Input: ims-pcu - sanity check against missing interfaces

A malicious device missing interface can make the driver oops.
Add sanity checking.

Signed-off-by: Oliver Neukum <ONeukum@suse.com>
CC: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/misc/ims-pcu.c b/drivers/input/misc/ims-pcu.c
index ac1fa5f4458052a97d5e8793123ce6b54623a9fa..9c0ea36913b4a98293911f62a2d649dc08a855cd 100644 (file)
--- a/drivers/input/misc/ims-pcu.c
+++ b/drivers/input/misc/ims-pcu.c
@@ -1663,6 +1663,8 @@ static int ims_pcu_parse_cdc_data(struct usb_interface *intf, struct ims_pcu *pc
 
        pcu->ctrl_intf = usb_ifnum_to_if(pcu->udev,
                                         union_desc->bMasterInterface0);
+       if (!pcu->ctrl_intf)
+               return -EINVAL;
 
        alt = pcu->ctrl_intf->cur_altsetting;
        pcu->ep_ctrl = &alt->endpoint[0].desc;
@@ -1670,6 +1672,8 @@ static int ims_pcu_parse_cdc_data(struct usb_interface *intf, struct ims_pcu *pc
 
        pcu->data_intf = usb_ifnum_to_if(pcu->udev,
                                         union_desc->bSlaveInterface0);
+       if (!pcu->data_intf)
+               return -EINVAL;
 
        alt = pcu->data_intf->cur_altsetting;
        if (alt->desc.bNumEndpoints != 2) {