diff mbox series

[CVE-2017-16525,SRU,Trusty,Zesty,2/2] USB: serial: console: fix use-after-free on disconnect

Message ID 20171208105801.27896-3-po-hsu.lin@canonical.com
State New
Headers show
Series None | expand

Commit Message

Po-Hsu Lin Dec. 8, 2017, 10:58 a.m. UTC 
From: Johan Hovold <johan@kernel.org>

CVE-2017-16525

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>
(backported from commit bd998c2e0df0469707503023d50d46cf0b10c787)
Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com>
---
 drivers/usb/serial/console.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

Comments

Thadeu Lima de Souza Cascardo Dec. 12, 2017, 4:44 p.m. UTC | #1 
Applied to trusty and zesty master-next branches.

Thanks.
Cascardo.

Applied-to: trusty/master-next
Applied-to: zesty/master-next
diff mbox series

Patch

diff --git a/drivers/usb/serial/console.c b/drivers/usb/serial/console.c
index 76062ce..43a862a 100644
--- a/drivers/usb/serial/console.c
+++ b/drivers/usb/serial/console.c
@@ -266,8 +266,7 @@  static struct console usbcons = {
 
 void usb_serial_console_disconnect(struct usb_serial *serial)
 {
-	if (serial && serial->port && serial->port[0]
-				&& serial->port[0] == usbcons_info.port) {
+	if (serial->port[0] && serial->port[0] == usbcons_info.port) {
 		usb_serial_console_exit();
 		usb_serial_put(serial);
 	}