Boot-time kernel corruption via stale memblock free
Published May 1, 2024 · Updated Aug 5, 2026
Use-after-free in Linux kernel bootconfig allows local users to corrupt kernel memory during boot through a supplied bootconfig. The xbc_exit function calls memblock_free after xbc metadata has passed to the buddy allocator, causing memblock_isolate_range to read and rewrite freed pages. Reachability requires control of boot configuration on a build with CONFIG_BOOT_CONFIG and without CONFIG_ARCH_KEEP_MEMBLOCK; corruption can panic the kernel or prevent startup.
Summary
What happened
Use-after-free in Linux kernel bootconfig allows local users to corrupt kernel memory during boot through a supplied bootconfig. The xbc_exit function calls memblock_free after xbc metadata has passed to the buddy allocator, causing memblock_isolate_range to read and rewrite freed pages. Reachability requires control of boot configuration on a build with CONFIG_BOOT_CONFIG and without CONFIG_ARCH_KEEP_MEMBLOCK; corruption can panic the kernel or prevent startup.
The record
- CVE
- CVE-2024-26983
- Published
- May 1, 2024
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-416, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 1, 2024CVE publishedPublication date reported by the CVE source.
- Aug 5, 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=40caa127f3c7279c75cb0c9684559fa314ee3a66 <1e7feb31a18c197d63a5e606025ed63c762f8918
- Affected versionversion=40caa127f3c7279c75cb0c9684559fa314ee3a66 <5a7dfb8fcd3f29fc93161100179b27f24f3d5f35
- Affected versionversion=40caa127f3c7279c75cb0c9684559fa314ee3a66 <89f9a1e876b5a7ad884918c03a46831af202c8a0
- Affected versionversion=40caa127f3c7279c75cb0c9684559fa314ee3a66 <e46d3be714ad9652480c6db129ab8125e2d20ab7
- Affected versionversion=5.15
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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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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