ieee802154: atusb: fix use-after-free at disconnect

BugLink: https://bugs.launchpad.net/bugs/1849576
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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/net/ieee802154/atusb.c b/drivers/net/ieee802154/atusb.c
index 9fb9b565a002ff7c2e9f6a06c4ef6b9c4d640266..1da9a1c1f689cae69931fc9af5f7ceb569b0a2e9 100644 (file)
--- a/drivers/net/ieee802154/atusb.c
+++ b/drivers/net/ieee802154/atusb.c
@@ -1140,10 +1140,11 @@ 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("%s done\n", __func__);
 }