Kernel crash via unchecked dangling DLM pointer
Published Oct 7, 2025 · Updated Oct 7, 2025
Improper pointer handling in the Linux kernel DLM allows local users to crash affected systems through an invalid pointer dereference. The send path in fs/dlm/lock.c copies lock-value-block data from sb_lvbptr when that pointer is non-null without first requiring DLM_LKF_VALBLK, so a dangling value reaches memcpy. Reachability requires local low-privileged access and a DLM caller that leaves sb_lvbptr dangling while omitting the flag; the demonstrated consequence is a kernel oops and service interruption.
Summary
What happened
Improper pointer handling in the Linux kernel DLM allows local users to crash affected systems through an invalid pointer dereference. The send path in fs/dlm/lock.c copies lock-value-block data from sb_lvbptr when that pointer is non-null without first requiring DLM_LKF_VALBLK, so a dangling value reaches memcpy. Reachability requires local low-privileged access and a DLM caller that leaves sb_lvbptr dangling while omitting the flag; the demonstrated consequence is a kernel oops and service interruption.
The record
- CVE
- CVE-2022-50516
- Published
- Oct 7, 2025
- Updated
- Oct 7, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 7, 2025CVE publishedPublication date reported by the CVE source.
- Oct 7, 2025Record updatedLatest update available in the CVE record.
Exploitability
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Is a vulnerable build present?
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- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1ab6d3030652b5de0015176a5b0ad9df9b847514
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <57c1cfb5781068e5d3632bc6e5f74a8fcc4f1a30
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7175e131ebba47afef47e6ac4d5bab474d1e6e49
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ea7be82fd7e1f5de72208bce93fbbe6de6c13dec
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What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
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Your stack
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