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.

Project Subscriptions

Vendors Products
Linux Kernel Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Sat, 12 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-787
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.6, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Important


Fri, 11 Sep 2026 23:45:00 +0000

Type Values Removed Values Added
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.
Title ocfs2: validate lengths in dlm_mig_lockres_handler
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-11T19:43:45.455Z

Reserved: 2026-09-11T19:38:34.714Z

Link: CVE-2026-89494

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-11T20:19:31.370

Modified: 2026-09-11T20:19:31.370

Link: CVE-2026-89494

cve-icon Redhat

Severity : Important

Publid Date: 2026-09-11T19:43:45Z

Links: CVE-2026-89494 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses