[FFmpeg-devel] [PATCH v1 4/6] avcodec/magicyuv: fix for the memory leak if failed

[Andreas Rheinhardt]

lance.lmwang at gmail.com:
> From: Limin Wang <lance.lmwang at gmail.com>
> 
> Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
> ---
>  libavcodec/magicyuv.c | 43 ++++++++++++++++++++++++++++++-------------
>  1 file changed, 30 insertions(+), 13 deletions(-)
> 
> diff --git a/libavcodec/magicyuv.c b/libavcodec/magicyuv.c
> index 0b1ac7345a..c905c2ca22 100644
> --- a/libavcodec/magicyuv.c
> +++ b/libavcodec/magicyuv.c
> @@ -661,12 +661,16 @@ static int magy_decode_frame(AVCodecContext *avctx, void *data,
>  
>      for (i = 0; i < s->planes; i++) {
>          av_fast_malloc(&s->slices[i], &s->slices_size[i], s->nb_slices * sizeof(Slice));
> -        if (!s->slices[i])
> -            return AVERROR(ENOMEM);
> +        if (!s->slices[i]) {
> +            ret = AVERROR(ENOMEM);
> +            goto fail;
> +        }
>  
>          offset = bytestream2_get_le32(&gbyte);
> -        if (offset >= avpkt->size - header_size)
> -            return AVERROR_INVALIDDATA;
> +        if (offset >= avpkt->size - header_size) {
> +            ret = AVERROR_INVALIDDATA;
> +            goto fail;
> +        }
>  
>          if (i == 0)
>              first_offset = offset;
> @@ -675,8 +679,10 @@ static int magy_decode_frame(AVCodecContext *avctx, void *data,
>              s->slices[i][j].start = offset + header_size;
>  
>              next_offset = bytestream2_get_le32(&gbyte);
> -            if (next_offset <= offset || next_offset >= avpkt->size - header_size)
> -                return AVERROR_INVALIDDATA;
> +            if (next_offset <= offset || next_offset >= avpkt->size - header_size) {
> +                ret = AVERROR_INVALIDDATA;
> +                goto fail;
> +            }
>  
>              s->slices[i][j].size = next_offset - offset;
>              offset = next_offset;
> @@ -686,28 +692,32 @@ static int magy_decode_frame(AVCodecContext *avctx, void *data,
>          s->slices[i][j].size  = avpkt->size - s->slices[i][j].start;
>      }
>  
> -    if (bytestream2_get_byte(&gbyte) != s->planes)
> -        return AVERROR_INVALIDDATA;
> +    if (bytestream2_get_byte(&gbyte) != s->planes) {
> +        ret = AVERROR_INVALIDDATA;
> +        goto fail;
> +    }
>  
>      bytestream2_skip(&gbyte, s->nb_slices * s->planes);
>  
>      table_size = header_size + first_offset - bytestream2_tell(&gbyte);
> -    if (table_size < 2)
> -        return AVERROR_INVALIDDATA;
> +    if (table_size < 2) {
> +        ret = AVERROR_INVALIDDATA;
> +        goto fail;
> +    }
>  
>      ret = init_get_bits8(&gbit, avpkt->data + bytestream2_tell(&gbyte), table_size);
>      if (ret < 0)
> -        return ret;
> +        goto fail;
>  
>      ret = build_huffman(avctx, &gbit, s->max);
>      if (ret < 0)
> -        return ret;
> +        goto fail;
>  
>      p->pict_type = AV_PICTURE_TYPE_I;
>      p->key_frame = 1;
>  
>      if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
> -        return ret;
> +        goto fail;
>  
>      s->buf = avpkt->data;
>      s->p = p;
> @@ -736,6 +746,13 @@ static int magy_decode_frame(AVCodecContext *avctx, void *data,
>      *got_frame = 1;
>  
>      return avpkt->size;
> +
> +fail:
> +    for (i = 0; i < FF_ARRAY_ELEMS(s->slices); i++) {
> +        av_freep(&s->slices[i]);
> +        s->slices_size[i] = 0;
> +    }
> +    return ret;
>  }
>  
>  #if HAVE_THREADS
> 
Why should there be a memleak? The slices buffer will be freed in
magy_decode_end (which is called from avcodec_close() (usually via
avcodec_free_context()) at the end of the decoding process). So how
did you detect this memleak?

- Andreas