"9.8","new":"7.5"},{"seq":227010,"id":"CVE-2026-89702","ts":1792584984027,"field":"severity","old":"critical","new":"high"},{"seq":224608,"id":"CVE-2026-89702","ts":1792401434487,"field":"cvss","old":"7","new":"9.8"},{"seq":224607,"id":"CVE-2026-89702","ts":1792401434487,"field":"severity","old":"high","new":"critical"},{"seq":202978,"id":"CVE-2026-89702","ts":1789403733203,"field":"cvss","old":"9.8","new":"7"},{"seq":202977,"id":"CVE-2026-89702","ts":1789403733203,"field":"severity","old":"critical","new":"high"},{"seq":197718,"id":"CVE-2026-89702","ts":1789384318533,"field":"cvss","old":"7","new":"9.8"},{"seq":197717,"id":"CVE-2026-89702","ts":1789384318533,"field":"severity","old":"high","new":"critical"},{"seq":183665,"id":"CVE-2026-89702","ts":1789356676845,"field":"cvss","old":"9.8","new":"7"},{"seq":183664,"id":"CVE-2026-89702","ts":1789356676845,"field":"severity","old":"critical","new":"high"},{"seq":153584,"id":"CVE-2026-89702","ts":1789285351379,"field":"cvss","old":null,"new":"9.8"},{"seq":153583,"id":"CVE-2026-89702","ts":1789285351379,"field":"severity","old":"none","new":"critical"},{"seq":147185,"id":"CVE-2026-89702","ts":1789270199688,"field":"cvss","old":null,"new":"7"},{"seq":147184,"id":"CVE-2026-89702","ts":1789270199688,"field":"severity","old":"none","new":"high"},{"seq":108942,"id":"CVE-2026-89702","ts":1789183729644,"field":"cvss","old":null,"new":"7"},{"seq":108941,"id":"CVE-2026-89702","ts":1789183729644,"field":"severity","old":"none","new":"high"}]}