Local privilege escalation via dlmfs use-after-free
Published Feb 26, 2025 · Updated Aug 5, 2026
Use-after-free in Linux kernel OCFS2 dlmfs allows local users to crash the kernel or escalate privileges through lock inode operations. After user_dlm_destroy_lock fails, it leaves USER_LOCK_IN_TEARDOWN or USER_LOCK_BUSY set, so a later unlink frees an inode while its DLM lock remains linked. Exploitation requires local write access to a mounted dlmfs domain; a subsequent blocking AST reaches the freed lock object and can panic the kernel or enable kernel-level code execution.
Summary
What happened
Use-after-free in Linux kernel OCFS2 dlmfs allows local users to crash the kernel or escalate privileges through lock inode operations. After user_dlm_destroy_lock fails, it leaves USER_LOCK_IN_TEARDOWN or USER_LOCK_BUSY set, so a later unlink frees an inode while its DLM lock remains linked. Exploitation requires local write access to a mounted dlmfs domain; a subsequent blocking AST reaches the freed lock object and can panic the kernel or enable kernel-level code execution.
The record
- CVE
- CVE-2022-49337
- Published
- Feb 26, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-416, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 26, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 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?
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- Affected versionversion=2.6.17
- Affected versionversion=2cd9888590c52ac7592e3607d0a3174ccd57ef86 <02480e2e82ae0e5588374bbbcf4fa6e4959fa174
- Affected versionversion=2cd9888590c52ac7592e3607d0a3174ccd57ef86 <1434cd71ad9f3a6beda3036972983b6c4869207c
- Affected versionversion=2cd9888590c52ac7592e3607d0a3174ccd57ef86 <2c5e26a626fe46675bceba853e12aaf13c712e10
- Affected versionversion=2cd9888590c52ac7592e3607d0a3174ccd57ef86 <337e36550788dbe03254f0593a231c1c4873b20d
- Affected versionversion=2cd9888590c52ac7592e3607d0a3174ccd57ef86 <733a35c00ef363a1c774d7ea486e0735b7c13a15
- Affected versionversion=2cd9888590c52ac7592e3607d0a3174ccd57ef86 <82bf8e7271fade40184177cb406203addc34c4a0
- Affected versionversion=2cd9888590c52ac7592e3607d0a3174ccd57ef86 <863e0d81b6683c4cbc588ad831f560c90e494bef
- Affected versionversion=2cd9888590c52ac7592e3607d0a3174ccd57ef86 <9c96238fac045b289993d7bc5aae7b2d72b25c76
- Affected versionversion=2cd9888590c52ac7592e3607d0a3174ccd57ef86 <efb54ec548829e1d3605f0434526f86e345b1b28
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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