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Vulnerability DatabaseCVE-2025-39836
CVE-2025-39836:
Linux Kernel vulnerability analysis and mitigation
Overview
CVE-2025-39836 affects the Linux kernel, specifically related to an incorrect buffer allocation method in the EFI STMM component. The vulnerability was discovered and disclosed in September 2025, impacting various Linux distributions including Debian Trixie (Debian Security).
Technical details
The vulnerability stems from a communication buffer allocation issue where setupmmhdr() uses kmalloc() instead of the required contiguous pages expected by teeshmregisterkernelbuf(). This mismatch can lead to various corruptions or BUGs, particularly after the implementation of commit 9aec2fb0fd5e ("slab: allocate frozen pages"). The issue has been assigned a CVSS v3 Base Score of 5.5 (MEDIUM) (Red Hat Portal).
Impact
The vulnerability can potentially cause system corruptions and BUGs in the Linux kernel's EFI STMM component, affecting the stability and security of the system (Debian Security).
Mitigation and workarounds
The vulnerability has been fixed in Linux kernel version 6.12.48-1 for Debian Trixie. The fix involves changing the buffer allocation method from kmalloc() to allocpagesexact(). Users are recommended to upgrade their Linux packages to the patched versions (Debian Security Announce).
Additional resources
Source: This report was generated using AI
Related Linux Kernel vulnerabilities:
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