[34-longterm 216/247] uvcvideo: Fix uvc_fixup_video_ctrl() format search

Paul Gortmaker
2011-06-23T17:48:47Z

From: Stephan Lachowsky <stephan.lachowsky@maxim-ic.com>

-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.
-------------------

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: Paul Gortmaker <paul.gortmaker@windriver.com>
---
drivers/media/video/uvc/uvc_video.c | 14 +++++++++-----
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 821a996..687c970 100644
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -65,15 +65,19 @@ 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) {
--
1.7.4.4