From: Johan Hovold <johan@kernel.org>
Date: Wed, 26 Apr 2017 10:24:21 +0000 (+0200)
Subject: serial: ifx6x60: fix use-after-free on module unload
X-Git-Tag: v4.9.32~96
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=3802abc6e0dfa892d7205fac199b0e2d68cec056;p=users%2Fdwmw2%2Flinux.git

serial: ifx6x60: fix use-after-free on module unload

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: Jun Chen <jun.d.chen@intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/tty/serial/ifx6x60.c b/drivers/tty/serial/ifx6x60.c
index d386346248deb..91d2ddd6ef881 100644
--- a/drivers/tty/serial/ifx6x60.c
+++ b/drivers/tty/serial/ifx6x60.c
@@ -1381,9 +1381,9 @@ static struct spi_driver ifx_spi_driver = {
 static void __exit ifx_spi_exit(void)
 {
 	/* unregister */
+	spi_unregister_driver(&ifx_spi_driver);
 	tty_unregister_driver(tty_drv);
 	put_tty_driver(tty_drv);
-	spi_unregister_driver(&ifx_spi_driver);
 	unregister_reboot_notifier(&ifx_modem_reboot_notifier_block);
 }