linux-kernel - [PATCH 1/2] USB: serial: console: fix use-after-free on disconnect

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20171004090113.24218-2-johan@kernel.org>
Date:   Wed,  4 Oct 2017 11:01:12 +0200
From:   Johan Hovold <johan@...nel.org>
To:     linux-usb@...r.kernel.org
Cc:     Andrey Konovalov <andreyknvl@...gle.com>,
        linux-kernel@...r.kernel.org, Johan Hovold <johan@...nel.org>,
        stable <stable@...r.kernel.org>
Subject: [PATCH 1/2] USB: serial: console: fix use-after-free on disconnect

A clean-up patch removing 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@...r.kernel.org>     # 4.11
Reported-by: Andrey Konovalov <andreyknvl@...gle.com>
Signed-off-by: Johan Hovold <johan@...nel.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