4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oliver Neukum <oneukum@xxxxxxxx> commit 8835ba4a39cf53f705417b3b3a94eb067673f2c9 upstream. An attack has become available which pretends to be a quirky device circumventing normal sanity checks and crashes the kernel by an insufficient number of interfaces. This patch adds a check to the code path for quirky devices. Signed-off-by: Oliver Neukum <ONeukum@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/class/cdc-acm.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -1114,6 +1114,9 @@ static int acm_probe(struct usb_interfac if (quirks == NO_UNION_NORMAL) { data_interface = usb_ifnum_to_if(usb_dev, 1); control_interface = usb_ifnum_to_if(usb_dev, 0); + /* we would crash */ + if (!data_interface || !control_interface) + return -ENODEV; goto skip_normal_probe; } -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html