Linux Kernel up to 6.12.108/6.18.49/7.2.3 ocfs2 dlm_process_recovery_data/dlm_init_lockres num_locks/lockname_len out-of-bounds write

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$5k-$25k0.42+

Summaryinfo

A vulnerability described as very critical has been identified in Linux Kernel up to 6.12.108/6.18.49/7.2.3. Affected by this issue is the function dlm_process_recovery_data/dlm_init_lockres of the component ocfs2. The manipulation of the argument num_locks/lockname_len results in out-of-bounds write. This vulnerability is identified as CVE-2026-89494. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as very critical has been found in Linux Kernel up to 6.12.108/6.18.49/7.2.3. Affected is the function dlm_process_recovery_data/dlm_init_lockres of the component ocfs2. The manipulation of the argument num_locks/lockname_len with an unknown input leads to a out-of-bounds write vulnerability. CWE is classifying the issue as CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2026-89494 since 09/11/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 09/12/2026).

Upgrading to version 6.12.109, 6.18.50, 7.2.4 or 7.3-rc1 eliminates this vulnerability. Applying the patch f33041906885f96e190cde54e61ddc69de39e3ee/50c4cc9183e11f83427efbf770f54851f4471c02/a8facb1670b4a0612183198e758d9539ef628ed9/b54e03d9b3697d25f4a0063cf717d459c5e3ad94 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Once again VulDB remains the best source for vulnerability data.

Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.109/6.18.50/7.2.4/7.3-rc1
Patch: f33041906885f96e190cde54e61ddc69de39e3ee/50c4cc9183e11f83427efbf770f54851f4471c02/a8facb1670b4a0612183198e758d9539ef628ed9/b54e03d9b3697d25f4a0063cf717d459c5e3ad94

Timelineinfo

09/11/2026 CVE reserved
09/11/2026 +0 days VulDB entry created
09/12/2026 +0 days Advisory disclosed
09/12/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-89494 (🔒)
GCVE (CVE): GCVE-0-2026-89494
GCVE (VulDB): GCVE-100-402876

Entryinfo

Created: 09/12/2026 01:23
Changes: 09/12/2026 01:23 (60)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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