[PATCH 4.9 12/80] staging: gdm724x: gdm_mux: fix use-after-free on module unload

From: Greg Kroah-Hartman
Date: Thu May 18 2017 - 07:29:23 EST

4.9-stable review patch. If anyone has any objections, please let me know.


From: Johan Hovold <johan@xxxxxxxxxx>

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@xxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

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
@@ -664,9 +664,8 @@ static int __init gdm_usb_mux_init(void)

static void __exit gdm_usb_mux_exit(void)
- unregister_lte_tty_driver();
+ unregister_lte_tty_driver();