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: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index 554a869..7b690f3 100644
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -173,7 +173,8 @@
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);
- tty_wakeup(tty);
+ if (tty)
+ tty_wakeup(tty);
tty_kref_put(tty);
}
@@ -206,7 +207,7 @@
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 @@
/* 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 @@
/* see if the message is data or a status interrupt */
switch (data[0]) {
case 0:
- /* rest of message is rx data */
- if (urb->actual_length) {
+ tty = tty_port_tty_get(&port->port);
+ /* rest of message is rx data */
+ 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 @@
dev_err(&port->dev,
"%s - usb_submit_urb failed with result %d",
__func__, retval);
-out:
- tty_kref_put(tty);
}