brcmfmac: fix interface sanity check

BugLink: https://bugs.launchpad.net/bugs/1864904
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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
index 090b815f8c0f6f42ff4aabdde9920d67c83d3fc8..bd835231ac1fcc7004563e41c8fb2833cd081bf5 100644 (file)
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
@@ -1351,7 +1351,7 @@ 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)) {
@@ -1364,7 +1364,7 @@ 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;