ff_rm_parse_packet (AVFormatContext *s, AVIOContext *pb,
                    AVStream *st, RMStream *ast, int len, AVPacket *pkt,
                    int *seq, int flags, int64_t timestamp)
{
    RMDemuxContext *rm = s->priv_data;
    int ret;

    if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
        rm->current_stream= st->id;
        ret = rm_assemble_video_frame(s, pb, rm, ast, pkt, len, seq, &timestamp);
        if(ret)
            return ret < 0 ? ret : -1; //got partial frame or error
    } else if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
        if ((ast->deint_id == DEINT_ID_GENR) ||
            (ast->deint_id == DEINT_ID_INT4) ||
            (ast->deint_id == DEINT_ID_SIPR)) {
            int x;
            int sps = ast->sub_packet_size;
            int cfs = ast->coded_framesize;
            int h = ast->sub_packet_h;
            int y = ast->sub_packet_cnt;
            int w = ast->audio_framesize;

            if (flags & 2)
                y = ast->sub_packet_cnt = 0;
            if (!y)
                ast->audiotimestamp = timestamp;

            switch (ast->deint_id) {
                case DEINT_ID_INT4:
                    for (x = 0; x < h/2; x++)
                        readfull(s, pb, ast->pkt.data+x*2*w+y*cfs, cfs);
                    break;
                case DEINT_ID_GENR:
                    for (x = 0; x < w/sps; x++)
                        readfull(s, pb, ast->pkt.data+sps*(h*x+((h+1)/2)*(y&1)+(y>>1)), sps);
                    break;
                case DEINT_ID_SIPR:
                    readfull(s, pb, ast->pkt.data + y * w, w);
                    break;
            }

            if (++(ast->sub_packet_cnt) < h)
                return -1;
            if (ast->deint_id == DEINT_ID_SIPR)
                ff_rm_reorder_sipr_data(ast->pkt.data, h, w);

             ast->sub_packet_cnt = 0;
             rm->audio_stream_num = st->index;
            if (st->codecpar->block_align <= 0) {
                av_log(s, AV_LOG_ERROR, "Invalid block alignment %d\n", st->codecpar->block_align);
                return AVERROR_INVALIDDATA;
            }
             rm->audio_pkt_cnt = h * w / st->codecpar->block_align;
        } else if ((ast->deint_id == DEINT_ID_VBRF) ||
                   (ast->deint_id == DEINT_ID_VBRS)) {
            int x;
            rm->audio_stream_num = st->index;
            ast->sub_packet_cnt = (avio_rb16(pb) & 0xf0) >> 4;
            if (ast->sub_packet_cnt) {
                for (x = 0; x < ast->sub_packet_cnt; x++)
                    ast->sub_packet_lengths[x] = avio_rb16(pb);
                rm->audio_pkt_cnt = ast->sub_packet_cnt;
                ast->audiotimestamp = timestamp;
            } else
                return -1;
        } else {
            ret = av_get_packet(pb, pkt, len);
            if (ret < 0)
                return ret;
            rm_ac3_swap_bytes(st, pkt);
        }
    } else {
        ret = av_get_packet(pb, pkt, len);
        if (ret < 0)
            return ret;
    }

    pkt->stream_index = st->index;

    pkt->pts = timestamp;
    if (flags & 2)
        pkt->flags |= AV_PKT_FLAG_KEY;

    return st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO ? rm->audio_pkt_cnt : 0;
}

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.