[FFmpeg-devel] [PATCH v1] avcodec/cbs_vp8: Use little endian in fixed()

[Ronald S. Bultje]

Hi,

On Wed, Jan 24, 2024 at 7:54 PM Dai, Jianhui J <
jianhui.j.dai-at-intel.com at ffmpeg.org> wrote:

> This commit adds value range checks to cbs_vp8_read_unsigned_le,
> migrates fixed() to use it, and enforces little-endian consistency for
> all read methods.
>
> Signed-off-by: Jianhui Dai <jianhui.j.dai at intel.com>
> ---
>  libavcodec/cbs_vp8.c | 23 +++++++++++++++++------
>  1 file changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/libavcodec/cbs_vp8.c b/libavcodec/cbs_vp8.c
> index 065156c248..7a0752019b 100644
> --- a/libavcodec/cbs_vp8.c
> +++ b/libavcodec/cbs_vp8.c
> @@ -181,9 +181,11 @@ static int cbs_vp8_bool_decoder_read_signed(
>      return 0;
>  }
>
> -static int cbs_vp8_read_unsigned_le(CodedBitstreamContext *ctx,
> GetBitContext *gbc,
> -                                 int width, const char *name,
> -                                 const int *subscripts, uint32_t
> *write_to)
> +static int cbs_vp8_read_unsigned_le(CodedBitstreamContext *ctx,
> +                                    GetBitContext *gbc, int width,
> +                                    const char *name, const int
> *subscripts,
> +                                    uint32_t *write_to, uint32_t
> range_min,
> +                                    uint32_t range_max)
>  {
>      int32_t value;
>
> @@ -200,6 +202,14 @@ static int
> cbs_vp8_read_unsigned_le(CodedBitstreamContext *ctx, GetBitContext *g
>
>      CBS_TRACE_READ_END();
>
> +    if (value < range_min || value > range_max) {
> +        av_log(ctx->log_ctx, AV_LOG_ERROR,
> +               "%s out of range: "
> +               "%" PRIu32 ", but must be in [%" PRIu32 ",%" PRIu32 "].\n",
> +               name, value, range_min, range_max);
> +        return AVERROR_INVALIDDATA;
> +    }
> +
>      *write_to = value;
>      return 0;
>  }
> @@ -246,15 +256,16 @@ static int
> cbs_vp8_read_unsigned_le(CodedBitstreamContext *ctx, GetBitContext *g
>      do { \
>          uint32_t value; \
>          CHECK(cbs_vp8_read_unsigned_le(ctx, rw, width, #name, \
> -                                    SUBSCRIPTS(subs, __VA_ARGS__),
> &value)); \
> +                                       SUBSCRIPTS(subs, __VA_ARGS__),
> &value, \
> +                                       0, MAX_UINT_BITS(width))); \
>          current->name = value; \
>      } while (0)
>
>  #define fixed(width, name, value) \
>      do { \
>          uint32_t fixed_value; \
> -        CHECK(ff_cbs_read_unsigned(ctx, rw, width, #name, 0,
> &fixed_value, \
> -                                   value, value)); \
> +        CHECK(cbs_vp8_read_unsigned_le(ctx, rw, width, #name, 0,
> &fixed_value, \
> +                                       value, value)); \
>      } while (0)
>
>  #define bc_unsigned_subs(width, prob, enable_trace, name, subs, ...) \
> --
> 2.25.1
>

Merged.

Ronald