Exploit for CVE-2026-31431

## https://sploitus.com/exploit?id=B9D274A2-4F9D-5E56-BAC0-6E32FE00CC48
copy.fail — AF_ALG AEAD splice primitive - CVE-2026-31431

C port of the Python prototype by offsecguy. Uses kernel crypto API
(AF_ALG) with authencesn(hmac(sha256),cbc(aes)) AEAD, MSG_MORE + 
splice to feed data from a read-only fd through the crypto socket, 
chunk by chunk

compile via: musl-gcc -static -Os -s -o exp exp.c -I./zlib-1.3.2 -L./zlib-1.3.2 -lz

or

statically linked	: gcc exp.c -o exp -lz -s -static
dynamically linked	: gcc exp.c -o exp -lz -s