static AVCodec *find_encdec(enum AVCodecID id, int encoder)
{
    AVCodec *p, *experimental = NULL;
    p = first_avcodec;
    id= remap_deprecated_codec_id(id);
    while (p) {
        if ((encoder ? av_codec_is_encoder(p) : av_codec_is_decoder(p)) &&
            p->id == id) {
            if (p->capabilities & AV_CODEC_CAP_EXPERIMENTAL && !experimental) {
                experimental = p;
            } else
                return p;
        }
        p = p->next;
    }
    return experimental;
}

The product writes data past the end, or before the beginning, of the intended buffer.