staging: rtl8712: fix interface sanity check

BugLink: https://bugs.launchpad.net/bugs/1857158
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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/staging/rtl8712/usb_intf.c b/drivers/staging/rtl8712/usb_intf.c
index 85eadddfaf06092e1525c762c9c0334418844d01..5e2cdc25401bad4a76333fa969d73a2ac7d5fed6 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) {