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>

1 files changed, 8 insertions, 7 deletions

diff --git a/drivers/staging/line6/toneport.c b/drivers/staging/line6/toneport.c
index 69437158d383..660dc3f2aa61 100644
--- 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);