{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89494", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.714Z", "datePublished": "2026-09-11T19:43:45.455Z", "dateUpdated": "2026-10-19T08:47:45.937Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:47:45.937Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: validate lengths in dlm_mig_lockres_handler\n\nA node receiving a DLM_MIG_LOCKRES message trusts several fields of the\npeer-supplied dlm_migratable_lockres without validation. num_locks and\nlockname_len are bounded only on the sending side, and the message is\nnever checked to actually carry num_locks migratable_lock entries. As a\nresult dlm_process_recovery_data() walks mres->ml[0..num_locks) past the\nkmalloc(data_len) copy of the message (an out-of-bounds read that ends in\na BUG_ON panic), and dlm_init_lockres() copies lockname_len bytes into the\nfixed 32-byte o2dlm_lockname slab object (a heap out-of-bounds write). \nBoth are reachable by any node in the domain.\n\nValidate these fields right after dlm_grab(), before anything uses them --\nincluding the not-joined error path, which already prints mres->lockname\nwith the unbounded lockname_len as a %.*s precision. Reject the message\nunless lockname_len <= DLM_LOCKID_NAME_MAX, num_locks <=\nDLM_MAX_MIGRATABLE_LOCKS (the bound the sender already asserts), and the\npayload is large enough to hold the claimed locks. Conforming recovery\nand migration messages are unaffected." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - DLM_MIG_LOCKRES is received and dispatched by the ocfs2 o2net TCP cluster transport, so dlm_mig_lockres_handler() is reached through network protocol messages from a peer node.\nAC:L - A cluster peer can send a crafted DLM_MIG_LOCKRES with attacker-chosen lockname_len and num_locks; the heap overflow and BUG_ON are deterministic and require no race or other condition outside the attacker's control.\nPR:N - o2net gates peers by configured node IP, heartbeat, and the DLM domain key, with no user authentication or target-local privilege check before the handler runs, so exploitation needs no account on the victim.\nUI:N - Once the OCFS2/DLM domain is joined, exploitation is driven entirely by attacker-sent o2net messages and requires no victim user action such as mounting or opening a file.\nS:U - The heap corruption and resulting kernel impact remain within the same kernel and OCFS2 cluster-node security authority and do not cross a guest-to-host or IOMMU boundary.\nC:H - Unchecked lockname_len and num_locks produce a heap out-of-bounds write of attacker-controlled bytes and an out-of-bounds read past the kmalloc message copy, which can disclose adjacent kernel memory.\nI:H - dlm_init_lockres() memcpy()s up to 255 attacker-controlled bytes into a 32-byte o2dlm_lockname slab object, a heap out-of-bounds write that can overwrite adjacent objects and hijack kernel control flow.\nA:H - dlm_process_recovery_data() walks mres->ml[] past the allocated message and hits BUG_ON, and the heap overflow can oops or panic the receiving node." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ocfs2/dlm/dlmrecovery.c" ], "versions": [ { "version": "6714d8e86bf443f6f7af50f9d432025649f091f5", "lessThan": "4a5798253212093b9ff7d90c6cfbe348bcda1594", "status": "affected", "versionType": "git" }, { "version": "6714d8e86bf443f6f7af50f9d432025649f091f5", "lessThan": "dce05b17db862f47ff60614017abe639b2e71cad", "status": "affected", "versionType": "git" }, { "version": "6714d8e86bf443f6f7af50f9d432025649f091f5", "lessThan": "0e999d56917f861f97adb961617b1828c9eb4733", "status": "affected", "versionType": "git" }, { "version": "6714d8e86bf443f6f7af50f9d432025649f091f5", "lessThan": "77686fa5bba135252d348e2dacf481fc19f60c41", "status": "affected", "versionType": "git" }, { "version": "6714d8e86bf443f6f7af50f9d432025649f091f5", "lessThan": "f33041906885f96e190cde54e61ddc69de39e3ee", "status": "affected", "versionType": "git" }, { "version": "6714d8e86bf443f6f7af50f9d432025649f091f5", "lessThan": "50c4cc9183e11f83427efbf770f54851f4471c02", "status": "affected", "versionType": "git" }, { "version": "6714d8e86bf443f6f7af50f9d432025649f091f5", "lessThan": "a8facb1670b4a0612183198e758d9539ef628ed9", "status": "affected", "versionType": "git" }, { "version": "6714d8e86bf443f6f7af50f9d432025649f091f5", "lessThan": "b54e03d9b3697d25f4a0063cf717d459c5e3ad94", "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/dlmrecovery.c" ], "versions": [ { "version": "2.6.16", "status": "affected" }, { "version": "0", "lessThan": "2.6.16", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.270", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "2.6.16", "versionEndExcluding": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.16", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.16", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.16", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.16", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.16", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.16", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.16", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4a5798253212093b9ff7d90c6cfbe348bcda1594" }, { "url": "https://git.kernel.org/stable/c/dce05b17db862f47ff60614017abe639b2e71cad" }, { "url": "https://git.kernel.org/stable/c/0e999d56917f861f97adb961617b1828c9eb4733" }, { "url": "https://git.kernel.org/stable/c/77686fa5bba135252d348e2dacf481fc19f60c41" }, { "url": "https://git.kernel.org/stable/c/f33041906885f96e190cde54e61ddc69de39e3ee" }, { "url": "https://git.kernel.org/stable/c/50c4cc9183e11f83427efbf770f54851f4471c02" }, { "url": "https://git.kernel.org/stable/c/a8facb1670b4a0612183198e758d9539ef628ed9" }, { "url": "https://git.kernel.org/stable/c/b54e03d9b3697d25f4a0063cf717d459c5e3ad94" } ], "title": "ocfs2: validate lengths in dlm_mig_lockres_handler", "x_generator": { "engine": "bippy-1.2.0" } } } }