[PATCH 6.1 208/609] media: tegra-video: vi: fix invalid u32 return value in format lookup

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Hungyu Lin <[email protected]>

commit d5b50055338e131a1a99f923ebb0361974a00f36 upstream.

tegra_get_format_fourcc_by_idx() returns a u32 but uses -EINVAL to
signal an out-of-bounds index. This results in a large unsigned
value being returned, which may be interpreted as a valid fourcc.

Returning 0 is not a valid fourcc either. This condition should
never happen, so use WARN_ON_ONCE() to catch unexpected out-of-bounds
access and return a valid fallback format instead.

Suggested-by: Hans Verkuil <[email protected]>
Fixes: 3d8a97eabef0 ("media: tegra-video: Add Tegra210 Video input driver")
Cc: [email protected]
Reviewed-by: Luca Ceresoli <[email protected]>
Signed-off-by: Hungyu Lin <[email protected]>
Signed-off-by: Hans Verkuil <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 drivers/staging/media/tegra-video/vi.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/staging/media/tegra-video/vi.c
+++ b/drivers/staging/media/tegra-video/vi.c
@@ -76,8 +76,8 @@ static int tegra_get_format_idx_by_code(
 static u32 tegra_get_format_fourcc_by_idx(struct tegra_vi *vi,
 					  unsigned int index)
 {
-	if (index >= vi->soc->nformats)
-		return -EINVAL;
+	if (WARN_ON_ONCE(index >= vi->soc->nformats))
+		return vi->soc->video_formats[0].fourcc;
 
 	return vi->soc->video_formats[index].fourcc;
 }