From 2f2f3ffa761793f2db2f3b0bc6476a069061cb9c Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Thu, 19 Sep 2019 14:12:34 +0200
Subject: [PATCH] ieee802154: atusb: fix use-after-free at disconnect

commit 7fd25e6fc035f4b04b75bca6d7e8daa069603a76 upstream.

The disconnect callback was accessing the hardware-descriptor private
data after having having freed it.

Fixes: 7490b008d123 ("ieee802154: add support for atusb transceiver")
Cc: stable <stable@vger.kernel.org>     # 4.2
Cc: Alexander Aring <alex.aring@gmail.com>
Reported-by: syzbot+f4509a9138a1472e7e80@syzkaller.appspotmail.com
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ieee802154/atusb.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ieee802154/atusb.c b/drivers/net/ieee802154/atusb.c
index f186e0460cde..12df6cfb423a 100644
--- a/drivers/net/ieee802154/atusb.c
+++ b/drivers/net/ieee802154/atusb.c
@@ -838,10 +838,11 @@ static void atusb_disconnect(struct usb_interface *interface)
 
 	ieee802154_unregister_hw(atusb->hw);
 
+	usb_put_dev(atusb->usb_dev);
+
 	ieee802154_free_hw(atusb->hw);
 
 	usb_set_intfdata(interface, NULL);
-	usb_put_dev(atusb->usb_dev);
 
 	pr_debug("atusb_disconnect done\n");
 }