rtl8xxxu: fix interface sanity check

commit 39a4281c312f2d226c710bc656ce380c621a2b16 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: 26f1fad29ad9 ("New driver: rtl8xxxu (mac80211)")
Cc: stable <stable@vger.kernel.org>     # 4.4
Cc: Jes Sorensen <Jes.Sorensen@redhat.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/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index b2e1523b4dc14a5c8d57bbfe33c4c7c4f57d3ad2..070ea0f456abd61c5e2ae4fff5e692f4d3756902 100644 (file)
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -5921,7 +5921,7 @@ static int rtl8xxxu_parse_usb(struct rtl8xxxu_priv *priv,
        u8 dir, xtype, num;
        int ret = 0;
 
-       host_interface = &interface->altsetting[0];
+       host_interface = interface->cur_altsetting;
        interface_desc = &host_interface->desc;
        endpoints = interface_desc->bNumEndpoints;