USB: cdc-acm: more sanity checking

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@suse.com>
CC: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Oliver Neukum 2016-03-15 10:14:04 +01:00 committed by Greg Kroah-Hartman
parent 0b818e3956
commit 8835ba4a39

View File

@ -1179,6 +1179,9 @@ static int acm_probe(struct usb_interface *intf,
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;
}