CVE-2026-89494ocfs2: validate lengths in dlm_mig_lockres_handler
- 9.8CriticalCVSS base score
- 0.71%Exploitation in 30 daysEPSS · top 46% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: ocfs2: validate lengths in dlm_mig_lockres_handler A node receiving a DLM_MIG_LOCKRES message trusts several fields of the peer-supplied dlm_migratable_lockres without validation. num_locks and lockname_len are bounded only on the sending side, and the message is never checked to actually carry num_locks migratable_lock entries. As a result dlm_process_recovery_data() walks mres->ml[0..num_locks) past the kmalloc(data_len) copy of the message (an out-of-bounds read that ends in a BUG_ON panic), and dlm_init_lockres() copies lockname_len bytes into the fixed 32-byte o2dlm_lockname slab object (a heap out-of-bounds write). Both are reachable by any node in the domain. Validate these fields right after dlm_grab(), before anything uses them -- including the not-joined error path, which already prints mres->lockname with the unbounded lockname_len as a %.*s precision. Reject the message unless lockname_len <= DLM_LOCKID_NAME_MAX, num_locks <= DLM_MAX_MIGRATABLE_LOCKS (the bound the sender already asserts), and the payload is large enough to hold the claimed locks. Conforming recovery and migration messages are unaffected.
Timeline
ID reserved
By Linux
Published
- 38 days later
· 38 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Received | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.71% · top 46% of all CVEs (14 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
- affected 6714d8e86bf443f6f7af50f9d432025649f091f5 – < 4a5798253212093b9ff7d90c6cfbe348bcda1594
- affected 6714d8e86bf443f6f7af50f9d432025649f091f5 – < dce05b17db862f47ff60614017abe639b2e71cad
- affected 6714d8e86bf443f6f7af50f9d432025649f091f5 – < 0e999d56917f861f97adb961617b1828c9eb4733
- affected 6714d8e86bf443f6f7af50f9d432025649f091f5 – < 77686fa5bba135252d348e2dacf481fc19f60c41
- affected 6714d8e86bf443f6f7af50f9d432025649f091f5 – < f33041906885f96e190cde54e61ddc69de39e3ee
- affected 6714d8e86bf443f6f7af50f9d432025649f091f5 – < 50c4cc9183e11f83427efbf770f54851f4471c02
- affected 6714d8e86bf443f6f7af50f9d432025649f091f5 – < a8facb1670b4a0612183198e758d9539ef628ed9
- affected 6714d8e86bf443f6f7af50f9d432025649f091f5 – < b54e03d9b3697d25f4a0063cf717d459c5e3ad94
- affected 2.6.16
- unaffected < 2.6.16
- unaffected 5.10.270 – ≤ 5.10.*
- unaffected 5.15.221 – ≤ 5.15.*
- unaffected 6.1.188 – ≤ 6.1.*
- unaffected 6.6.157 – ≤ 6.6.*
- unaffected 6.12.109 – ≤ 6.12.*
- unaffected 6.18.50 – ≤ 6.18.*
- unaffected 7.2.4 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References8
- https://git.kernel.org/stable/c/4a5798253212093b9ff7d90c6cfbe348bcda1594 (opens in a new tab)
- https://git.kernel.org/stable/c/dce05b17db862f47ff60614017abe639b2e71cad (opens in a new tab)
- https://git.kernel.org/stable/c/0e999d56917f861f97adb961617b1828c9eb4733 (opens in a new tab)
- https://git.kernel.org/stable/c/77686fa5bba135252d348e2dacf481fc19f60c41 (opens in a new tab)
- https://git.kernel.org/stable/c/f33041906885f96e190cde54e61ddc69de39e3ee (opens in a new tab)
- https://git.kernel.org/stable/c/50c4cc9183e11f83427efbf770f54851f4471c02 (opens in a new tab)
- https://git.kernel.org/stable/c/a8facb1670b4a0612183198e758d9539ef628ed9 (opens in a new tab)
- https://git.kernel.org/stable/c/b54e03d9b3697d25f4a0063cf717d459c5e3ad94 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-76400 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://cveledger.app/cve/CVE-2026-89494)Record last updated .