4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oliver Neukum <oneukum@xxxxxxxx> commit 9397940ed812b942c520e0c25ed4b2c64d57e8b9 upstream. If a device splits up a control message and a reset() happens between the parts, the message is lost and already recieved parts must be dropped. Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx> Fixes: 1aba579f3cf51 ("cdc-acm: handle read pipe errors") Cc: stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/class/cdc-acm.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -1641,6 +1641,7 @@ static int acm_pre_reset(struct usb_inte struct acm *acm = usb_get_intfdata(intf); clear_bit(EVENT_RX_STALL, &acm->flags); + acm->nb_index = 0; /* pending control transfers are lost */ return 0; }