[PATCH 3.16 089/134] staging: gdm724x: gdm_mux: fix use-after-free on module unload

Ben Hutchings
2017-08-18T13:15:49Z

From: Johan Hovold <johan@kernel.org>

commit b58f45c8fc301fe83ee28cad3e64686c19e78f1c upstream.

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: Won Kang <wkang77@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/staging/gdm724x/gdm_mux.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/staging/gdm724x/gdm_mux.c
+++ b/drivers/staging/gdm724x/gdm_mux.c
@@ -666,9 +666,8 @@ 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);