{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-53043: ocfs2/dlm: validate qr_numregions in dlm_match_regions()","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-53043","status":"final","version":"1","initial_release_date":"2026-06-24T16:29:49.480Z","current_release_date":"2026-06-28T06:38:24.551Z","revision_history":[{"date":"2026-06-24T16:29:49.480Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2/dlm: validate qr_numregions in dlm_match_regions()\n\nPatch series \"ocfs2/dlm: fix two bugs in dlm_match_regions()\".\n\nIn dlm_match_regions(), the qr_numregions field from a DLM_QUERY_REGION\nnetwork message is used to drive loops over the qr_regions buffer without\nsufficient validation.  This series fixes two issues:\n\n- Patch 1 adds a bounds check to reject messages where qr_numregions\n  exceeds O2NM_MAX_REGIONS. The o2net layer only validates message\n  byte length; it does not constrain field values, so a crafted message\n  can set qr_numregions up to 255 and trigger out-of-bounds reads past\n  the 1024-byte qr_regions buffer.\n\n- Patch 2 fixes an off-by-one in the local-vs-remote comparison loop,\n  which uses '<=' instead of '<', reading one entry past the valid range\n  even when qr_numregions is within bounds.\n\n\nThis patch (of 2):\n\nThe qr_numregions field from a DLM_QUERY_REGION network message is used\ndirectly as loop bounds in dlm_match_regions() without checking against\nO2NM_MAX_REGIONS.  Since qr_regions is sized for at most O2NM_MAX_REGIONS\n(32) entries, a crafted message with qr_numregions > 32 causes\nout-of-bounds reads past the qr_regions buffer.\n\nAdd a bounds check for qr_numregions before entering the loops.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-53043 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-53043"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-53043"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/d3d5efade0c79dac1cac98c0cb1115432f804439"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/f69551139caf6d24242a0ad049ee46b264e3aee0"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/1f8b91275912cd428289c1fb424bebd7ff5302bd"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/f37de46149db49abd2b24f4f0c5a88cf4dfb5f47"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/6c6e8fc3c007319981647b410c29bb5775048551"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/3f474c33ebc2e2ca3fcb587d7de4375348f13373"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/3c2d0de23ae4be22b6c18e8f0915be74d3b5fb21"},{"category":"external","summary":"git.kernel.org","url":"https://git.kernel.org/stable/c/7ab3fbb01bc6d79091bc375e5235d360cd9b78be"}]},"product_tree":{"branches":[{"category":"vendor","name":"Linux","branches":[{"category":"product_name","name":"Linux","branches":[{"category":"product_version_range","name":">=ea2034416b54700e30371f2ad6517cbb94674083 <d3d5efade0c79dac1cac98c0cb1115432f804439","product":{"name":"Linux Linux >=ea2034416b54700e30371f2ad6517cbb94674083 <d3d5efade0c79dac1cac98c0cb1115432f804439","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=ea2034416b54700e30371f2ad6517cbb94674083 <f69551139caf6d24242a0ad049ee46b264e3aee0","product":{"name":"Linux Linux >=ea2034416b54700e30371f2ad6517cbb94674083 <f69551139caf6d24242a0ad049ee46b264e3aee0","product_id":"CSAFPID-2","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=ea2034416b54700e30371f2ad6517cbb94674083 <1f8b91275912cd428289c1fb424bebd7ff5302bd","product":{"name":"Linux Linux >=ea2034416b54700e30371f2ad6517cbb94674083 <1f8b91275912cd428289c1fb424bebd7ff5302bd","product_id":"CSAFPID-3","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=ea2034416b54700e30371f2ad6517cbb94674083 <f37de46149db49abd2b24f4f0c5a88cf4dfb5f47","product":{"name":"Linux Linux >=ea2034416b54700e30371f2ad6517cbb94674083 <f37de46149db49abd2b24f4f0c5a88cf4dfb5f47","product_id":"CSAFPID-4","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=ea2034416b54700e30371f2ad6517cbb94674083 <6c6e8fc3c007319981647b410c29bb5775048551","product":{"name":"Linux Linux >=ea2034416b54700e30371f2ad6517cbb94674083 <6c6e8fc3c007319981647b410c29bb5775048551","product_id":"CSAFPID-5","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=ea2034416b54700e30371f2ad6517cbb94674083 <3f474c33ebc2e2ca3fcb587d7de4375348f13373","product":{"name":"Linux Linux >=ea2034416b54700e30371f2ad6517cbb94674083 <3f474c33ebc2e2ca3fcb587d7de4375348f13373","product_id":"CSAFPID-6","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=ea2034416b54700e30371f2ad6517cbb94674083 <3c2d0de23ae4be22b6c18e8f0915be74d3b5fb21","product":{"name":"Linux Linux >=ea2034416b54700e30371f2ad6517cbb94674083 <3c2d0de23ae4be22b6c18e8f0915be74d3b5fb21","product_id":"CSAFPID-7","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=ea2034416b54700e30371f2ad6517cbb94674083 <7ab3fbb01bc6d79091bc375e5235d360cd9b78be","product":{"name":"Linux Linux >=ea2034416b54700e30371f2ad6517cbb94674083 <7ab3fbb01bc6d79091bc375e5235d360cd9b78be","product_id":"CSAFPID-8","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*"}}}]}]},{"category":"vendor","name":"Linux","branches":[{"category":"product_name","name":"Linux","branches":[{"category":"product_version","name":"2.6.37","product":{"name":"Linux Linux 2.6.37","product_id":"CSAFPID-9","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:2.6.37:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"0","product":{"name":"Linux Linux 0","product_id":"CSAFPID-10","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:2.6.37:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"5.10.258","product":{"name":"Linux Linux 5.10.258","product_id":"CSAFPID-11","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:2.6.37:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"5.15.209","product":{"name":"Linux Linux 5.15.209","product_id":"CSAFPID-12","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:2.6.37:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"6.1.175","product":{"name":"Linux Linux 6.1.175","product_id":"CSAFPID-13","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:2.6.37:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"6.6.141","product":{"name":"Linux Linux 6.6.141","product_id":"CSAFPID-14","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:2.6.37:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"6.12.91","product":{"name":"Linux Linux 6.12.91","product_id":"CSAFPID-15","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:2.6.37:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"6.18.33","product":{"name":"Linux Linux 6.18.33","product_id":"CSAFPID-16","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:2.6.37:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"7.0.10","product":{"name":"Linux Linux 7.0.10","product_id":"CSAFPID-17","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:2.6.37:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"7.1","product":{"name":"Linux Linux 7.1","product_id":"CSAFPID-18","product_identification_helper":{"cpe":"cpe:2.3:a:linux:linux:2.6.37:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-53043","title":"ocfs2/dlm: validate qr_numregions in dlm_match_regions()","notes":[{"category":"description","text":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2/dlm: validate qr_numregions in dlm_match_regions()\n\nPatch series \"ocfs2/dlm: fix two bugs in dlm_match_regions()\".\n\nIn dlm_match_regions(), the qr_numregions field from a DLM_QUERY_REGION\nnetwork message is used to drive loops over the qr_regions buffer without\nsufficient validation.  This series fixes two issues:\n\n- Patch 1 adds a bounds check to reject messages where qr_numregions\n  exceeds O2NM_MAX_REGIONS. The o2net layer only validates message\n  byte length; it does not constrain field values, so a crafted message\n  can set qr_numregions up to 255 and trigger out-of-bounds reads past\n  the 1024-byte qr_regions buffer.\n\n- Patch 2 fixes an off-by-one in the local-vs-remote comparison loop,\n  which uses '<=' instead of '<', reading one entry past the valid range\n  even when qr_numregions is within bounds.\n\n\nThis patch (of 2):\n\nThe qr_numregions field from a DLM_QUERY_REGION network message is used\ndirectly as loop bounds in dlm_match_regions() without checking against\nO2NM_MAX_REGIONS.  Since qr_regions is sized for at most O2NM_MAX_REGIONS\n(32) entries, a crafted message with qr_numregions > 32 causes\nout-of-bounds reads past the qr_regions buffer.\n\nAdd a bounds check for qr_numregions before entering the loops.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1","CSAFPID-2","CSAFPID-3","CSAFPID-4","CSAFPID-5","CSAFPID-6","CSAFPID-7","CSAFPID-8","CSAFPID-9"],"fixed":["CSAFPID-10","CSAFPID-11","CSAFPID-12","CSAFPID-13","CSAFPID-14","CSAFPID-15","CSAFPID-16","CSAFPID-17","CSAFPID-18"]},"scores":[{"cvss_v3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","baseScore":9.1,"baseSeverity":"CRITICAL"},"products":["CSAFPID-1","CSAFPID-2","CSAFPID-3","CSAFPID-4","CSAFPID-5","CSAFPID-6","CSAFPID-7","CSAFPID-8","CSAFPID-9"]}],"remediations":[{"category":"vendor_fix","details":"Update to a fixed version: 0, 1f8b91275912cd428289c1fb424bebd7ff5302bd, 3c2d0de23ae4be22b6c18e8f0915be74d3b5fb21, 3f474c33ebc2e2ca3fcb587d7de4375348f13373, 5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33, 6c6e8fc3c007319981647b410c29bb5775048551, 7.0.10, 7.1, 7ab3fbb01bc6d79091bc375e5235d360cd9b78be, d3d5efade0c79dac1cac98c0cb1115432f804439, f37de46149db49abd2b24f4f0c5a88cf4dfb5f47, f69551139caf6d24242a0ad049ee46b264e3aee0.","product_ids":["CSAFPID-1","CSAFPID-2","CSAFPID-3","CSAFPID-4","CSAFPID-5","CSAFPID-6","CSAFPID-7","CSAFPID-8","CSAFPID-9"]}]}]}