[PATCH AUTOSEL 4.19 35/68] Input: kbtab - sanity check for endpoint type

Sasha Levin
2019-08-14T02:31:00Z

From: Oliver Neukum <oneukum@suse.com>

[ Upstream commit c88090dfc84254fa149174eb3e6a8458de1912c4 ]

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: Sasha Levin <sashal@kernel.org>
---
drivers/input/tablet/kbtab.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/input/tablet/kbtab.c b/drivers/input/tablet/kbtab.c
index 75b500651e4e4..b1cf0c9712740 100644
--- a/drivers/input/tablet/kbtab.c
+++ b/drivers/input/tablet/kbtab.c
@@ -116,6 +116,10 @@ static int kbtab_probe(struct usb_interface *intf, const struct usb_device_id *i
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)
@@ -154,8 +158,6 @@ static int kbtab_probe(struct usb_interface *intf, const struct usb_device_id *i
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,
--
2.20.1