static int cloop_open(BlockDriverState *bs, QDict *options, int flags,
                      Error **errp)
{
    BDRVCloopState *s = bs->opaque;
    uint32_t offsets_size, max_compressed_block_size = 1, i;
    int ret;

    bs->read_only = 1;

    /* read header */
    ret = bdrv_pread(bs->file, 128, &s->block_size, 4);
    if (ret < 0) {
        return ret;
    }
    s->block_size = be32_to_cpu(s->block_size);
    if (s->block_size % 512) {
        error_setg(errp, "block_size %u must be a multiple of 512",
                   s->block_size);
        return -EINVAL;
    }
    if (s->block_size == 0) {
        error_setg(errp, "block_size cannot be zero");
        return -EINVAL;
    }

    /* cloop's create_compressed_fs.c warns about block sizes beyond 256 KB but
     * we can accept more.  Prevent ridiculous values like 4 GB - 1 since we
     * need a buffer this big.
     */
    if (s->block_size > MAX_BLOCK_SIZE) {
        error_setg(errp, "block_size %u must be %u MB or less",
                   s->block_size,
                   MAX_BLOCK_SIZE / (1024 * 1024));
        return -EINVAL;
    }

    ret = bdrv_pread(bs->file, 128 + 4, &s->n_blocks, 4);
    if (ret < 0) {
        return ret;
    }
     s->n_blocks = be32_to_cpu(s->n_blocks);
 
     /* read offsets */
     offsets_size = s->n_blocks * sizeof(uint64_t);
     s->offsets = g_malloc(offsets_size);
        if (i > 0) {
            uint32_t size = s->offsets[i] - s->offsets[i - 1];
            if (size > max_compressed_block_size) {
                max_compressed_block_size = size;
            }
        }
    }

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.