Kernel panic via unfiltered vsyscall branch address
Published Feb 29, 2024 · Updated May 11, 2026
Denial of service in the Linux kernel allows local users to trigger a kernel panic through an interrupted vsyscall during LBR sampling. The perf x86 LBR filter passes a vsyscall-region branch address to the instruction decoder, whose next_byte dereference faults because that region is not normally mapped. Exploitation requires permitted Last Branch Record sampling and an NMI to interrupt the local user's vsyscall; the resulting unhandled page fault interrupts the host.
Summary
What happened
Denial of service in the Linux kernel allows local users to trigger a kernel panic through an interrupted vsyscall during LBR sampling. The perf x86 LBR filter passes a vsyscall-region branch address to the instruction decoder, whose next_byte dereference faults because that region is not normally mapped. Exploitation requires permitted Last Branch Record sampling and an NMI to interrupt the local user's vsyscall; the resulting unhandled page fault interrupts the host.
The record
- CVE
- CVE-2023-52476
- Published
- Feb 29, 2024
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 29, 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=5.16
- Affected versionversion=808b64565b028bd072c985624d5cbe4b6f5a5a35 <3863989497652488a50f00e96de4331e5efabc6c
- Affected versionversion=808b64565b028bd072c985624d5cbe4b6f5a5a35 <e53899771a02f798d436655efbd9d4b46c0f9265
- Affected versionversion=808b64565b028bd072c985624d5cbe4b6f5a5a35 <f71edacbd4f99c0e12fe4a4007ab4d687d0688db
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
Public exploit references
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Technologies
Your stack
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Your stack
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