rtl8xxxu: fix interface sanity check

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

diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index 73fc5952fd371c7a2d949d76e72b382ba96fc920..63f37fa72e4babad190cab1ffcc893aa13c7d4a8 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;