USB: pl2303: fix use-after-free in TIOCMIWAIT
commit 40509ca982c00c4b70fc00be887509feca0bff15 upstream.
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.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Yang Yingliang <yangyingliang@huawei.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 1dcccd4..2d5072b 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -149,7 +149,6 @@
struct pl2303_private {
spinlock_t lock;
- wait_queue_head_t delta_msr_wait;
u8 line_control;
u8 line_status;
enum pl2303_type type;
@@ -203,7 +202,6 @@
if (!priv)
goto cleanup;
spin_lock_init(&priv->lock);
- init_waitqueue_head(&priv->delta_msr_wait);
priv->type = type;
usb_set_serial_port_data(serial->port[i], priv);
}
@@ -595,11 +593,14 @@
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);
@@ -721,7 +722,7 @@
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)
@@ -788,7 +789,7 @@
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;