USB: pl2303: 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/pl2303.c b/drivers/usb/serial/pl2303.c
index 54adc91..3b10018 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -139,7 +139,6 @@
struct pl2303_private {
spinlock_t lock;
- wait_queue_head_t delta_msr_wait;
u8 line_control;
u8 line_status;
};
@@ -233,7 +232,6 @@
return -ENOMEM;
spin_lock_init(&priv->lock);
- init_waitqueue_head(&priv->delta_msr_wait);
usb_set_serial_port_data(port, priv);
@@ -607,11 +605,14 @@
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);
@@ -719,7 +720,7 @@
spin_unlock_irqrestore(&priv->lock, flags);
if (priv->line_status & UART_BREAK_ERROR)
usb_serial_handle_break(port);
- wake_up_interruptible(&priv->delta_msr_wait);
+ wake_up_interruptible(&port->delta_msr_wait);
tty = tty_port_tty_get(&port->port);
if (!tty)
@@ -783,7 +784,7 @@
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;