[PATCH 3/7] Input: ims-pcu - fix NULL-deref at probe

From: Johan Hovold
Date: Mon Mar 13 2017 - 08:37:06 EST


Make sure to check the number of endpoints to avoid dereferencing a
NULL-pointer should a malicious device lack control-interface endpoints.

Fixes: 628329d52474 ("Input: add IMS Passenger Control Unit driver")
Cc: stable <stable@xxxxxxxxxxxxxxx> # 3.10
Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
drivers/input/misc/ims-pcu.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/input/misc/ims-pcu.c b/drivers/input/misc/ims-pcu.c
index 9c0ea36913b4..f4e8fbec6a94 100644
--- a/drivers/input/misc/ims-pcu.c
+++ b/drivers/input/misc/ims-pcu.c
@@ -1667,6 +1667,10 @@ static int ims_pcu_parse_cdc_data(struct usb_interface *intf, struct ims_pcu *pc
return -EINVAL;

alt = pcu->ctrl_intf->cur_altsetting;
+
+ if (alt->desc.bNumEndpoints < 1)
+ return -ENODEV;
+
pcu->ep_ctrl = &alt->endpoint[0].desc;
pcu->max_ctrl_size = usb_endpoint_maxp(pcu->ep_ctrl);

--
2.12.0