{"id":"CVE-2026-80561","summary":"libceph: fix multiple unsafe decodes in decode_locker()","details":"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 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   -\u003e ceph_decode_copy_safe\n  *p += sizeof(...)  -\u003e ceph_decode_skip_n\n  ceph_decode_32(p)  -\u003e ceph_decode_32_safe\n  *p += len          -\u003e 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 ]","modified":"2026-08-28T03:47:29.300488918Z","published":"2026-08-26T14:37:26.572Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80561.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1ed45c8d96498725eb54f740172f9068d8673906"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3c3716dc06a34e4ca7f743f5fcfa07fbc5a11070"},{"type":"WEB","url":"https://git.kernel.org/stable/c/437b6551cfcc235eea1d735a874f9d421f555e17"},{"type":"WEB","url":"https://git.kernel.org/stable/c/51c8d238fe7236de627ab1a1433694552a904136"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6265103e78f0ee7e2518de9cf938b94bee9700a0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d1bba38574d095f191557d397d9633f08cd966b1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dbfd83f722a78446ec18a476ef7a38e52240b50a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fa4aa86fff0c56799c2e3f51a88879053285f4a9"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80561.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80561"},{"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":"d4ed4a530562881cc5225050e42d96034f405aae"},{"fixed":"1ed45c8d96498725eb54f740172f9068d8673906"},{"fixed":"6265103e78f0ee7e2518de9cf938b94bee9700a0"},{"fixed":"3c3716dc06a34e4ca7f743f5fcfa07fbc5a11070"},{"fixed":"fa4aa86fff0c56799c2e3f51a88879053285f4a9"},{"fixed":"dbfd83f722a78446ec18a476ef7a38e52240b50a"},{"fixed":"d1bba38574d095f191557d397d9633f08cd966b1"},{"fixed":"51c8d238fe7236de627ab1a1433694552a904136"},{"fixed":"437b6551cfcc235eea1d735a874f9d421f555e17"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80561.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.9.0"},{"fixed":"5.10.266"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.217"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.184"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.153"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.105"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.46"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80561.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}