blob: 6cb7b922687f50741aa2ebe63779bf8ee8bfa3ef [file] [log] [blame]
From 9e5dba85788c9a9c9cc1c5119cccb3c44572c573 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Fri, 11 Oct 2019 11:57:35 +0200
Subject: [PATCH] USB: serial: ti_usb_3410_5052: fix port-close races
commit 6f1d1dc8d540a9aa6e39b9cb86d3a67bbc1c8d8d upstream.
Fix races between closing a port and opening or closing another port on
the same device which could lead to a failure to start or stop the
shared interrupt URB. The latter could potentially cause a
use-after-free or worse in the completion handler on driver unbind.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c
index dd0ad67aa71e..9174ba2e06da 100644
--- a/drivers/usb/serial/ti_usb_3410_5052.c
+++ b/drivers/usb/serial/ti_usb_3410_5052.c
@@ -776,7 +776,6 @@ static void ti_close(struct usb_serial_port *port)
struct ti_port *tport;
int port_number;
int status;
- int do_unlock;
unsigned long flags;
tdev = usb_get_serial_data(port->serial);
@@ -800,16 +799,13 @@ static void ti_close(struct usb_serial_port *port)
"%s - cannot send close port command, %d\n"
, __func__, status);
- /* if mutex_lock is interrupted, continue anyway */
- do_unlock = !mutex_lock_interruptible(&tdev->td_open_close_lock);
+ mutex_lock(&tdev->td_open_close_lock);
--tport->tp_tdev->td_open_port_count;
- if (tport->tp_tdev->td_open_port_count <= 0) {
+ if (tport->tp_tdev->td_open_port_count == 0) {
/* last port is closed, shut down interrupt urb */
usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
- tport->tp_tdev->td_open_port_count = 0;
}
- if (do_unlock)
- mutex_unlock(&tdev->td_open_close_lock);
+ mutex_unlock(&tdev->td_open_close_lock);
}
--
2.7.4