[media] uvcvideo: Fix race-related crash in uvc_video_clock_update()
authorLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Tue, 27 Mar 2012 08:51:00 +0000 (05:51 -0300)
committerMauro Carvalho Chehab <mchehab@redhat.com>
Mon, 9 Apr 2012 13:15:28 +0000 (10:15 -0300)
commited0ee0ce0a3224dab5caa088a5f8b6df25924276
tree710fb6f35ee2bf9e0ccd1aa8d3318ebb2b677f7f
parentd3a92d624806a7964ca3122f917ff2ba69e4cdd8
[media] uvcvideo: Fix race-related crash in uvc_video_clock_update()

The driver frees the clock samples buffer before stopping the video
buffers queue. If a DQBUF call arrives in-between,
uvc_video_clock_update() will be called with a NULL clock samples
buffer, leading to a crash. This occurs very frequently when using the
webcam with the flash browser plugin.

Move clock initialization/cleanup to uvc_video_enable() in order to free
the clock samples buffer after the queue is stopped. Make sure the clock
is reset at resume time to avoid miscalculating timestamps.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
drivers/media/video/uvc/uvc_video.c