[FFmpeg-devel] [PATCH] avcodec/mpeg12dec: Fix uninitialized data in fate-sub-cc-scte20

[Carl Eugen Hoyos]

Am Sa., 27. Juni 2020 um 17:46 Uhr schrieb <lance.lmwang at gmail.com>:
>
> From: Limin Wang <lance.lmwang at gmail.com>
>
> The issue is introduced from a705bcd763e344fa, please tested with below command line:
> make V=1 fate-sub-cc-scte20 TARGET_EXEC="valgrind --error-exitcode=1"
>
> Reported-by:   Martin Storsjö <martin at martin.st>
> Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
> ---
>  libavcodec/mpeg12dec.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/libavcodec/mpeg12dec.c b/libavcodec/mpeg12dec.c
> index f0f92ac..2562027 100644
> --- a/libavcodec/mpeg12dec.c
> +++ b/libavcodec/mpeg12dec.c
> @@ -2276,6 +2276,8 @@ static int mpeg_decode_a53_cc(AVCodecContext *avctx,
>              if (ret >= 0) {
>                  uint8_t field, cc1, cc2;
>                  uint8_t *cap = s1->a53_buf_ref->data;
> +

> +                memset(s1->a53_buf_ref->data + old_size, 0, cc_count * UINT64_C(3));

Why is the promotion (?) to uint64 useful?

Carl Eugen