From: Joakim Tjernlund <joakim.tjernlund@xxxxxxxxxxxx> commit 03894573f2913181ee5aae0089f333b2131f2d4b upstream. USB_DEVICE(0x0424, 0x274e) can send data before cdc_acm is ready, causing garbage chars on the TTY causing stray input to the shell and/or login prompt. Signed-off-by: Joakim Tjernlund <joakim.tjernlund@xxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Acked-by: Oliver Neukum <oneukum@xxxxxxxx> Link: https://lore.kernel.org/r/20200605105418.22263-1-joakim.tjernlund@xxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/class/cdc-acm.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index f67088bb8218b..d5187b50fc828 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -1689,6 +1689,8 @@ static int acm_pre_reset(struct usb_interface *intf) static const struct usb_device_id acm_ids[] = { /* quirky and broken devices */ + { USB_DEVICE(0x0424, 0x274e), /* Microchip Technology, Inc. (formerly SMSC) */ + .driver_info = DISABLE_ECHO, }, /* DISABLE ECHO in termios flag */ { USB_DEVICE(0x076d, 0x0006), /* Denso Cradle CU-321 */ .driver_info = NO_UNION_NORMAL, },/* has no union descriptor */ { USB_DEVICE(0x17ef, 0x7000), /* Lenovo USB modem */ -- 2.25.1
