patch "USB: serial: console: fix use-after-free on disconnect" added to usb-linus

patch "USB: serial: console: fix use-after-free on disconnect" added to usb-linus

[gregkh]

This is a note to let you know that I've just added the patch titled

    USB: serial: console: fix use-after-free on disconnect

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


>From bd998c2e0df0469707503023d50d46cf0b10c787 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Wed, 4 Oct 2017 11:01:12 +0200
Subject: USB: serial: console: fix use-after-free on disconnect

A clean-up patch removing two redundant NULL-checks from the console
disconnect handler inadvertently also removed a third check. This could
lead to the struct usb_serial being prematurely freed by the console
code when a driver accepts but does not register any ports for an
interface which also lacks endpoint descriptors.

Fixes: 0e517c93dc02 ("USB: serial: console: clean up sanity checks")
Cc: stable <stable@vger.kernel.org>     # 4.11
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/serial/console.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/serial/console.c b/drivers/usb/serial/console.c
index fdf89800ebc3..ed8ba3ef5c79 100644
--- a/drivers/usb/serial/console.c
+++ b/drivers/usb/serial/console.c
@@ -265,7 +265,7 @@ static struct console usbcons = {
 
 void usb_serial_console_disconnect(struct usb_serial *serial)
 {
-	if (serial->port[0] == usbcons_info.port) {
+	if (serial->port[0] && serial->port[0] == usbcons_info.port) {
 		usb_serial_console_exit();
 		usb_serial_put(serial);
 	}
-- 
2.14.2