[SRU][Q][PATCH 0/1] CVE-2026-53309

[Cengiz Can]

https://ubuntu.com/security/CVE-2026-53309

[ Impact ]

The ocfs2 DLM code contains an off-by-one error in dlm_match_regions().
When comparing local versus remote regions, the comparison loop uses
'<=' instead of '<', causing it to read one entry past the valid range
of qr_regions. This out-of-bounds read during region matching can lead
to incorrect region validation or a crash, affecting the reliability of
ocfs2 clustered filesystems.

[ Fix ]

questing: clean cherry-pick
focal: clean cherry-pick
bionic: clean cherry-pick
xenial: clean cherry-pick
trusty: clean cherry-pick

[ Test Plan ]

Boot tested.

[ Where Problems Could Occur ]

A regression in this fix would affect the ocfs2/dlm region matching
logic, potentially causing valid regions to be rejected and nodes to
fail joining the DLM domain, which would disrupt ocfs2 cluster mounts.