From 40509ca982c00c4b70fc00be887509feca0bff15 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 19 Mar 2013 09:21:22 +0100 Subject: [PATCH] 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 Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/pl2303.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c index 54adc9125e5..3b10018d89a 100644 --- a/drivers/usb/serial/pl2303.c +++ b/drivers/usb/serial/pl2303.c @@ -139,7 +139,6 @@ struct pl2303_serial_private { struct pl2303_private { spinlock_t lock; - wait_queue_head_t delta_msr_wait; u8 line_control; u8 line_status; }; @@ -233,7 +232,6 @@ static int pl2303_port_probe(struct usb_serial_port *port) 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 @@ static int wait_modem_info(struct usb_serial_port *port, unsigned int arg) 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 @@ static void pl2303_update_line_status(struct usb_serial_port *port, 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 @@ static void pl2303_process_read_urb(struct urb *urb) 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; -- 2.41.0