[PATCH] TTY: io_ti, stop dereferencing potential NULL

From: Jiri Slaby
Date: Thu Apr 04 2013 - 16:41:16 EST


tty_port_tty_get might return a tty which is NULL. But it is
dereferenced unconditionally in edge_send. Stop dereferencing that by
sending usb_serial_port pointer around.

Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Cc: Johan Hovold <jhovold@xxxxxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx
---
drivers/usb/serial/io_ti.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index 0ccc422..f2a1601 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -206,7 +206,7 @@ static int restart_read(struct edgeport_port *edge_port);

static void edge_set_termios(struct tty_struct *tty,
struct usb_serial_port *port, struct ktermios *old_termios);
-static void edge_send(struct tty_struct *tty);
+static void edge_send(struct usb_serial_port *port, struct tty_struct *tty);

/* sysfs attributes */
static int edge_create_sysfs_attrs(struct usb_serial_port *port);
@@ -1712,7 +1712,7 @@ static void edge_bulk_out_callback(struct urb *urb)

/* send any buffered data */
tty = tty_port_tty_get(&port->port);
- edge_send(tty);
+ edge_send(port, tty);
tty_kref_put(tty);
}

@@ -1940,14 +1940,13 @@ static int edge_write(struct tty_struct *tty, struct usb_serial_port *port,

count = kfifo_in_locked(&edge_port->write_fifo, data, count,
&edge_port->ep_lock);
- edge_send(tty);
+ edge_send(port, tty);

return count;
}

-static void edge_send(struct tty_struct *tty)
+static void edge_send(struct usb_serial_port *port, struct tty_struct *tty)
{
- struct usb_serial_port *port = tty->driver_data;
int count, result;
struct edgeport_port *edge_port = usb_get_serial_port_data(port);
unsigned long flags;
--
1.8.2


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/