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CVE PROGRAM SOURCE RECORD9.1 Critical

CVE-2026-53043

ocfs2/dlm: validate qr_numregions in dlm_match_regions()

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 loop bounds in dlm_match_regions() without checking against O2NM_MAX_REGIONS. Since qr_regions is sized for at most O2NM_MAX_REGIONS (32) entries, a crafted message with qr_numregions > 32 causes out-of-bounds reads past the qr_regions buffer. Add a bounds check for qr_numregions before entering the loops.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • ea2034416b54700e30371f2ad6517cbb94674083 to < d3d5efade0c79dac1cac98c0cb1115432f804439affected
  • ea2034416b54700e30371f2ad6517cbb94674083 to < f69551139caf6d24242a0ad049ee46b264e3aee0affected
  • ea2034416b54700e30371f2ad6517cbb94674083 to < 1f8b91275912cd428289c1fb424bebd7ff5302bdaffected
  • ea2034416b54700e30371f2ad6517cbb94674083 to < f37de46149db49abd2b24f4f0c5a88cf4dfb5f47affected
  • ea2034416b54700e30371f2ad6517cbb94674083 to < 6c6e8fc3c007319981647b410c29bb5775048551affected
  • ea2034416b54700e30371f2ad6517cbb94674083 to < 3f474c33ebc2e2ca3fcb587d7de4375348f13373affected
  • ea2034416b54700e30371f2ad6517cbb94674083 to < 3c2d0de23ae4be22b6c18e8f0915be74d3b5fb21affected
  • ea2034416b54700e30371f2ad6517cbb94674083 to < 7ab3fbb01bc6d79091bc375e5235d360cd9b78beaffected

Linux Linux

Default version status: affected

  • 2.6.37affected
  • 0 to < 2.6.37unaffected
  • 5.10.258 to ≤ 5.10.*unaffected
  • 5.15.209 to ≤ 5.15.*unaffected
  • 6.1.175 to ≤ 6.1.*unaffected
  • 6.6.141 to ≤ 6.6.*unaffected
  • 6.12.91 to ≤ 6.12.*unaffected
  • 6.18.33 to ≤ 6.18.*unaffected
  • 7.0.10 to ≤ 7.0.*unaffected
  • 7.1 to ≤ *unaffected

References