CVE-2026-53043: ocfs2/dlm: validate qr_numregions in dlm_match_regions()
In the Linux kernel, the following vulnerability has been resolved:
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.176-1Fixed in 6.1.187-1Fixed in 6.12.94-1Fixed in 6.12.107-1Fixed in 7.1.12-1Fixed in 7.1.13-1 - Upgrade
Upgrade
Linux kernel ocfs2/dlmto a version that resolves this vulnerability.Patch ocfs2/dlm: fix two bugs in dlm_match_regions() - Configuration
In dlm_match_regions(), validate the qr_numregions field from DLM_QUERY_REGION network messages and reject the message when qr_numregions exceeds O2NM_MAX_REGIONS (32), before using it as loop bounds over the qr_regions buffer.
ocfs2/dlm (dlm_match_regions) qr_numregions validation against O2NM_MAX_REGIONS = reject if qr_numregions exceeds O2NM_MAX_REGIONS - Configuration
In dlm_match_regions(), fix the off-by-one in the local-vs-remote comparison loop by changing the loop condition from '<=' to '<' so it does not read one entry past the valid range.
ocfs2/dlm (dlm_match_regions) local-vs-remote comparison loop bounds operator = use '<' instead of '<='
Event History
Frequently Asked Questions
What is the severity of CVE-2026-53043?
CVE-2026-53043 has been rated with a critical severity score of 9.1.
How do I fix CVE-2026-53043?
To mitigate CVE-2026-53043, you should update your Linux kernel to the latest patched version that resolves the vulnerability.
What are the potential impacts of CVE-2026-53043?
CVE-2026-53043 could lead to denial of service conditions due to improper validation in the kernel's DLM component.
Which software is affected by CVE-2026-53043?
CVE-2026-53043 specifically affects the Linux kernel and the OCFS2 DLM subsystem.
What is the nature of CVE-2026-53043?
CVE-2026-53043 is a vulnerability that involves insufficient validation of the qr_numregions field in the dlm_match_regions function.