GHSA-HV9W-QQH8-9PFH
Vulnerability from github – Published: 2026-06-24 18:32 – Updated: 2026-06-28 09:31In 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": [],
"aliases": [
"CVE-2026-53043"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-24T17:17:16Z",
"severity": "CRITICAL"
},
"details": "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 \u0027\u003c=\u0027 instead of \u0027\u003c\u0027, 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 \u003e 32 causes\nout-of-bounds reads past the qr_regions buffer.\n\nAdd a bounds check for qr_numregions before entering the loops.",
"id": "GHSA-hv9w-qqh8-9pfh",
"modified": "2026-06-28T09:31:39Z",
"published": "2026-06-24T18:32:45Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53043"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1f8b91275912cd428289c1fb424bebd7ff5302bd"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3c2d0de23ae4be22b6c18e8f0915be74d3b5fb21"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3f474c33ebc2e2ca3fcb587d7de4375348f13373"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6c6e8fc3c007319981647b410c29bb5775048551"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7ab3fbb01bc6d79091bc375e5235d360cd9b78be"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d3d5efade0c79dac1cac98c0cb1115432f804439"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f37de46149db49abd2b24f4f0c5a88cf4dfb5f47"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f69551139caf6d24242a0ad049ee46b264e3aee0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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