[PATCH 06/11] Input: ims-pcu - validate control endpoint type

[Dmitry Torokhov]

The driver currently assumes that the first endpoint of the control
interface is an interrupt IN endpoint without verifying it. A malicious
device could provide a different endpoint type, which would then be
passed to usb_fill_int_urb(), potentially leading to kernel warnings
or undefined behavior.

Verify that the control endpoint is an interrupt IN endpoint.

Fixes: 628329d52474 ("Input: add IMS Passenger Control Unit driver")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Sashiko bot <sashiko-bot@xxxxxxxxxx>
Assisted-by: Gemini:gemini-3.1-pro
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
 drivers/input/misc/ims-pcu.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/input/misc/ims-pcu.c b/drivers/input/misc/ims-pcu.c
index 7fdff9dd1b5f..0e7a783526e6 100644
--- a/drivers/input/misc/ims-pcu.c
+++ b/drivers/input/misc/ims-pcu.c
@@ -1703,6 +1703,12 @@ static int ims_pcu_parse_cdc_data(struct usb_interface *intf, struct ims_pcu *pc
 		return -ENODEV;
 
 	pcu->ep_ctrl = &alt->endpoint[0].desc;
+	if (!usb_endpoint_is_int_in(pcu->ep_ctrl)) {
+		dev_err(pcu->dev,
+			"Control endpoint is not INTERRUPT IN\n");
+		return -EINVAL;
+	}
+
 	pcu->max_ctrl_size = usb_endpoint_maxp(pcu->ep_ctrl);
 
 	pcu->data_intf = usb_ifnum_to_if(pcu->udev,
-- 
2.54.0.746.g67dd491aae-goog