static int mov_read_chan(MOVContext *c, AVIOContext *pb, MOVAtom atom)
{
    AVStream *st;
    uint8_t version;
    uint32_t flags, layout_tag, bitmap, num_descr, label_mask;
    int i;

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

    if (atom.size < 16)
        return 0;

    version = avio_r8(pb);
    flags   = avio_rb24(pb);

    layout_tag = avio_rb32(pb);
    bitmap     = avio_rb32(pb);
    num_descr  = avio_rb32(pb);

    if (atom.size < 16ULL + num_descr * 20ULL)
        return 0;

    av_dlog(c->fc, "chan: size=%" PRId64 " version=%u flags=%u layout=%u bitmap=%u num_descr=%u\n",
            atom.size, version, flags, layout_tag, bitmap, num_descr);

    label_mask = 0;
    for (i = 0; i < num_descr; i++) {
        uint32_t av_unused label, cflags;
        label     = avio_rb32(pb);          // mChannelLabel
        cflags    = avio_rb32(pb);          // mChannelFlags
        avio_rl32(pb);                      // mCoordinates[0]
        avio_rl32(pb);                      // mCoordinates[1]
        avio_rl32(pb);                      // mCoordinates[2]
        if (layout_tag == 0) {
            uint32_t mask_incr = ff_mov_get_channel_label(label);
            if (mask_incr == 0) {
                label_mask = 0;
                break;
            }
            label_mask |= mask_incr;
        }
    }
    if (layout_tag == 0)
        st->codec->channel_layout = label_mask;
    else
        st->codec->channel_layout = ff_mov_get_channel_layout(layout_tag, bitmap);

    return 0;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.