{"id":"CVE-2026-89494","summary":"ocfs2: validate lengths in dlm_mig_lockres_handler","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: validate lengths in dlm_mig_lockres_handler\n\nA node receiving a DLM_MIG_LOCKRES message trusts several fields of the\npeer-supplied dlm_migratable_lockres without validation.  num_locks and\nlockname_len are bounded only on the sending side, and the message is\nnever checked to actually carry num_locks migratable_lock entries.  As a\nresult dlm_process_recovery_data() walks mres-\u003eml[0..num_locks) past the\nkmalloc(data_len) copy of the message (an out-of-bounds read that ends in\na BUG_ON panic), and dlm_init_lockres() copies lockname_len bytes into the\nfixed 32-byte o2dlm_lockname slab object (a heap out-of-bounds write). \nBoth are reachable by any node in the domain.\n\nValidate these fields right after dlm_grab(), before anything uses them --\nincluding the not-joined error path, which already prints mres-\u003elockname\nwith the unbounded lockname_len as a %.*s precision.  Reject the message\nunless lockname_len \u003c= DLM_LOCKID_NAME_MAX, num_locks \u003c=\nDLM_MAX_MIGRATABLE_LOCKS (the bound the sender already asserts), and the\npayload is large enough to hold the claimed locks.  Conforming recovery\nand migration messages are unaffected.","modified":"2026-09-15T03:48:19.613793343Z","published":"2026-09-11T19:43:45.455Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89494.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0e999d56917f861f97adb961617b1828c9eb4733"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4a5798253212093b9ff7d90c6cfbe348bcda1594"},{"type":"WEB","url":"https://git.kernel.org/stable/c/50c4cc9183e11f83427efbf770f54851f4471c02"},{"type":"WEB","url":"https://git.kernel.org/stable/c/77686fa5bba135252d348e2dacf481fc19f60c41"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a8facb1670b4a0612183198e758d9539ef628ed9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b54e03d9b3697d25f4a0063cf717d459c5e3ad94"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dce05b17db862f47ff60614017abe639b2e71cad"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f33041906885f96e190cde54e61ddc69de39e3ee"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89494.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89494"},{"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":"6714d8e86bf443f6f7af50f9d432025649f091f5"},{"fixed":"4a5798253212093b9ff7d90c6cfbe348bcda1594"},{"fixed":"dce05b17db862f47ff60614017abe639b2e71cad"},{"fixed":"0e999d56917f861f97adb961617b1828c9eb4733"},{"fixed":"77686fa5bba135252d348e2dacf481fc19f60c41"},{"fixed":"f33041906885f96e190cde54e61ddc69de39e3ee"},{"fixed":"50c4cc9183e11f83427efbf770f54851f4471c02"},{"fixed":"a8facb1670b4a0612183198e758d9539ef628ed9"},{"fixed":"b54e03d9b3697d25f4a0063cf717d459c5e3ad94"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89494.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.16"},{"fixed":"5.10.270"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.221"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.188"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.109"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.50"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89494.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"}]}