[PATCH 183/241] [media] au0828: fix case where STREAMOFF being called on stopped stream causes BUG()

[Herton Ronaldo Krzesinski]

3.5.7.2 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Devin Heitmueller <dheitmueller at kernellabs.com>

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 at lwfinger.net>
Reported-by: Jay Harbeston <jharbestonus at gmail.com>
Signed-off-by: Devin Heitmueller <dheitmueller at kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab at redhat.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 drivers/media/video/au0828/au0828-video.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/media/video/au0828/au0828-video.c b/drivers/media/video/au0828/au0828-video.c
index ac3dd73..902825a 100644
--- a/drivers/media/video/au0828/au0828-video.c
+++ b/drivers/media/video/au0828/au0828-video.c
@@ -1692,14 +1692,18 @@ 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;
-- 
1.7.9.5