Re: [PATCH 2/2] staging: media: tegra-video: add missing error checks in vi_tpg_fmts_bitmap_init()

[Dan Carpenter <error27@gmail.com>]

On Sat, Apr 11, 2026 at 11:10:05PM +0200, Alexandru Hossu wrote:
> tegra_get_format_idx_by_code() returns -1 when the requested format is
> not found in the SoC format table. vi_tpg_fmts_bitmap_init() does not
> check this return value before passing it to bitmap_set(). A negative
> index converted to unsigned would result in an out-of-bounds memory
> access, corrupting adjacent kernel memory.
> 
> Add WARN_ON() guards so that any future SoC addition or Kconfig change
> that exposes this path fails loudly rather than silently corrupting memory.
> 
> Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
> ---
>  drivers/staging/media/tegra-video/vi.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/staging/media/tegra-video/vi.c b/drivers/staging/media/tegra-video/vi.c
> index afc7327ef318..e6416ea8503e 100644
> --- a/drivers/staging/media/tegra-video/vi.c
> +++ b/drivers/staging/media/tegra-video/vi.c
> @@ -1025,11 +1025,15 @@ static void vi_tpg_fmts_bitmap_init(struct tegra_vi_channel *chan)
>  
>  	index = tegra_get_format_idx_by_code(chan->vi,
>  					     MEDIA_BUS_FMT_SRGGB10_1X10, 0);

This will only fail if we can't find MEDIA_BUS_FMT_SRGGB10_1X10 in
the tegra210_video_formats array.  The commit message makes it sound
like this fixes a memory corruption bug, but it can only happen if
the memory is already corrupted beyond hope.

Please write the commit message to be more clear that this is not
a real issue in existing kernels.

regards,
dan carpenter