staging: rtl8712: fix interface sanity check

Make sure to use the current alternate setting when verifying the
interface descriptors to avoid binding to an invalid interface.

Failing to do so could cause the driver to misbehave or trigger a WARN()
in usb_submit_urb() that kernels with panic_on_warn set would choke on.

Fixes: 2865d42c78a9 ("staging: r8712u: Add the new driver to the mainline kernel")
Cc: stable <stable@vger.kernel.org>     # 2.6.37
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191210114751.5119-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/rtl8712/usb_intf.c b/drivers/staging/rtl8712/usb_intf.c
index ba1288297ee4b747b6c741e1faff5a83a08db26a..a87562f632a7ff07a4f7fb405dbb66ad4764f0da 100644 (file)
--- a/drivers/staging/rtl8712/usb_intf.c
+++ b/drivers/staging/rtl8712/usb_intf.c
@@ -247,7 +247,7 @@ static uint r8712_usb_dvobj_init(struct _adapter *padapter)
 
        pdvobjpriv->padapter = padapter;
        padapter->eeprom_address_size = 6;
-       phost_iface = &pintf->altsetting[0];
+       phost_iface = pintf->cur_altsetting;
        piface_desc = &phost_iface->desc;
        pdvobjpriv->nr_endpoint = piface_desc->bNumEndpoints;
        if (pusbd->speed == USB_SPEED_HIGH) {