ucom: device still open, forcing close   <- usb_serial.c:570 during detach with open fd
uftdi0: at uhub0, port 2, addr 2 (disconnected)
uftdi0: detached

--- PoC gauntlet (ucom_uaf /dev/cuaU0), fd still open across the unplug ---
[*] opened /dev/cuaU0 fd=3 uid=1001
[*] pre-detach tcgetattr OK: ispeed=0 ospeed=0 cflag=0x0
[*] detach confirmed (go file present); now poking freed softc
[1] TIOCMGET rc=-1 errno=9 val=0x0      (EBADF: devfs revoked the vnode)
[2] tcgetattr rc=-1 errno=9
[3] TIOCFLUSH rc=-1 errno=9
[4] TIOCCBRK rc=-1 errno=9
[5] write rc=-1 errno=9
[6] close rc=0 errno=9
[*] survived; if the kernel is still alive the UAF was silent

--- race storm (ucom_race /dev/cuaU0, 8 threads), 21 attach/detach cycles ---
[*] storm finished                       (guest alive, no panic, no corruption)