[PATCH] staging: gdm724x: gdm_mux: fix use-after-free on module unload

[Johan Hovold]

Make sure to deregister the USB driver before releasing the tty driver
to avoid use-after-free in the USB disconnect callback where the tty
devices are deregistered.

Fixes: 61e121047645 ("staging: gdm7240: adding LTE USB driver")
Cc: stable <stable@xxxxxxxxxxxxxxx>     # 3.12
Cc: Won Kang <wkang77@xxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
 drivers/staging/gdm724x/gdm_mux.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/staging/gdm724x/gdm_mux.c b/drivers/staging/gdm724x/gdm_mux.c
index 400969170d1c..f03e43b1b5f6 100644
--- a/drivers/staging/gdm724x/gdm_mux.c
+++ b/drivers/staging/gdm724x/gdm_mux.c
@@ -664,9 +664,8 @@ static int __init gdm_usb_mux_init(void)
 
 static void __exit gdm_usb_mux_exit(void)
 {
-	unregister_lte_tty_driver();
-
 	usb_deregister(&gdm_mux_driver);
+	unregister_lte_tty_driver();
 }
 
 module_init(gdm_usb_mux_init);
-- 
2.12.2