Kernel panic via premature Hyper-V channel callback
Published Jan 11, 2025 · Updated May 11, 2026
NULL pointer dereference in Linux Hyper-V utilities allows local users to crash affected kernels by racing KVP or VSS startup. A daemon can register through its character device before util_probe() finishes vmbus_open(), causing kvp_register_done() to invoke a callback that dereferences an uninitialized ring buffer. Triggering the race requires local low-privilege access to a Hyper-V guest using KVP or VSS, and the bounded consequence is a kernel panic and service interruption.
Summary
What happened
NULL pointer dereference in Linux Hyper-V utilities allows local users to crash affected kernels by racing KVP or VSS startup. A daemon can register through its character device before util_probe() finishes vmbus_open(), causing kvp_register_done() to invoke a callback that dereferences an uninitialized ring buffer. Triggering the race requires local low-privilege access to a Hyper-V guest using KVP or VSS, and the bounded consequence is a kernel panic and service interruption.
The record
- CVE
- CVE-2024-55916
- Published
- Jan 11, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-476, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 11, 2025CVE publishedPublication date reported by the CVE source.
- May 11, 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=4.9
- Affected versionversion=e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c <042253c57be901bfd19f15b68267442b70f510d5
- Affected versionversion=e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c <07a756a49f4b4290b49ea46e089cbe6f79ff8d26
- Affected versionversion=e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c <3dd7a30c6d7f90afcf19e9b072f572ba524d7ec6
- Affected versionversion=e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c <718fe694a334be9d1a89eed22602369ac18d6583
- Affected versionversion=e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c <89fcec5e466b3ac9b376e0d621c71effa1a7983f
- Affected versionversion=e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c <d81f4e73aff9b861671df60e5100ad25cc16fbf8
- Affected versionversion=e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c <f091a224a2c82f1e302b1768d73bb6332f687321
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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