Kernel memory disclosure via stale LVB pointer
Published Aug 15, 2026 · Updated Aug 15, 2026
Use-after-free in Linux kernel OCFS2 allows local privileged users to disclose memory or crash the kernel by racing a debugfs read. The locking_state iterator copies an ocfs2_lock_res but leaves sb_lvbptr referencing the original owner, which teardown can free before ocfs2_dlm_seq_show reads the LVB. Exploitation requires privileged debugfs access, an OCFS2 userspace fsdlm lock, and a concurrent lock-resource teardown.
Summary
What happened
Use-after-free in Linux kernel OCFS2 allows local privileged users to disclose memory or crash the kernel by racing a debugfs read. The locking_state iterator copies an ocfs2_lock_res but leaves sb_lvbptr referencing the original owner, which teardown can free before ocfs2_dlm_seq_show reads the LVB. Exploitation requires privileged debugfs access, an OCFS2 userspace fsdlm lock, and a concurrent lock-resource teardown.
The record
- CVE
- CVE-2026-74351
- Published
- Aug 15, 2026
- Updated
- Aug 15, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Aug 15, 2026CVE publishedPublication date reported by the CVE source.
- Aug 15, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2.6.26
- Affected versionversion=cf4d8d75d8aba537a19b313a9364fd08ddbd5622 <07aa4a8ebacde3d0ba50f60d2964f274ee7629bc
- Affected versionversion=cf4d8d75d8aba537a19b313a9364fd08ddbd5622 <185427b5f7a209254c85c18aad5a4a8e009b2f30
- Affected versionversion=cf4d8d75d8aba537a19b313a9364fd08ddbd5622 <610a0d2a35496738e1472fb0f318d5008a1c634f
- Affected versionversion=cf4d8d75d8aba537a19b313a9364fd08ddbd5622 <6b38a5b8ee951e5b244e9a3c3d28d0f5e7c51411
- Affected versionversion=cf4d8d75d8aba537a19b313a9364fd08ddbd5622 <8614a8f7e81edd34c9f67e454e7024fd12a2a341
- Affected versionversion=cf4d8d75d8aba537a19b313a9364fd08ddbd5622 <93612d48fa42b3d1a637eb9279e15281c611c000
- Affected versionversion=cf4d8d75d8aba537a19b313a9364fd08ddbd5622 <bb44a7690a4d553da705919cf666a80f5ca9011c
- Affected versionversion=cf4d8d75d8aba537a19b313a9364fd08ddbd5622 <e037c1250cc90e7aacb002357d1b0399fc65ecfc
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
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Public exploit references
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Technologies
Your stack
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Your stack
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