Double Free Vulnerability in Linux Kernel's Page Table Management

CVE-2026-31686

What is CVE-2026-31686?

A vulnerability in the Linux kernel's memory management system, specifically within the KASAN (Kernel Address Sanitizer) mechanism, leads to a double free condition when handling page tables. This issue arises particularly in the powerpc architecture, where it was assumed that the page table structure would always be aligned with the sizes defined in memory management. The flaw causes KASAN to incorrectly free memory associated with the page table, potentially leading to memory corruption and other unforeseen consequences in systems reliant on these operations. This issue has been addressed by modifying how the kernel calculates the address of the page tables, ensuring alignment and preventing further double free occurrences.

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