staging: line6: toneport.c: Fix for possible null pointer dereference

The NULL check was done to late, and there it was a risk
of a possible null pointer dereference.

This was partially found by using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/drivers/staging/line6/toneport.c b/drivers/staging/line6/toneport.c
index 6943715..660dc3f 100644 (file)
--- a/drivers/staging/line6/toneport.c
+++ b/drivers/staging/line6/toneport.c
@@ -433,12 +433,16 @@ void line6_toneport_reset_resume(struct usb_line6_toneport *toneport)
 void line6_toneport_disconnect(struct usb_interface *interface)
 {
        struct usb_line6_toneport *toneport;
+       struct snd_line6_pcm *line6pcm;
        u16 idProduct;
 
        if (interface == NULL)
                return;
 
        toneport = usb_get_intfdata(interface);
+       if (NULL == toneport)
+               return;
+
        del_timer_sync(&toneport->timer);
        idProduct = le16_to_cpu(toneport->line6.usbdev->descriptor.idProduct);
 
@@ -447,13 +451,10 @@ void line6_toneport_disconnect(struct usb_interface *interface)
                device_remove_file(&interface->dev, &dev_attr_led_green);
        }
 
-       if (toneport != NULL) {
-               struct snd_line6_pcm *line6pcm = toneport->line6.line6pcm;
-
-               if (line6pcm != NULL) {
-                       line6_pcm_release(line6pcm, LINE6_BITS_PCM_MONITOR);
-                       line6_pcm_disconnect(line6pcm);
-               }
+       line6pcm = toneport->line6.line6pcm;
+       if (line6pcm != NULL) {
+               line6_pcm_release(line6pcm, LINE6_BITS_PCM_MONITOR);
+               line6_pcm_disconnect(line6pcm);
        }
 
        toneport_destruct(interface);