r0 = syz_open_dev$tty20(0xc, 0x4, 0x0) ioctl$TIOCVHANGUP(r0, 0x5437, 0x0) writev(r0, &(0x7f00000000c0)=[{&(0x7f0000000000)="f4", 0x1}], 0x1)