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authorJohan Hovold <jhovold@gmail.com>2013-03-19 09:21:23 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-03-21 15:59:05 -0700
commit69f87f40d2b98e8b4ab82a121fd2bd584690b887 (patch)
tree51f4e310d5db5cd0bc727a2554f7c90bcba22c6c /drivers/usb
parent40509ca982c00c4b70fc00be887509feca0bff15 (diff)
downloadlinux-69f87f40d2b98e8b4ab82a121fd2bd584690b887.tar.bz2
USB: quatech2: 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>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/serial/quatech2.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/usb/serial/quatech2.c b/drivers/usb/serial/quatech2.c
index d643a4d4d770..75f125ddb0c9 100644
--- a/drivers/usb/serial/quatech2.c
+++ b/drivers/usb/serial/quatech2.c
@@ -128,7 +128,6 @@ struct qt2_port_private {
u8 shadowLSR;
u8 shadowMSR;
- wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */
struct async_icount icount;
struct usb_serial_port *port;
@@ -506,8 +505,9 @@ static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
spin_unlock_irqrestore(&priv->lock, flags);
while (1) {
- wait_event_interruptible(priv->delta_msr_wait,
- ((priv->icount.rng != prev.rng) ||
+ wait_event_interruptible(port->delta_msr_wait,
+ (port->serial->disconnected ||
+ (priv->icount.rng != prev.rng) ||
(priv->icount.dsr != prev.dsr) ||
(priv->icount.dcd != prev.dcd) ||
(priv->icount.cts != prev.cts)));
@@ -515,6 +515,9 @@ static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
if (signal_pending(current))
return -ERESTARTSYS;
+ if (port->serial->disconnected)
+ return -EIO;
+
spin_lock_irqsave(&priv->lock, flags);
cur = priv->icount;
spin_unlock_irqrestore(&priv->lock, flags);
@@ -827,7 +830,6 @@ static int qt2_port_probe(struct usb_serial_port *port)
spin_lock_init(&port_priv->lock);
spin_lock_init(&port_priv->urb_lock);
- init_waitqueue_head(&port_priv->delta_msr_wait);
port_priv->port = port;
port_priv->write_urb = usb_alloc_urb(0, GFP_KERNEL);
@@ -970,7 +972,7 @@ static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch)
if (newMSR & UART_MSR_TERI)
port_priv->icount.rng++;
- wake_up_interruptible(&port_priv->delta_msr_wait);
+ wake_up_interruptible(&port->delta_msr_wait);
}
}