media: au0828: fix case where STREAMOFF being called on stopped stream causes BUG()

commit a595c1ce4c9d572cf53513570b9f1a263d7867f2 upstream.

We weren't checking whether the resource was in use before calling
res_free(), so applications which called STREAMOFF on a v4l2 device that
wasn't already streaming would cause a BUG() to be hit (MythTV).

Reported-by: Larry Finger <larry.finger@lwfinger.net>
Reported-by: Jay Harbeston <jharbestonus@gmail.com>
Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/au0828/au0828-video.c b/drivers/media/video/au0828/au0828-video.c
index c03eb29a9ee6976fba68ae19b8a9dd6ebcb4b6b7..9945aaf1bbabe88f22428a14cc42dee15a86fc2c 100644 (file)
--- a/drivers/media/video/au0828/au0828-video.c
+++ b/drivers/media/video/au0828/au0828-video.c
@@ -1697,14 +1697,18 @@ static int vidioc_streamoff(struct file *file, void *priv,
                        (AUVI_INPUT(i).audio_setup)(dev, 0);
                }
 
-               videobuf_streamoff(&fh->vb_vidq);
-               res_free(fh, AU0828_RESOURCE_VIDEO);
+               if (res_check(fh, AU0828_RESOURCE_VIDEO)) {
+                       videobuf_streamoff(&fh->vb_vidq);
+                       res_free(fh, AU0828_RESOURCE_VIDEO);
+               }
        } else if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE) {
                dev->vbi_timeout_running = 0;
                del_timer_sync(&dev->vbi_timeout);
 
-               videobuf_streamoff(&fh->vb_vbiq);
-               res_free(fh, AU0828_RESOURCE_VBI);
+               if (res_check(fh, AU0828_RESOURCE_VBI)) {
+                       videobuf_streamoff(&fh->vb_vbiq);
+                       res_free(fh, AU0828_RESOURCE_VBI);
+               }
        }
 
        return 0;