USB: spcp8x5: fix use-after-free in TIOCMIWAIT
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@vger.kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/serial/spcp8x5.c b/drivers/usb/serial/spcp8x5.c
index 91ff8e3..549ef68 100644
--- a/drivers/usb/serial/spcp8x5.c
+++ b/drivers/usb/serial/spcp8x5.c
@@ -149,7 +149,6 @@
struct spcp8x5_private {
spinlock_t lock;
enum spcp8x5_type type;
- wait_queue_head_t delta_msr_wait;
u8 line_control;
u8 line_status;
};
@@ -179,7 +178,6 @@
return -ENOMEM;
spin_lock_init(&priv->lock);
- init_waitqueue_head(&priv->delta_msr_wait);
priv->type = type;
usb_set_serial_port_data(port , priv);
@@ -475,7 +473,7 @@
priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
spin_unlock_irqrestore(&priv->lock, flags);
/* wake up the wait for termios */
- wake_up_interruptible(&priv->delta_msr_wait);
+ wake_up_interruptible(&port->delta_msr_wait);
if (!urb->actual_length)
return;
@@ -526,12 +524,15 @@
while (1) {
/* wake up in bulk read */
- interruptible_sleep_on(&priv->delta_msr_wait);
+ interruptible_sleep_on(&port->delta_msr_wait);
/* see if a signal did it */
if (signal_pending(current))
return -ERESTARTSYS;
+ if (port->serial->disconnected)
+ return -EIO;
+
spin_lock_irqsave(&priv->lock, flags);
status = priv->line_status;
spin_unlock_irqrestore(&priv->lock, flags);
