[FFmpeg-devel] [PATCH 1/5] avcodec/utvideodec: fix leaks in decode_plane() and decode_plane10()

[Michael Niedermayer]

On Sun, Jun 29, 2025 at 02:45:22PM +0800, Lidong Yan wrote:
> In decode_plane() and decode_plane10(), both of these two functions use
> build_buff() which allocates memory in vlc and multi. And both of them
> forget to release vlc and multi when build_buff report a symbol to fill
> slices with. Add cleanup label and goto cleanup first before return 0.
> 
> Signed-off-by: Lidong Yan <502024330056 at smail.nju.edu.cn>
> ---
>  libavcodec/utvideodec.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/utvideodec.c b/libavcodec/utvideodec.c
> index 4c0fa2ca67..f15d623462 100644
> --- a/libavcodec/utvideodec.c
> +++ b/libavcodec/utvideodec.c
> @@ -179,7 +179,7 @@ static int decode_plane10(UtvideoContext *c, int plane_no,
>                  dest += stride;
>              }
>          }
> -        return 0;
> +        goto cleanup;
>      }
>  
>      send = 0;
> @@ -216,6 +216,7 @@ static int decode_plane10(UtvideoContext *c, int plane_no,
>                     "%d bits left after decoding slice\n", get_bits_left(&gb));
>      }
>  
> +cleanup:
>      ff_vlc_free(&vlc);
>      ff_vlc_free_multi(&multi);
>  
> @@ -322,7 +323,7 @@ static int decode_plane(UtvideoContext *c, int plane_no,
>                  dest += stride;
>              }
>          }
> -        return 0;
> +        goto cleanup;
>      }
>  
>      src      += 256;
> @@ -361,6 +362,7 @@ static int decode_plane(UtvideoContext *c, int plane_no,
>                     "%d bits left after decoding slice\n", get_bits_left(&gb));
>      }
>  
> +cleanup:
>      ff_vlc_free(&vlc);
>      ff_vlc_free_multi(&multi);

This is not correct

build_huff() does not set these when fsym >= 0

your patch runs free() on random uninitialized variables

before submitting memleak fixes, please verify that
1. there is actually a leak
2. your patch does not introduce a new anomaly

thx

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Does the universe only have a finite lifespan? No, its going to go on
forever, its just that you wont like living in it. -- Hiranya Peiri
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