[FFmpeg-devel] [PATCH v3] avcodec/frame_thread_encoder: Free AVCodecContext structure on error during init

[Andreas Rheinhardt]

Michael Niedermayer:
> Fixes: MemLeak
> Fixes: 8281
> Fixes: PoC_option158.jpg
> Fixes: CVE-2020-22037
> 
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  libavcodec/frame_thread_encoder.c | 11 +++++++----
>  libavcodec/frame_thread_encoder.h |  4 ++++
>  2 files changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/libavcodec/frame_thread_encoder.c b/libavcodec/frame_thread_encoder.c
> index 9cabfc495f..9bc48c7761 100644
> --- a/libavcodec/frame_thread_encoder.c
> +++ b/libavcodec/frame_thread_encoder.c
> @@ -126,7 +126,7 @@ int ff_frame_thread_encoder_init(AVCodecContext *avctx)
>  {
>      int i=0;
>      ThreadContext *c;
> -
> +    AVCodecContext *thread_avctx = NULL;
>  
>      if(   !(avctx->thread_type & FF_THREAD_FRAME)
>         || !(avctx->codec->capabilities & AV_CODEC_CAP_FRAME_THREADS))
> @@ -202,16 +202,17 @@ int ff_frame_thread_encoder_init(AVCodecContext *avctx)
>      for(i=0; i<avctx->thread_count ; i++){
>          int ret;
>          void *tmpv;
> -        AVCodecContext *thread_avctx = avcodec_alloc_context3(avctx->codec);
> +        thread_avctx = avcodec_alloc_context3(avctx->codec);
>          if(!thread_avctx)
>              goto fail;
>          tmpv = thread_avctx->priv_data;
>          *thread_avctx = *avctx;
> +        thread_avctx->priv_data = tmpv;
> +        thread_avctx->internal = NULL;
> +        thread_avctx->hw_frames_ctx = NULL;
>          ret = av_opt_copy(thread_avctx, avctx);
>          if (ret < 0)
>              goto fail;
> -        thread_avctx->priv_data = tmpv;
> -        thread_avctx->internal = NULL;
>          if (avctx->codec->priv_class) {
>              int ret = av_opt_copy(thread_avctx->priv_data, avctx->priv_data);
>              if (ret < 0)
> @@ -233,6 +234,8 @@ int ff_frame_thread_encoder_init(AVCodecContext *avctx)
>  
>      return 0;
>  fail:
> +    avcodec_close(thread_avctx);
> +    av_freep(&thread_avctx);
>      avctx->thread_count = i;
>      av_log(avctx, AV_LOG_ERROR, "ff_frame_thread_encoder_init failed\n");
>      ff_frame_thread_encoder_free(avctx);
> diff --git a/libavcodec/frame_thread_encoder.h b/libavcodec/frame_thread_encoder.h
> index 2cdc40a830..201cba2a8f 100644
> --- a/libavcodec/frame_thread_encoder.h
> +++ b/libavcodec/frame_thread_encoder.h
> @@ -23,6 +23,10 @@
>  
>  #include "avcodec.h"
>  
> +/**
> + * Initialize frame thread encoder.
> + * @note hardware encoders are not supported
> + */
>  int ff_frame_thread_encoder_init(AVCodecContext *avctx);
>  void ff_frame_thread_encoder_free(AVCodecContext *avctx);
>  int ff_thread_video_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
> 
LGTM.

- Andreas

PS: I still don't know whether my patch for av_opt_copy needs to bump
minor or micro.