[PATCH 4.4 41/78] Input: kbtab - sanity check for endpoint type

Greg Kroah-Hartman
2019-08-22T17:47:30Z

From: Oliver Neukum <oneukum@suse.com>

commit c88090dfc84254fa149174eb3e6a8458de1912c4 upstream.

The driver should check whether the endpoint it uses has the correct
type.

Reported-by: syzbot+c7df50363aaff50aa363@syzkaller.appspotmail.com
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/input/tablet/kbtab.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/input/tablet/kbtab.c
+++ b/drivers/input/tablet/kbtab.c
@@ -125,6 +125,10 @@ static int kbtab_probe(struct usb_interf
if (intf->cur_altsetting->desc.bNumEndpoints < 1)
return -ENODEV;

+ endpoint = &intf->cur_altsetting->endpoint[0].desc;
+ if (!usb_endpoint_is_int_in(endpoint))
+ return -ENODEV;
+
kbtab = kzalloc(sizeof(struct kbtab), GFP_KERNEL);
input_dev = input_allocate_device();
if (!kbtab || !input_dev)
@@ -164,8 +168,6 @@ static int kbtab_probe(struct usb_interf
input_set_abs_params(input_dev, ABS_Y, 0, 0x1750, 4, 0);
input_set_abs_params(input_dev, ABS_PRESSURE, 0, 0xff, 0, 0);

- endpoint = &intf->cur_altsetting->endpoint[0].desc;
-
usb_fill_int_urb(kbtab->irq, dev,
usb_rcvintpipe(dev, endpoint->bEndpointAddress),
kbtab->data, 8,