uvcvideo: Fix uvc_fixup_video_ctrl() format search

commit 38a66824d96de8aeeb915e6f46f0d3fe55828eb1 upstream.

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>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index 7dcf534a0cf350c28844a766335a3f121b0476c2..253eed80c0a89f19f4283d2346aa7c6e0e39b6ed 100644 (file)
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -64,15 +64,19 @@ 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) {