CVE-2026-53043

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

ocfs2/dlm: validate qr_numregions in dlm_match_regions()

Patch series "ocfs2/dlm: fix two bugs in dlm_match_regions()".

In dlm_match_regions(), the qr_numregions field from a DLM_QUERY_REGION

network message is used to drive loops over the qr_regions buffer without

sufficient validation. This series fixes two issues:

- Patch 1 adds a bounds check to reject messages where qr_numregions

exceeds O2NM_MAX_REGIONS. The o2net layer only validates message

byte length; it does not constrain field values, so a crafted message

can set qr_numregions up to 255 and trigger out-of-bounds reads past

the 1024-byte qr_regions buffer.

- Patch 2 fixes an off-by-one in the local-vs-remote comparison loop,

which uses '<=' instead of '<', reading one entry past the valid range

even when qr_numregions is within bounds.

This patch (of 2):

The qr_numregions field from a DLM_QUERY_REGION network message is used

directly as

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References