[PATCH 20/21] USB: ssu100: fix use-after-free in TIOCMIWAIT

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Use the port wait queue and make sure to check the serial disconnected
flag before accessing private port data after waking up.

This is is needed as the private port data (including the wait queue
itself) can be gone when waking up after a disconnect.

Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
---
 drivers/usb/serial/ssu100.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/serial/ssu100.c b/drivers/usb/serial/ssu100.c
index b57cf84..4b2a197 100644
--- a/drivers/usb/serial/ssu100.c
+++ b/drivers/usb/serial/ssu100.c
@@ -61,7 +61,6 @@ struct ssu100_port_private {
 	spinlock_t status_lock;
 	u8 shadowLSR;
 	u8 shadowMSR;
-	wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */
 	struct async_icount icount;
 };
 
@@ -355,8 +354,9 @@ static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
 	spin_unlock_irqrestore(&priv->status_lock, flags);
 
 	while (1) {
-		wait_event_interruptible(priv->delta_msr_wait,
-					 ((priv->icount.rng != prev.rng) ||
+		wait_event_interruptible(port->delta_msr_wait,
+					 (port->serial->disconnected ||
+					  (priv->icount.rng != prev.rng) ||
 					  (priv->icount.dsr != prev.dsr) ||
 					  (priv->icount.dcd != prev.dcd) ||
 					  (priv->icount.cts != prev.cts)));
@@ -364,6 +364,9 @@ static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
 		if (signal_pending(current))
 			return -ERESTARTSYS;
 
+		if (port->serial->disconnected)
+			return -EIO;
+
 		spin_lock_irqsave(&priv->status_lock, flags);
 		cur = priv->icount;
 		spin_unlock_irqrestore(&priv->status_lock, flags);
@@ -445,7 +448,6 @@ static int ssu100_port_probe(struct usb_serial_port *port)
 		return -ENOMEM;
 
 	spin_lock_init(&priv->status_lock);
-	init_waitqueue_head(&priv->delta_msr_wait);
 
 	usb_set_serial_port_data(port, priv);
 
@@ -537,7 +539,7 @@ static void ssu100_update_msr(struct usb_serial_port *port, u8 msr)
 			priv->icount.dcd++;
 		if (msr & UART_MSR_TERI)
 			priv->icount.rng++;
-		wake_up_interruptible(&priv->delta_msr_wait);
+		wake_up_interruptible(&port->delta_msr_wait);
 	}
 }
 
-- 
1.8.1.5

--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]