wifi: at76c50x: fix use after free access in at76_disconnect

[ Upstream commit 27c7e63 ]

The memory pointed to by priv is freed at the end of at76_delete_device
function (using ieee80211_free_hw). But the code then accesses the udev
field of the freed object to put the USB device. This may also lead to a
memory leak of the usb device. Fix this by using udev from interface.

Fixes: 29e20aa ("at76c50x-usb: fix use after free on failure path in at76_probe()")
Signed-off-by: Abdun Nihaal <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Johannes Berg <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>

Author: nifey

drivers/net/wireless/atmel/at76c50x-usb.c

@@ -2552,7 +2552,7 @@ static void at76_disconnect(struct usb_interface *interface)
 
 	wiphy_info(priv->hw->wiphy, "disconnecting\n");
 	at76_delete_device(priv);
-	usb_put_dev(priv->udev);
+	usb_put_dev(interface_to_usbdev(interface));
 	dev_info(&interface->dev, "disconnected\n");
 }