staging: rtl8712: fix interface sanity check

commit c724f776f048538ecfdf53a52b7a522309f5c504 upstream.

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 897d4621a5ce760a07ca91a24080228a2cb91349..d0ba42dfafebfdedbdb7a55c87063ccd7b1f652b 100644 (file)
--- a/drivers/staging/rtl8712/usb_intf.c
+++ b/drivers/staging/rtl8712/usb_intf.c
@@ -275,7 +275,7 @@ static uint r8712_usb_dvobj_init(struct _adapter *padapter)
 
        pdvobjpriv->padapter = padapter;
        padapter->EepromAddressSize = 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) {