Local host crash via unallocated cacheinfo dereference
Published Dec 27, 2024 · Updated May 11, 2026
NULL pointer dereference in Linux kernel 6.4 allows local users to crash the kernel during cacheinfo CPU hotplug processing. On x86, the cacheinfo CPU-hotplug callback calls last_level_cache_is_valid() before per-CPU cacheinfo memory exists because no early build occurred. Reachability requires local low-privileged access and a CPU hotplug event; the NULL dereference produces a kernel oops that interrupts host availability.
Summary
What happened
NULL pointer dereference in Linux kernel 6.4 allows local users to crash the kernel during cacheinfo CPU hotplug processing. On x86, the cacheinfo CPU-hotplug callback calls last_level_cache_is_valid() before per-CPU cacheinfo memory exists because no early build occurred. Reachability requires local low-privileged access and a CPU hotplug event; the NULL dereference produces a kernel oops that interrupts host availability.
The record
- CVE
- CVE-2024-56617
- Published
- Dec 27, 2024
- 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
- Dec 27, 2024CVE 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=6.4
- Affected versionversion=6539cffa94957241c096099a57d05fa4d8c7db8a <23b5908b11b77ff8d7b8f7b8f11cbab2e1f4bfc2
- Affected versionversion=6539cffa94957241c096099a57d05fa4d8c7db8a <95e197354e0de07e9a20819bdae6562e4dda0f20
- Affected versionversion=6539cffa94957241c096099a57d05fa4d8c7db8a <b3fce429a1e030b50c1c91351d69b8667eef627b
What conditions does exploitation require?
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
Your stack
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Your stack
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