Patchwork [102/150] USB: f81232: fix use-after-free in TIOCMIWAIT

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Submitter Luis Henriques
Date March 26, 2013, 3:20 p.m.
Message ID <1364311249-14454-103-git-send-email-luis.henriques@canonical.com>
Download mbox | patch
Permalink /patch/231361/
State New
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Luis Henriques - March 26, 2013, 3:20 p.m.
3.5.7.9 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johan Hovold <jhovold@gmail.com>

commit 508f940f1407656076a2e7d8f7fa059b567ecac2 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ luis: backport to 3.5; adjust context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 drivers/usb/serial/f81232.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

Patch

diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index 499b15f..ea88b47 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -49,7 +49,6 @@  MODULE_DEVICE_TABLE(usb, id_table);
 
 struct f81232_private {
 	spinlock_t lock;
-	wait_queue_head_t delta_msr_wait;
 	u8 line_control;
 	u8 line_status;
 };
@@ -114,7 +113,7 @@  static void f81232_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;
@@ -262,11 +261,14 @@  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);
@@ -329,7 +331,6 @@  static int f81232_startup(struct usb_serial *serial)
 		if (!priv)
 			goto cleanup;
 		spin_lock_init(&priv->lock);
-		init_waitqueue_head(&priv->delta_msr_wait);
 		usb_set_serial_port_data(serial->port[i], priv);
 	}
 	return 0;