GHSA-HHC4-RPWX-GP2P
Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-14 15:32In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate lengths in dlm_mig_lockres_handler
A node receiving a DLM_MIG_LOCKRES message trusts several fields of the peer-supplied dlm_migratable_lockres without validation. num_locks and lockname_len are bounded only on the sending side, and the message is never checked to actually carry num_locks migratable_lock entries. As a result dlm_process_recovery_data() walks mres->ml[0..num_locks) past the kmalloc(data_len) copy of the message (an out-of-bounds read that ends in a BUG_ON panic), and dlm_init_lockres() copies lockname_len bytes into the fixed 32-byte o2dlm_lockname slab object (a heap out-of-bounds write). Both are reachable by any node in the domain.
Validate these fields right after dlm_grab(), before anything uses them -- including the not-joined error path, which already prints mres->lockname with the unbounded lockname_len as a %.*s precision. Reject the message unless lockname_len <= DLM_LOCKID_NAME_MAX, num_locks <= DLM_MAX_MIGRATABLE_LOCKS (the bound the sender already asserts), and the payload is large enough to hold the claimed locks. Conforming recovery and migration messages are unaffected.
{
"affected": [],
"aliases": [
"CVE-2026-89494"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-11T20:19:31Z",
"severity": "CRITICAL"
},
"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.",
"id": "GHSA-hhc4-rpwx-gp2p",
"modified": "2026-09-14T15:32:27Z",
"published": "2026-09-11T21:31:29Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89494"
},
{
"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"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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