[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>

1 files changed, 9 insertions, 5 deletions

diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index 5673d673504b..545c0294813d 100644
--- 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) {