Patchwork [Precise,SRU,media] au0828: fix case where STREAMOFF being called on stopped stream causes BUG()

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Submitter Tim Gardner
Date Oct. 11, 2012, 7:18 p.m.
Message ID <1349983124-86296-1-git-send-email-tim.gardner@canonical.com>
Download mbox | patch
Permalink /patch/190980/
State New
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Comments

Tim Gardner - Oct. 11, 2012, 7:18 p.m.
From: Devin Heitmueller <dheitmueller@kernellabs.com>

BugLink: http://bugs.launchpad.net/bugs/1062917

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>
(cherry picked from commit a595c1ce4c9d572cf53513570b9f1a263d7867f2)

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
---
 drivers/media/video/au0828/au0828-video.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)
Tim Gardner - Oct. 11, 2012, 7:38 p.m.
Also applies to Quantal
Herton Ronaldo Krzesinski - Oct. 11, 2012, 7:50 p.m.

Tim Gardner - Oct. 11, 2012, 8:14 p.m.

Patch

diff --git a/drivers/media/video/au0828/au0828-video.c b/drivers/media/video/au0828/au0828-video.c
index 0b3e481..eab0641 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;