{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-53043", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-06-09T07:44:35.380Z", "datePublished": "2026-06-24T16:29:49.480Z", "dateUpdated": "2026-08-05T12:32:50.728Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:32:50.728Z" }, "descriptions": [ { "lang": "en", "value": "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." } ], "metrics": [ { "cvssV3_1": { "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" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable `DLM_QUERY_REGION` message is received over OCFS2 o2net TCP connections from cluster peers, so the code is reachable via network protocol traffic.\nAC:L - A malicious configured/heartbeating peer can create the DLM join state and send a crafted `qr_numregions` value; no race or condition outside the attacker's control is required once the cluster service is exposed.\nPR:N - The receiver performs cluster IP/heartbeat gating but no user authentication or target-local privilege check before dispatching the DLM message, so exploitation does not require an account or privileges on the victim.\nUI:N - No victim user action is needed after the OCFS2 cluster/DLM service is running; the attacker sends network messages.\nS:U - The impact remains within the kernel/OCFS2 cluster node security authority and does not cross a separate boundary such as guest-to-host or IOMMU isolation.\nC:H - The attacker-controlled count drives out-of-bounds reads past the fixed `qr_regions` buffer into adjacent kernel memory; under the higher-severity rule, this is a high confidentiality impact.\nI:N - The vulnerable loops perform reads and comparisons/logging only, with no out-of-bounds write or demonstrated control-flow/data modification primitive.\nA:H - The crafted message can force kernel out-of-bounds memory reads from the receive buffer path and can reasonably cause an oops/crash or repeated DLM join failure, so availability impact is high." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ocfs2/dlm/dlmdomain.c" ], "versions": [ { "version": "ea2034416b54700e30371f2ad6517cbb94674083", "lessThan": "d3d5efade0c79dac1cac98c0cb1115432f804439", "status": "affected", "versionType": "git" }, { "version": "ea2034416b54700e30371f2ad6517cbb94674083", "lessThan": "f69551139caf6d24242a0ad049ee46b264e3aee0", "status": "affected", "versionType": "git" }, { "version": "ea2034416b54700e30371f2ad6517cbb94674083", "lessThan": "1f8b91275912cd428289c1fb424bebd7ff5302bd", "status": "affected", "versionType": "git" }, { "version": "ea2034416b54700e30371f2ad6517cbb94674083", "lessThan": "f37de46149db49abd2b24f4f0c5a88cf4dfb5f47", "status": "affected", "versionType": "git" }, { "version": "ea2034416b54700e30371f2ad6517cbb94674083", "lessThan": "6c6e8fc3c007319981647b410c29bb5775048551", "status": "affected", "versionType": "git" }, { "version": "ea2034416b54700e30371f2ad6517cbb94674083", "lessThan": "3f474c33ebc2e2ca3fcb587d7de4375348f13373", "status": "affected", "versionType": "git" }, { "version": "ea2034416b54700e30371f2ad6517cbb94674083", "lessThan": "3c2d0de23ae4be22b6c18e8f0915be74d3b5fb21", "status": "affected", "versionType": "git" }, { "version": "ea2034416b54700e30371f2ad6517cbb94674083", "lessThan": "7ab3fbb01bc6d79091bc375e5235d360cd9b78be", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ocfs2/dlm/dlmdomain.c" ], "versions": [ { "version": "2.6.37", "status": "affected" }, { "version": "0", "lessThan": "2.6.37", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.258", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.209", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.141", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.91", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.33", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.10", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "5.10.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.6.141" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.12.91" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.18.33" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "7.0.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/d3d5efade0c79dac1cac98c0cb1115432f804439" }, { "url": "https://git.kernel.org/stable/c/f69551139caf6d24242a0ad049ee46b264e3aee0" }, { "url": "https://git.kernel.org/stable/c/1f8b91275912cd428289c1fb424bebd7ff5302bd" }, { "url": "https://git.kernel.org/stable/c/f37de46149db49abd2b24f4f0c5a88cf4dfb5f47" }, { "url": "https://git.kernel.org/stable/c/6c6e8fc3c007319981647b410c29bb5775048551" }, { "url": "https://git.kernel.org/stable/c/3f474c33ebc2e2ca3fcb587d7de4375348f13373" }, { "url": "https://git.kernel.org/stable/c/3c2d0de23ae4be22b6c18e8f0915be74d3b5fb21" }, { "url": "https://git.kernel.org/stable/c/7ab3fbb01bc6d79091bc375e5235d360cd9b78be" } ], "title": "ocfs2/dlm: validate qr_numregions in dlm_match_regions()", "x_generator": { "engine": "bippy-1.2.0" } } } }