Incorrect EFI region sizing via integer truncation
Published Apr 17, 2024 · Updated May 11, 2026
Integer overflow in Linux kernel 5.5 through 6.8-rc3 allows attackers to truncate an EFI soft-reserved region's recorded size. In arm_enable_runtime_services() and riscv_enable_runtime_services(), md_size was an int, so converting the 64-bit page count to bytes narrowed the value before res->end was calculated. The condition requires ARM64 or RISC-V EFI startup with soft reservation enabled and a descriptor containing at least 4GB worth of pages; public sources identify no practical attacker-controlled input path.
Summary
What happened
Integer overflow in Linux kernel 5.5 through 6.8-rc3 allows attackers to truncate an EFI soft-reserved region's recorded size. In arm_enable_runtime_services() and riscv_enable_runtime_services(), md_size was an int, so converting the 64-bit page count to bytes narrowed the value before res->end was calculated. The condition requires ARM64 or RISC-V EFI startup with soft reservation enabled and a descriptor containing at least 4GB worth of pages; public sources identify no practical attacker-controlled input path.
The record
- CVE
- CVE-2024-26843
- Published
- Apr 17, 2024
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-787
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Apr 17, 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=16993c0f0a43213e23666ea40e9163887f593ac7 <156cb12ffdcf33883304f0db645e1eadae712fe0
- Affected versionversion=16993c0f0a43213e23666ea40e9163887f593ac7 <4aa36b62c3eaa869860bf78b1146e9f2b5f782a9
- Affected versionversion=16993c0f0a43213e23666ea40e9163887f593ac7 <4fff3d735baea104017f2e3c245e27cdc79f2426
- Affected versionversion=16993c0f0a43213e23666ea40e9163887f593ac7 <700c3f642c32721f246e09d3a9511acf40ae42be
- Affected versionversion=16993c0f0a43213e23666ea40e9163887f593ac7 <cf3d6813601fe496de7f023435e31bfffa74ae70
- Affected versionversion=16993c0f0a43213e23666ea40e9163887f593ac7 <de1034b38a346ef6be25fe8792f5d1e0684d5ff4
- Affected versionversion=5.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
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