USB: f81232: 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/f81232.c b/drivers/usb/serial/f81232.c
index b1b2dc6..a172ad5 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -47,7 +47,6 @@
struct f81232_private {
spinlock_t lock;
- wait_queue_head_t delta_msr_wait;
u8 line_control;
u8 line_status;
};
@@ -111,7 +110,7 @@
line_status = priv->line_status;
priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
spin_unlock_irqrestore(&priv->lock, flags);
- wake_up_interruptible(&priv->delta_msr_wait);
+ wake_up_interruptible(&port->delta_msr_wait);
if (!urb->actual_length)
return;
@@ -256,11 +255,14 @@
spin_unlock_irqrestore(&priv->lock, flags);
while (1) {
- 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);
@@ -322,7 +324,6 @@
return -ENOMEM;
spin_lock_init(&priv->lock);
- init_waitqueue_head(&priv->delta_msr_wait);
usb_set_serial_port_data(port, priv);