{"id":"CVE-2026-89665","title":"nfsd: reject out-of-range useconds in NFSv2 SETATTR/CREATE","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: reject out-of-range useconds in NFSv2 SETATTR/CREATE\n\nThe NFSv2 sattr decoder converts the wire useconds to nanoseconds in\nsvcxdr_decode_sattr():\n\n\tiap->ia_atime.…","severity":"high","cvss":8.2,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L","cvssSource":"cna","cwe":["CWE-190"],"vendor":"Linux","product":"Linux","affected":["Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < cdc3299f7072777b09c9582a3b8b65bb163ddcf3","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 09a79d9ab35a39603c834e8f6333603292f9c816","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 5296a2442d12d45d6eea7b4d3ec3ffecc1821cac","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1db456ffc22e045f49f7b9e62415a26b3f33f200","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a937dd1aa2d92291fe0a1860d17e90d8f206cd22","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < ad02d095439f89cbd6629420c7e3ba476457b83b","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1195483965a5f63d2dde18054ec7e50a23b9071c","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 26709c8ffe73772eb69e68d553ac71d91228dccc","Linux 2.6.12"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-10-16T19:25:40.808424Z"},"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:50:36.772Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89665","references":[{"url":"https://git.kernel.org/stable/c/cdc3299f7072777b09c9582a3b8b65bb163ddcf3"},{"url":"https://git.kernel.org/stable/c/09a79d9ab35a39603c834e8f6333603292f9c816"},{"url":"https://git.kernel.org/stable/c/5296a2442d12d45d6eea7b4d3ec3ffecc1821cac"},{"url":"https://git.kernel.org/stable/c/1db456ffc22e045f49f7b9e62415a26b3f33f200"},{"url":"https://git.kernel.org/stable/c/a937dd1aa2d92291fe0a1860d17e90d8f206cd22"},{"url":"https://git.kernel.org/stable/c/ad02d095439f89cbd6629420c7e3ba476457b83b"},{"url":"https://git.kernel.org/stable/c/1195483965a5f63d2dde18054ec7e50a23b9071c"},{"url":"https://git.kernel.org/stable/c/26709c8ffe73772eb69e68d553ac71d91228dccc"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89665.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89665"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532498"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89665"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89665"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89665.mbox"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.00621,"epssPercentile":0.49548,"scores":{"cna":8.2,"vendor":7},"ingestedAt":"2026-09-14T15:23:07.450Z","slug":"CVE-2026-89665","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: reject out-of-range useconds in NFSv2 SETATTR/CREATE\n\nThe NFSv2 sattr decoder converts the wire useconds to nanoseconds in\nsvcxdr_decode_sattr():\n\n\tiap->ia_atime.tv_nsec = tmp2 * NSEC_PER_USEC;\n\ntmp2 is a u32 and NSEC_PER_USEC is 1000, so the product is computed in\nunsigned long. On ILP32 that is 32 bits, and an out-of-range useconds\nvalue such as 4294968 wraps to tv_nsec == 704. The corruption therefore\nhappens during decode, before any proc function can inspect the value,\nand a later range check on tv_nsec would see an in-range result and\naccept it. Rejecting in the decoder yields an RPC GARBAGE_ARGS reply.\nNFSv2 defines no NFSERR_INVAL, so there is no NFS-level status to return\nfor a malformed time argument, and the check cannot move to the proc\nfunction the way the v3/v4 nsec range checks do.\n\nGuard the raw useconds before the multiplication and reject values\ngreater than 1000000. useconds == 1000000 is kept: it is the Sun\nconvention for \"set to the current server time\", and the in-tree Linux\nNFSv2 client emits it in both the atime and the mtime field for a plain\ntouch / utimes(file, NULL) (see encode_sattr() and\nxdr_encode_current_server_time() in fs/nfs/nfs2xdr.c). Rejecting 1000000\nwould turn that common operation into a hard decode failure for both\nSETATTR and CREATE. 1000000 * NSEC_PER_USEC is 10^9, which does not wrap\non ILP32, so the Sun convention value passes through safely. Only\ngenuinely out-of-range values (> 1000000) are rejected. The atime and\nmtime guards are therefore symmetric.\n\nThe decoder only applied the Sun convention in the mtime block, which\nclears ATTR_ATIME_SET|ATTR_MTIME_SET when mtime useconds == 1000000. If a\nclient puts 1000000 in the atime field but not in the mtime field, the\natime block stored an out-of-range tv_nsec (10^9) and left ATTR_ATIME_SET\nset, so the bogus value reached the filesystem. Apply the convention in\nthe atime block as well, clearing ATTR_ATIME_SET so the server uses its\ncurrent time and ignores the value. Only ATTR_ATIME_SET is cleared there.\nThe mtime block keeps its existing behavior, where 1000000 means \"set\nboth atime and mtime to now\".\n\n[ cel: various tweaks, addenda, and clean-ups ]\n\n## Affected\n\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < cdc3299f7072777b09c9582a3b8b65bb163ddcf3`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 09a79d9ab35a39603c834e8f6333603292f9c816`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 5296a2442d12d45d6eea7b4d3ec3ffecc1821cac`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1db456ffc22e045f49f7b9e62415a26b3f33f200`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a937dd1aa2d92291fe0a1860d17e90d8f206cd22`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < ad02d095439f89cbd6629420c7e3ba476457b83b`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1195483965a5f63d2dde18054ec7e50a23b9071c`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 26709c8ffe73772eb69e68d553ac71d91228dccc`\n- `Linux 2.6.12`\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 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat OpenShift Container Platform 4 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89665.json)","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":45.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":223253,"id":"CVE-2026-89665","ts":1792180032112,"field":"cvss","old":"7","new":"8.2"},{"seq":203966,"id":"CVE-2026-89665","ts":1789490230835,"field":"cvss","old":"8.2","new":"7"},{"seq":197775,"id":"CVE-2026-89665","ts":1789384318796,"field":"cvss","old":"6.8","new":"8.2"},{"seq":197774,"id":"CVE-2026-89665","ts":1789384318796,"field":"severity","old":"medium","new":"high"},{"seq":183696,"id":"CVE-2026-89665","ts":1789356676993,"field":"cvss","old":"8.2","new":"6.8"},{"seq":183695,"id":"CVE-2026-89665","ts":1789356676993,"field":"severity","old":"high","new":"medium"},{"seq":153526,"id":"CVE-2026-89665","ts":1789285351150,"field":"cvss","old":null,"new":"8.2"},{"seq":153525,"id":"CVE-2026-89665","ts":1789285351150,"field":"severity","old":"none","new":"high"},{"seq":147163,"id":"CVE-2026-89665","ts":1789270198036,"field":"cvss","old":null,"new":"6.8"},{"seq":147162,"id":"CVE-2026-89665","ts":1789270198036,"field":"severity","old":"none","new":"medium"},{"seq":108912,"id":"CVE-2026-89665","ts":1789183729512,"field":"cvss","old":null,"new":"6.8"},{"seq":108911,"id":"CVE-2026-89665","ts":1789183729512,"field":"severity","old":"none","new":"medium"}]}