{"id":"CVE-2026-80584","title":"s390/qeth: validate user buffer length in SNMP and ARP query ioctls","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/qeth: validate user buffer length in SNMP and ARP query ioctls\n\nqeth_snmp_command() and qeth_l3_arp_query() allocate a buffer sized by\na user-supplied length (udat…","severity":"high","cvss":8.4,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < 9d00eeb2d27f4cc817c5e408760226d43f811ec6","Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < 46443eaddebd84c51940857b11787229be169dec","Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < 91935843f9396a9e45253e2c0d4337ca1371754b","Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < cc423f4105fe145b33e1d7cad34245a798358f73","Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < 3083818e67bcd656965797fbac9a3d6c1d44f78a","Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < a3083647747942ea32faf14560d6397ff3068046","Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < 75fb3151513d7d9f77a8f9545418279b119c06b8","Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < d141f087b1af656f055d7c5793a3e87817ba0bbe","Linux 2.6.26"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T19:17:53.198738Z"},"published":"2026-08-26","updated":"2026-10-16","sourceUpdated":"2026-10-16T19:26:28.329Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80584","references":[{"url":"https://git.kernel.org/stable/c/9d00eeb2d27f4cc817c5e408760226d43f811ec6"},{"url":"https://git.kernel.org/stable/c/46443eaddebd84c51940857b11787229be169dec"},{"url":"https://git.kernel.org/stable/c/91935843f9396a9e45253e2c0d4337ca1371754b"},{"url":"https://git.kernel.org/stable/c/cc423f4105fe145b33e1d7cad34245a798358f73"},{"url":"https://git.kernel.org/stable/c/3083818e67bcd656965797fbac9a3d6c1d44f78a"},{"url":"https://git.kernel.org/stable/c/a3083647747942ea32faf14560d6397ff3068046"},{"url":"https://git.kernel.org/stable/c/75fb3151513d7d9f77a8f9545418279b119c06b8"},{"url":"https://git.kernel.org/stable/c/d141f087b1af656f055d7c5793a3e87817ba0bbe"}],"tags":["cve.org"],"epss":0.00196,"epssPercentile":0.08646,"ingestedAt":"2026-10-16T19:46:24.311Z","slug":"CVE-2026-80584","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ns390/qeth: validate user buffer length in SNMP and ARP query ioctls\n\nqeth_snmp_command() and qeth_l3_arp_query() allocate a buffer sized by\na user-supplied length (udata_len) without checking a lower bound, then\nset udata_offset to a fixed non-zero value and pass both to a reply\ncallback. The callback bounds-checks the copy with\n\n        if ((udata_len - udata_offset) < len)\n\nBoth fields are u32, so a udata_len smaller than udata_offset makes the\nsubtraction wrap and the check pass, and the following memcpy() writes\npast the allocation. A udata_len of 0 also yields ZERO_SIZE_PTR from\nkzalloc(), which the existing NULL check does not catch.\n\nReject buffers smaller than udata_offset before allocating, so the\ncallback subtraction can no longer underflow.\n\n## Affected\n\n- `Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < 9d00eeb2d27f4cc817c5e408760226d43f811ec6`\n- `Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < 46443eaddebd84c51940857b11787229be169dec`\n- `Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < 91935843f9396a9e45253e2c0d4337ca1371754b`\n- `Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < cc423f4105fe145b33e1d7cad34245a798358f73`\n- `Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < 3083818e67bcd656965797fbac9a3d6c1d44f78a`\n- `Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < a3083647747942ea32faf14560d6397ff3068046`\n- `Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < 75fb3151513d7d9f77a8f9545418279b119c06b8`\n- `Linux >= 4a71df50047f0db65ea09b1be155852e81a45eba < d141f087b1af656f055d7c5793a3e87817ba0bbe`\n- `Linux 2.6.26`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":46,"depthScoreParts":{"impact":46.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}