static int mov_read_pasp(MOVContext *c, AVIOContext *pb, MOVAtom atom)
{
    const int num = avio_rb32(pb);
    const int den = avio_rb32(pb);
    AVStream *st;

    if (c->fc->nb_streams < 1)
        return 0;
    st = c->fc->streams[c->fc->nb_streams-1];

    if ((st->sample_aspect_ratio.den != 1 || st->sample_aspect_ratio.num) && // default
        (den != st->sample_aspect_ratio.den || num != st->sample_aspect_ratio.num)) {
        av_log(c->fc, AV_LOG_WARNING,
               "sample aspect ratio already set to %d:%d, ignoring 'pasp' atom (%d:%d)\n",
               st->sample_aspect_ratio.num, st->sample_aspect_ratio.den,
               num, den);
    } else if (den != 0) {
        av_reduce(&st->sample_aspect_ratio.num, &st->sample_aspect_ratio.den,
                  num, den, 32767);
    }
    return 0;
}

The product performs an iteration or loop without sufficiently limiting the number of times that the loop is executed.