SEPTEMBER 13, 2026
Live Feed
Back to database
Case File

CVE-2026-89494

CRITICAL · CVSS 9.8 EPSS 0.63%

Source: NVD + CISA KEV + EPSS · Published 2026-09-11 · Last synced 2026-09-13

CyberRota Analysis

AI-Generated

The vulnerability affects the Linux kernel's handling of DLM_MIG_LOCKRES messages, where insufficient validation of peer-supplied fields can lead to out-of-bounds reads and writes. This can result in a system crash (panic) or potential exploitation by any node within the domain, making it critical for environments utilizing the OCFS2 filesystem to prioritize patching. System administrators and security teams managing Linux kernel deployments should address this issue promptly to mitigate risks associated with untrusted message handling.

CVE
CVE-2026-89494
Severity
CRITICAL
CVSS
9.8
EPSS
0.63%
Linux

Original NVD Description

In 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.