[PATCH 3.10 022/139] serial: ifx6x60: fix use-after-free on module unload

[Willy Tarreau]

From: Johan Hovold <johan@xxxxxxxxxx>

commit 1e948479b3d63e3ac0ecca13cbf4921c7d17c168 upstream.

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

Fixes: 72d4724ea54c ("serial: ifx6x60: Add modem power off function in the platform reboot process")
Cc: stable <stable@xxxxxxxxxxxxxxx>     
Cc: Jun Chen <jun.d.chen@xxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Willy Tarreau <w@xxxxxx>
---
 drivers/tty/serial/ifx6x60.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/serial/ifx6x60.c b/drivers/tty/serial/ifx6x60.c
index 8b1534c..be3dc75 100644
--- a/drivers/tty/serial/ifx6x60.c
+++ b/drivers/tty/serial/ifx6x60.c
@@ -1379,9 +1379,9 @@ static struct spi_driver ifx_spi_driver = {
 static void __exit ifx_spi_exit(void)
 {
 	/* unregister */
+	spi_unregister_driver((void *)&ifx_spi_driver);
 	tty_unregister_driver(tty_drv);
 	put_tty_driver(tty_drv);
-	spi_unregister_driver((void *)&ifx_spi_driver);
 	unregister_reboot_notifier(&ifx_modem_reboot_notifier_block);
 }
 
-- 
2.8.0.rc2.1.gbe9624a