{"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":"2026-09-14T12:00:28.925Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-14T12:00:28.925Z"},"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-rc1","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-rc1"}]}]}],"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"}}}}