{"id":"CVE-2026-80561","title":"libceph: fix multiple unsafe decodes in decode_locker()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: fix multiple unsafe decodes in decode_locker()\n\ndecode_locker() in cls_lock_client.c contains three unsafe decode\noperations that allow a malicious or compromi…","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","vendor":"Linux","product":"Linux","affected":["Linux >= d4ed4a530562881cc5225050e42d96034f405aae < 1ed45c8d96498725eb54f740172f9068d8673906","Linux >= d4ed4a530562881cc5225050e42d96034f405aae < 6265103e78f0ee7e2518de9cf938b94bee9700a0","Linux >= d4ed4a530562881cc5225050e42d96034f405aae < 3c3716dc06a34e4ca7f743f5fcfa07fbc5a11070","Linux >= d4ed4a530562881cc5225050e42d96034f405aae < fa4aa86fff0c56799c2e3f51a88879053285f4a9","Linux >= d4ed4a530562881cc5225050e42d96034f405aae < dbfd83f722a78446ec18a476ef7a38e52240b50a","Linux >= d4ed4a530562881cc5225050e42d96034f405aae < d1bba38574d095f191557d397d9633f08cd966b1","Linux >= d4ed4a530562881cc5225050e42d96034f405aae < 51c8d238fe7236de627ab1a1433694552a904136","Linux >= d4ed4a530562881cc5225050e42d96034f405aae < 437b6551cfcc235eea1d735a874f9d421f555e17","Linux 4.9"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T19:17:30.394724Z"},"published":"2026-08-26","updated":"2026-10-16","sourceUpdated":"2026-10-16T19:26:27.238Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80561","references":[{"url":"https://git.kernel.org/stable/c/1ed45c8d96498725eb54f740172f9068d8673906"},{"url":"https://git.kernel.org/stable/c/6265103e78f0ee7e2518de9cf938b94bee9700a0"},{"url":"https://git.kernel.org/stable/c/3c3716dc06a34e4ca7f743f5fcfa07fbc5a11070"},{"url":"https://git.kernel.org/stable/c/fa4aa86fff0c56799c2e3f51a88879053285f4a9"},{"url":"https://git.kernel.org/stable/c/dbfd83f722a78446ec18a476ef7a38e52240b50a"},{"url":"https://git.kernel.org/stable/c/d1bba38574d095f191557d397d9633f08cd966b1"},{"url":"https://git.kernel.org/stable/c/51c8d238fe7236de627ab1a1433694552a904136"},{"url":"https://git.kernel.org/stable/c/437b6551cfcc235eea1d735a874f9d421f555e17"}],"tags":["cve.org"],"epss":0.00514,"epssPercentile":0.42522,"ingestedAt":"2026-10-16T19:46:24.314Z","slug":"CVE-2026-80561","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: fix multiple unsafe decodes in decode_locker()\n\ndecode_locker() in cls_lock_client.c contains three unsafe decode\noperations that allow a malicious or compromised OSD to trigger\nslab-out-of-bounds reads:\n\n1. ceph_decode_copy() at the locker_id_t name field has no preceding\n   bounds check. With p == end after ceph_start_decoding() accepts\n   struct_len=0, this reads sizeof(ceph_entity_name) = 9 bytes past\n   the validated buffer boundary.\n\n2. *p += sizeof(struct ceph_timespec) after the locker_info_t header\n   is an unchecked pointer advance. A malicious OSD can position p\n   past end, causing all subsequent _safe checks to pass against a\n   bogus boundary.\n\n3. len = ceph_decode_32(p) has no preceding bounds check, and the\n   immediately following *p += len is uncapped. A malicious OSD can\n   send len=0xffffffff, advancing p gigabytes past end and escaping\n   the decode window entirely.\n\nFix all three by replacing bare operations with their safe variants:\n  ceph_decode_copy   -> ceph_decode_copy_safe\n  *p += sizeof(...)  -> ceph_decode_skip_n\n  ceph_decode_32(p)  -> ceph_decode_32_safe\n  *p += len          -> ceph_decode_skip_n\n\nA new label is added to return -EINVAL on any bounds violation.\n-EINVAL is appropriate here: the data received from the OSD\nis structurally malformed, which is an invalid argument to the decode\ncontract regardless of whether the caller or the wire is at fault.\n\nAttacker model: a malicious or compromised OSD in a multi-tenant Ceph\ndeployment can trigger this against any kernel client that issues the\nlock.get_info class method (e.g. during RBD exclusive lock acquisition)\nwithout any further privileges beyond OSD session establishment.\n\n[ idryomov: use ceph_decode_skip_string() to skip description, trim\n  changelog ]\n\n## Affected\n\n- `Linux >= d4ed4a530562881cc5225050e42d96034f405aae < 1ed45c8d96498725eb54f740172f9068d8673906`\n- `Linux >= d4ed4a530562881cc5225050e42d96034f405aae < 6265103e78f0ee7e2518de9cf938b94bee9700a0`\n- `Linux >= d4ed4a530562881cc5225050e42d96034f405aae < 3c3716dc06a34e4ca7f743f5fcfa07fbc5a11070`\n- `Linux >= d4ed4a530562881cc5225050e42d96034f405aae < fa4aa86fff0c56799c2e3f51a88879053285f4a9`\n- `Linux >= d4ed4a530562881cc5225050e42d96034f405aae < dbfd83f722a78446ec18a476ef7a38e52240b50a`\n- `Linux >= d4ed4a530562881cc5225050e42d96034f405aae < d1bba38574d095f191557d397d9633f08cd966b1`\n- `Linux >= d4ed4a530562881cc5225050e42d96034f405aae < 51c8d238fe7236de627ab1a1433694552a904136`\n- `Linux >= d4ed4a530562881cc5225050e42d96034f405aae < 437b6551cfcc235eea1d735a874f9d421f555e17`\n- `Linux 4.9`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}