avcodec/pngdec: fix possible race condition with APNG decoding

Fixes #9017

Paul B Mahol committed 5 years ago

Commit 63231fa1 parent bbf61831 file · +2 −2Browse files

Unified · Split

libavcodec/pngdec.c+2−2

@@ -711,13 +711,13 @@ static int decode_idat_chunk(AVCodecContext avctx, PNGDecContext s, · 710 unmodified lines
711	711	s->bpp += byte_depth;
712	712	}
713	713
714		− if ((ret = ff_thread_get_buffer(avctx, &s->picture, AV_GET_BUFFER_FLAG_REF)) < 0)
715		− return ret;
716	714	if (avctx->codec_id == AV_CODEC_ID_APNG && s->last_dispose_op != APNG_DISPOSE_OP_PREVIOUS) {
717	715	ff_thread_release_buffer(avctx, &s->previous_picture);
718	716	if ((ret = ff_thread_get_buffer(avctx, &s->previous_picture, AV_GET_BUFFER_FLAG_REF)) < 0)
719	717	return ret;
720	718	}
	719	+ if ((ret = ff_thread_get_buffer(avctx, &s->picture, AV_GET_BUFFER_FLAG_REF)) < 0)
	720	+ return ret;
721	721	p->pict_type = AV_PICTURE_TYPE_I;
722	722	p->key_frame = 1;
723	723	p->interlaced_frame = !!s->interlace_type;