V4L/DVB (11945): uvcvideo: Don't accept to change the format when buffers are allocated.
Setting a new frame format or size will likely change the buffer size required
to store a complete video frame. To avoid a buffer overflow, don't allow
VIDIOC_S_FMT calls when video buffers are already allocated.
Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/uvc/uvc_queue.c b/drivers/media/video/uvc/uvc_queue.c
index 0155752..f854698 100644
--- a/drivers/media/video/uvc/uvc_queue.c
+++ b/drivers/media/video/uvc/uvc_queue.c
@@ -172,6 +172,20 @@
return 0;
}
+/*
+ * Check if buffers have been allocated.
+ */
+int uvc_queue_allocated(struct uvc_video_queue *queue)
+{
+ int allocated;
+
+ mutex_lock(&queue->mutex);
+ allocated = queue->count != 0;
+ mutex_unlock(&queue->mutex);
+
+ return allocated;
+}
+
static void __uvc_query_buffer(struct uvc_buffer *buf,
struct v4l2_buffer *v4l2_buf)
{