int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
                        bool exact_size)
{
    BDRVQcowState *s = bs->opaque;
    int new_l1_size2, ret, i;
    uint64_t *new_l1_table;
    int64_t old_l1_table_offset, old_l1_size;
    int64_t new_l1_table_offset, new_l1_size;
    uint8_t data[12];

    if (min_size <= s->l1_size)
        return 0;

    if (exact_size) {
        new_l1_size = min_size;
    } else {
        /* Bump size up to reduce the number of times we have to grow */
        new_l1_size = s->l1_size;
        if (new_l1_size == 0) {
            new_l1_size = 1;
        }
        while (min_size > new_l1_size) {
            new_l1_size = (new_l1_size * 3 + 1) / 2;
         }
     }
 
    if (new_l1_size > INT_MAX) {
         return -EFBIG;
     }
#ifdef DEBUG_ALLOC2
    fprintf(stderr, "grow l1_table from %d to %" PRId64 "\n",
            s->l1_size, new_l1_size);
#endif

    new_l1_size2 = sizeof(uint64_t) * new_l1_size;
    new_l1_table = g_malloc0(align_offset(new_l1_size2, 512));
    memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));

    /* write new table (align to cluster) */
    BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ALLOC_TABLE);
    new_l1_table_offset = qcow2_alloc_clusters(bs, new_l1_size2);
    if (new_l1_table_offset < 0) {
        g_free(new_l1_table);
        return new_l1_table_offset;
    }

    ret = qcow2_cache_flush(bs, s->refcount_block_cache);
    if (ret < 0) {
        goto fail;
    }

    /* the L1 position has not yet been updated, so these clusters must
     * indeed be completely free */
    ret = qcow2_pre_write_overlap_check(bs, 0, new_l1_table_offset,
                                        new_l1_size2);
    if (ret < 0) {
        goto fail;
    }

    BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_WRITE_TABLE);
    for(i = 0; i < s->l1_size; i++)
        new_l1_table[i] = cpu_to_be64(new_l1_table[i]);
    ret = bdrv_pwrite_sync(bs->file, new_l1_table_offset, new_l1_table, new_l1_size2);
    if (ret < 0)
        goto fail;
    for(i = 0; i < s->l1_size; i++)
        new_l1_table[i] = be64_to_cpu(new_l1_table[i]);

    /* set new table */
    BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ACTIVATE_TABLE);
    cpu_to_be32w((uint32_t*)data, new_l1_size);
    stq_be_p(data + 4, new_l1_table_offset);
    ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_size), data,sizeof(data));
    if (ret < 0) {
        goto fail;
    }
    g_free(s->l1_table);
    old_l1_table_offset = s->l1_table_offset;
    s->l1_table_offset = new_l1_table_offset;
    s->l1_table = new_l1_table;
    old_l1_size = s->l1_size;
    s->l1_size = new_l1_size;
    qcow2_free_clusters(bs, old_l1_table_offset, old_l1_size * sizeof(uint64_t),
                        QCOW2_DISCARD_OTHER);
    return 0;
 fail:
    g_free(new_l1_table);
    qcow2_free_clusters(bs, new_l1_table_offset, new_l1_size2,
                        QCOW2_DISCARD_OTHER);
    return ret;
}

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.