net: hso: fix muxed tty registration

commit e8f69b16ee776da88589b5271e3f46020efc8f6c upstream.

If resource allocation and registration fail for a muxed tty device
(e.g. if there are no more minor numbers) the driver should not try to
deregister the never-registered (or already-deregistered) tty.

Fix up the error handling to avoid dereferencing a NULL pointer when
attempting to remove the character device.

Fixes: 72dc1c096c70 ("HSO: add option hso driver")
Cc: stable@vger.kernel.org	# 2.6.27
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index 5066b7bc67da693e3e337191f7bcae89eecbe14d..bde19425e9c10957de9b2cc374bae34d071d2513 100644 (file)
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -2715,14 +2715,14 @@ struct hso_device *hso_create_mux_serial_device(struct usb_interface *interface,
 
        serial = kzalloc(sizeof(*serial), GFP_KERNEL);
        if (!serial)
-               goto exit;
+               goto err_free_dev;
 
        hso_dev->port_data.dev_serial = serial;
        serial->parent = hso_dev;
 
        if (hso_serial_common_create
            (serial, 1, CTRL_URB_RX_SIZE, CTRL_URB_TX_SIZE))
-               goto exit;
+               goto err_free_serial;
 
        serial->tx_data_length--;
        serial->write_data = hso_mux_serial_write_data;
@@ -2738,11 +2738,9 @@ struct hso_device *hso_create_mux_serial_device(struct usb_interface *interface,
        /* done, return it */
        return hso_dev;
 
-exit:
-       if (serial) {
-               tty_unregister_device(tty_drv, serial->minor);
-               kfree(serial);
-       }
+err_free_serial:
+       kfree(serial);
+err_free_dev:
        kfree(hso_dev);
        return NULL;