Kernel panic via misclassified user-access fixups
Published Apr 2, 2024 · Updated May 11, 2026
Improper exception handling in Linux kernel 6.4 allows local users to panic the kernel during an in-kernel machine check. The x86 get_user() and put_user() exception tables classify user-memory fixups as EX_TYPE_DEFAULT, so machine-check handling panics instead of invoking the recoverable EX_TYPE_UACCESS path. Reachability requires a machine check during a kernel access to user memory; the demonstrated consequence is a host-wide crash.
Summary
What happened
Improper exception handling in Linux kernel 6.4 allows local users to panic the kernel during an in-kernel machine check. The x86 get_user() and put_user() exception tables classify user-memory fixups as EX_TYPE_DEFAULT, so machine-check handling panics instead of invoking the recoverable EX_TYPE_UACCESS path. Reachability requires a machine check during a kernel access to user memory; the demonstrated consequence is a host-wide crash.
The record
- CVE
- CVE-2024-26674
- Published
- Apr 2, 2024
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-787, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 2, 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?
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- Affected versionversion=6.4
- Affected versionversion=b19b74bc99b1501a550f4448d04d59b946dc617a <2aed1b6c33afd8599d01c6532bbecb829480a674
- Affected versionversion=b19b74bc99b1501a550f4448d04d59b946dc617a <2da241c5ed78d0978228a1150735539fe1a60eca
- Affected versionversion=b19b74bc99b1501a550f4448d04d59b946dc617a <8eed4e00a370b37b4e5985ed983dccedd555ea9d
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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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