[media] uvcvideo: Fix uvc_fixup_video_ctrl() format search

The scheme used to index format in uvc_fixup_video_ctrl() is not robust:
format index is based on descriptor ordering, which does not necessarily
match bFormatIndex ordering.  Searching for first matching format will
prevent uvc_fixup_video_ctrl() from using the wrong format/frame to make
adjustments.

Signed-off-by: Stephan Lachowsky <stephan.lachowsky@maxim-ic.com>
Cc: stable@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index 5673d67..545c029 100644 (file)
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -89,15 +89,19 @@ int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
 static void uvc_fixup_video_ctrl(struct uvc_streaming *stream,
        struct uvc_streaming_control *ctrl)
 {
-       struct uvc_format *format;
+       struct uvc_format *format = NULL;
        struct uvc_frame *frame = NULL;
        unsigned int i;
 
-       if (ctrl->bFormatIndex <= 0 ||
-           ctrl->bFormatIndex > stream->nformats)
-               return;
+       for (i = 0; i < stream->nformats; ++i) {
+               if (stream->format[i].index == ctrl->bFormatIndex) {
+                       format = &stream->format[i];
+                       break;
+               }
+       }
 
-       format = &stream->format[ctrl->bFormatIndex - 1];
+       if (format == NULL)
+               return;
 
        for (i = 0; i < format->nframes; ++i) {
                if (format->frame[i].bFrameIndex == ctrl->bFrameIndex) {