brcmfmac: fix interface sanity check

commit 3428fbcd6e6c0850b1a8b2a12082b7b2aabb3da3 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: 71bb244ba2fd ("brcm80211: fmac: add USB support for bcm43235/6/8 chipsets")
Cc: stable <stable@vger.kernel.org>     # 3.4
Cc: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
index acf513fd9e6d5aeef3170aa68f1497f228198477..05df9d8f76e9cc4921a8175bd90987e96b8f9ac4 100644 (file)
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
@@ -1330,7 +1330,7 @@ brcmf_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
                goto fail;
        }
 
-       desc = &intf->altsetting[0].desc;
+       desc = &intf->cur_altsetting->desc;
        if ((desc->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
            (desc->bInterfaceSubClass != 2) ||
            (desc->bInterfaceProtocol != 0xff)) {
@@ -1343,7 +1343,7 @@ brcmf_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 
        num_of_eps = desc->bNumEndpoints;
        for (ep = 0; ep < num_of_eps; ep++) {
-               endpoint = &intf->altsetting[0].endpoint[ep].desc;
+               endpoint = &intf->cur_altsetting->endpoint[ep].desc;
                endpoint_num = usb_endpoint_num(endpoint);
                if (!usb_endpoint_xfer_bulk(endpoint))
                        continue;