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Commit f7d7aedf authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
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USB: serial/keyspan_pda, fix potential tty NULL dereferences 



Make sure that we check the return value of tty_port_tty_get.
Sometimes it may return NULL and we later dereference that.

There are several places to check. For easier handling,
tty_port_tty_get is moved directly to the palce where needed in
keyspan_pda_rx_interrupt.

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 7adc14b1

drivers/usb/serial/keyspan_pda.c

+8 −7
Original line number Diff line number Diff line
@@ -173,6 +173,7 @@ static void keyspan_pda_wakeup_write(struct work_struct *work) 
		container_of(work, struct keyspan_pda_private, wakeup_work);

	struct usb_serial_port *port = priv->port;

	struct tty_struct *tty = tty_port_tty_get(&port->port);

	if (tty)

		tty_wakeup(tty);

	tty_kref_put(tty);

}
@@ -206,7 +207,7 @@ static void keyspan_pda_request_unthrottle(struct work_struct *work) 
static void keyspan_pda_rx_interrupt(struct urb *urb)

{

	struct usb_serial_port *port = urb->context;

	struct tty_struct *tty = tty_port_tty_get(&port->port);

	struct tty_struct *tty;

	unsigned char *data = urb->transfer_buffer;

	int retval;

	int status = urb->status;
@@ -223,7 +224,7 @@ static void keyspan_pda_rx_interrupt(struct urb *urb) 
		/* this urb is terminated, clean up */

		dbg("%s - urb shutting down with status: %d",

		    __func__, status);

		goto out;

		return;

	default:

		dbg("%s - nonzero urb status received: %d",

		    __func__, status);
@@ -233,12 +234,14 @@ static void keyspan_pda_rx_interrupt(struct urb *urb) 
	/* see if the message is data or a status interrupt */

	switch (data[0]) {

	case 0:

		tty = tty_port_tty_get(&port->port);

		 /* rest of message is rx data */

		if (urb->actual_length) {

		if (tty && urb->actual_length) {

			tty_insert_flip_string(tty, data + 1,

						urb->actual_length - 1);

			tty_flip_buffer_push(tty);

		}

		tty_kref_put(tty);

		break;

	case 1:

		/* status interrupt */
@@ -265,8 +268,6 @@ exit: 
		dev_err(&port->dev,

			"%s - usb_submit_urb failed with result %d",

			__func__, retval);

out:

	tty_kref_put(tty);		     

}